CHEMISTRY OF NATURAL PRODUCTS

DISSERTATION SUBMITTED FOR THE DEORJSfl OP

MASTER OF PHILOSOPHY IN

C H E M I S T R Y

MANSOOR AHMAD

DEPARTMENT OP CHEMISTRY A U O A R H MUSLIM UNIYERSmr

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CERTIFICATE

The dissertation entitled 'Cheinistry of

Natural Products' is the original work of

Mr. Mansoor Anmad and this work is sufficient

for partial fulfilment of the requirements

for the degi e of Master of Philosophy in Chemistry

(Dr. MdrW. Kamil)

Co-supervisor

(Prof . M: Ilyas)

Supervisor

C O N T E N T S

1. INTRODUCTION

2. THEORETICAL

a. Classification

REFERENCES

b. Structure. Determination

REFERENCES

3. DISCUSSION

4. EXPERIMENTAL

Page

1-3

4-7

8-12

13-27

27A

28-36

37-40

ACKNOWLEDGEMENTS

I wish to express my sincere thanks to Prof.

M. Ilyas and Dr. M. Kamil, who not only guided me

but inspired me at all stages. Without their keen

interest, affectionate supervision and constant help

throughout, it would have been impossible to complete

this work.

I am very much thankful to Prof. S.M. Osman,

Chairman, Department of Chemistry, AMU, Aligarh for

providing me the necessary facilities for the executions

of the work.

I would like to thanks Prof. Saleem Siddiqui,

Dr. Sarwar Alam and Miss. Neeru Jain, for providing

plant materials.

I also wish to record my thanks to all my lab

colleauges and friends.

In the last, but certainly not the least, it is

with immense pleasure that I place on record my heartfelt

gratitude and indebtness to my father Ch. Bashir Ahmad

Ghatyalian, who has been intrumental and constant source

of inspiration in the accomplishment of the present work.

.. . 0

('MANSOOR AHMAD )

INTRODUCTION

Phytochemistry developed as a distinct discipline deals

with the chemical structure, biosynthesis, natural distribution

and biological function of organic substances accumulated by

plants. It has an established role in all branches of plant

science such as Physiology, Pathology, ecology, alaeobotany,

systematics and genetics. There are between 2,50,000 and

3,00,000 species of higher plants, yet less than 300 have been

grown to any appreciable extent under domestication.

Investigation of drug plant used in indegenous medicine

in India was started during the early part of the present

century. Since 1940's onwards new vegetable drugs came into

prominence so much so that approximately one third of pharma­

ceuticals are of plant origin. Therefore, it is the plant—

the chemical laboratory of nature which first gives us a clue

to more and more kinds of active principles useful for mankind.

Because of abundance and chief supply of petrochemicals for

chemical manufacture, research to exploit plant source of bio­

logically active chemicals, and of intermediates for partial

synthesis, has been almost universally overlooked. Much great*

emphasis on the exploitation of plants as sources of chemicals

can be expected in future. Consequently, there has been a

return to natural products as 'sources of inspiration for the

organic chemist'.

: 2 :

Based on new experimental techniques now used in

phytochemical research, the structure elucidation of natural

products and their synthesis has undergone a veritable renai­

ssance. Natural products mostly serve as proto types for more

active and less toxic analogues obtained by molecular

modifications.

Chromatographic and spectroscopic instrumentation have

greatly shortened the time needed for organic chemical studies

and have increased accuracy in judging homogeneity and purity

of materials manifold. The innovation of countercurrent

distribution and chromatography particularly thinlayer and gas

liquid chromatography have led to the use of these techniques

as criteria of identification. Frequently the chemical identi­

fication of plant products is based exclusively on the similarit

of R^ values or retention times with those of reference

compounds of known structures. Unfortunately because of the

lack of specificity of these techniques such criteria are

insufficient broof of the chemical identity of plant product.

Thus, more specific information such as infrared, nuclear

magnetic resonance and mass spectrometry data and more recently 13

C-NMR and G C. MS studies are essential requirements for

unequivocal establishment of chemical structure. The main

corrections of old mistakes continue to occur in stereochemistr-j

of the natural products since organic chemist* have learned to

determine absolute configurations and preferred conformation by

• 3 •

1 13 soentgeno graphic analysis, by H and C-NMR spectroscopy

and by measurements of circular dichroism.

Although our country abounds in medicinal herbaceous

flora, very few indegenous plants have been subjected to

phytochemical study for the characterization of active prin­

ciples. This inspired us to investigate some medicinally

important plants for presence of active compounds of possible

therapeutic uses.

The following two plants were investigated for their

chemical constituents :

1. Quercus infectoria

2. Siteria etalica

Biflavonoids and steroids are the main constituents

isolated and characterised from these plants. A brief

account of literature in each Case is described.

REFERENCES

1. Peach, K. and Tracey, M.V., 'Modern Methods of Plant analysis', Springer Verlag, 1955-56, 1-4,

2. Robinson, T,, 'The Organic Constituents of Higher Plants', Burgers Publishing Company, 1987.

CLASSIFICATION

The Biflavonoids are classified under two main

headings :

[A] C-C Linked biflavonoids

[B] C-O-C Linked biflavonoids

[Aj C-C linked biflavonoids

C-C linked biflavonoids are subdivided into the following

series depending upon the nature of the constituent monomeric

units and on the position of the linkage.

1. Aqathisflavone series : The series consists of six bifla-2—7 vonoids • The parent member is agathisflavone derived

from two apigenin units with [l-6,II-8j linkage,

o

2. Rhus flavanone : This is derived from two naringenin units

with [1-6,11-8] linkage.

3. Rhusflavone ; This flavanone-flavone is derived from

naringenin and apigenin units linked through [l-6,II-8].

4. Amentoflavone series : The parent compound of this series

is amentoflavone, derived from two apigenin units with

tl-3',II-8] linkage and are represented by sixteen members

members- *-'- " .

: 5 :

5, I-2.3-Dlhvciroamentoflavone series : The biflavonoid

compound of this series are derived from a naringenin

and an apigenin unit with flavanone [l-3',II-8] linkage,

18 28 and are represented by four members ' with I-2,3-di-

hydroamentoflavone as the parent compound.

6. Tetrahvdroamentoflavone series : 1-2,3 II-2,3-tetrahydro-

amentoflavone has been isolated from the nuts of Semecarous

29 30 anacardium * . Thirteen more closely related tetrahydro-biflavonoid compounds have also been isolated from other

31-33 semecarpus species .

7. Cupressuflavone series : Cupressuflavone series comprises 3 jt O "3

of dimers of apigenin and its partial methyl ether * *

ether' ' ' ' ' '*"'* with Ll-8,II-8] linkage. The parent

2 34 compound is cupressuflavone ' .

8. Musuaferone-A and Musuaferone-B t Subba Rao et al. have

reported the isolation of 1-2,3,11-2,3-tetrahydrocupressu-

41 flavone - Musuaferone-A and I-2,3-dihydrocupressuflavone-

42 Musuaferone-B from the stamens of Mesua ferrea.

9. Robustaflavone series : This class is represented only by 55 56

robustaflavone ' and is derived from two apigenin units

with [l-3',II-6] linkage. Before the isolation of robusta-

flavone from natural source, its hexaraethyl ether had been

prepared by Wesseley-Moser rearrangement of amentoflavone

hexamethyl ether.

: 6 :

45

10. Ablesln : Chatterjee et al have recently isolated abiesin

from Abies Webbiana. It is derived from a flavone and a

flavonol unit with [l-3',II-6] linkage.

11, Succedaneaflavanone : This is derived from two naringenin

units with [l-6,II-6] linkage and isolated from Rhus Succedanea. However, its hexamethyl ether has been synthe-

47 sized by Parthasarthy et al.

12. Taiwaniaflavone series : A new series of naturally occuring

biflavone have been derived from Taiwania cryptomerioides

Hayata^^ These are derived from two apigenin units with

[l-3,II-3'] linkage. Although [l-3,II-3'] biapigenin has

48 been reported eailier but this constitutes the first

example of its occurrence from a natural source.

49—64 13, G.B, Series ! This series comprises of reduced hetro-

cyclic system and are derived from a naringenin linked with

naringenin or aromadendrin or taxifolin or eriodictyol

through [l-3,II-8] linkage.

14, BGH_Series^^'^^~*^^ : There are derived from a naringenin

and an apigenin or luteolin units with flavanone [l-3,II-8]

flavone linkage and are represented by BGH-II and BGH-III

as the parent compound respectively,

55 59 15. WGH Series * : Two biflavones, WGH-II and WGH-III have

: 7 :

been synthesized by dehydrogenation of BGH-II and

BGH-III respectively.

16. I-4'.I-5.II~5.I-7.II-7-Pentahvdroxvflavanone [I-3.II-83

chromone : This compound has been isolated from the

leaves of Garcinia vp. is Kurz, It is a dimer of naringenin

and 5,7-dihydroxy chromone linked through [l-3,II-8].

Its isolation has introduced a new series comprising of

flavanone chromono structure.

[B] C-O-C Linked biflavonoids

1. Hinokiflavone series * * *" : These are derived from

two aplgenin units with [I-4'-0-II-6] linkage, Hinokifla­

vone is the parent compound with six(6) others as its

partial methyl ethers.

2. 1-2.3-Dihvdrohinokiflavone : The sole number has been

isolated from Metasequoia qlvptostroboides and cvcas

species^®'^®.

3. Ochnaflavone series : This class is represented by five

members-"-" ' ' . Kamil et al. have isolated II-7-O-methyl

Ochnaflavone ' from the leaves of Ochna pumila.

REFERENCES

1. W. Baker, A.CM. Finch, W.D. Ollis and K.W. Robinson, J. Chem. Soc, 1477 (1963).

2. A. Pelter, R. Warren, B.K. Handa, K.K. Chexal and W. Rahman, Ind. J. Chem., 9, 98 (1971).

3. N.U. Khan, M. Ilyas, W. Rahman, T. Mashima, M. Okigawa and N. Kawano, Tetrahedron, 28, 5689 (1972).

4. A. Pelter, R. Warren, J.N. Usmani, R.H. Rizvi, M. Ilyas and W. Rahman, Experientia, 25, 351 (1969).

5. N.U. Khan, M. Ilyas, W. Rahman, M. Okigawa and N. Kawano, Tetrahedron letters, 33, 2941 (1970).

6. N. Ilyas, M, Ilyas, W, Rahman. M. Okigawa and N. Kawano, Phytochemistry, 17, 987 (1978).

7. B.K. Handa, K.K. Chexal, T. Mah and W. Rahman, J. Ind. Chem. Soc, 48, 17 (1971).

8. F.C. Chen, Y.M. Lin and J.C. Wu, Phytochemistry, j^, 1571 (1974).

9. Y.M. Lin, F.C. Chen, Tetrahedron letters, 4747 (1973).

10. R. Madhav, Tetrahedron letters, 2017 (1969).

11. M. Okigawa, N. Kawano, M. Aqil and W. Rahman, Tetrahedron letters, 2003 (1973).

12. V.L. Horhammer, H. Wagner and H, Reinhardt, Naturwlssen-schaften, 52, 161 (1973).

13. A. Pelter, R. Warren, N. Hameed, N.U. Khan, M. Ilyas and W. Rahman, Phytochemistry, 9, 1987 (1970).

14. T. Karriyone and N. Kawano, J. Pharm. Soc, Japan, 76, 451 (1958).

15. H. Miura and N. Kawano, J. Pharm. Soc, Japan, 8, 1489 (1968).

16. B.K. Handa, K.K. Chexal, W. Rahman, M, Okigawa and N. Kawano Phytochemistry, 10, 436 (1971).

: 9 :

17. N. Kawano and M. Yamada, J. Am. Chem. Soc, 82, 1505(1960).

18. S. Beckmann, H. Geiger and W. de Grootpfleiderer, Phytochemistry, 10, 2465 (1971).

19. K.K. Chexal, B.K, Handa, W. Rahman and N. Kawano, Chem Ind., 28 (1970).

20. H. Miura, T. Kihara and N. Kawano, Tetrahedron letters, 2339 (1968).

21. H. Miura, T. Kihara and N. Kawano, Chem. Pharm. Bull.(Tokyo), 17, 150 (1969).

22. M. Kamil, M. Ilyas, W. Rahman, N. Okigawa and N. Kawano, J. Chem. Soc, Perkin-I 553 (1981).

23. N.U. Khan, W.H. Ansari, W. Rahman, M. Okigawa and N. Kawano, Chem. Pharm. Bull.(Tokyo) 19, 1500 (1971).

24. N. Chandramouli, S. Natrajan, V.V.S. Murti and T. Sheshadri, Ind. J. Chem., 9, 895 (1971).

25. A. Pelter, R. Warren, M. Ilyas, J.N. Usmani, S.P. Bhatnagar, R.H. Rizvi, M. Ilyas and W. Rahman, Experientia, 25, 350, (1969).

26. R. Hodges, Aus. J. Chem., 8, 1491 (1965).

27. S.F. Dossaja, E.A. Bell and J.W. Wallace, Phytochemistry, 12, 371 (1973).

28. A*K. Varshney, T. Mah, N.U. Khan, W. Rahman, M. Okigawa and N. Kawano, Ind. J. Chem., il, 1209 (1973).

29. I. Ahmad, K. Ishratullah, M. Ilyas, W. Rahman. 0. Seligmann and H. Wagner, Phytochemistry, 20, 1169 (1981).

30. K. Ishratullah, W.H. Aiisari, W, Rahman, M. Okigawa and N. Kawano, Ind. J. Chem., 15B. 615 (1977).

31. N.S. Rao, L.R. Row and R.T. Brown, Phytochemistry, 12, 671 (1973).

32. S.S.N. Murthy, Phytochemistry, £2, 1518 (1983).

33. S.S.N. Murthy, Phytochemistry, 22, 2636 (1983).

34. V.V.S. Murti, P.V. Raman and T.R. Sheshadri, Tetrahedron, 23, 397 (1967), Tetrahedron letters, 2995 (1964).

: 10 :

35. H.M. Taufeeq, W. Fatma, M. Ilyas, W. Rahman and N. Kawano, H.M. Tauteeq, w. i-atma, M. ilva Ind. J. Chem., i6B, 655 (1978).

36. T. Mashima, M. Okigawa, N. Kawano, N.U. Khan, M. Ilyas and W, Rahman, Tetrahedron letters, 33, 2937 (1970).

37. M. Ilyas, J.N. Usmani, S.P. Bhatnagar, W. Rahman and A. Pelter, Tetrahedron letters 53, 5515 (1968).

38. W. Rahman and S.P. Bhatnagar, Tetrahedron letters, 675 (1968).

39. S. Natrajan, V.V.S. Murti and T.R. Sheshadri Ind. J. Chem., 8, 113 (1970).

40. K. Nakazawa, Chem. Pharm. Bull. (Tokyo) 10, 1032 (1962).

41. M.S. Raju, G, Srimannarayana and N.V. Suba Rao, Ind. J. Chem., 16B, 124 (1978),

42. M.S. Raju, G. Srimannarayana and N.V. Suba Rao, Tetrahedron letters, 49, 4509 (1976).

43. A.K. Varshney, W. Rahman, M. Okigawa and N. Kawano, Experientia, 29, 784 (1970).

44. K.K. Chexal, B.K. Handa and W. Rahman, J. Chromatog., 48, 484 (1970).

45. A. Chatterjee, J. Kotoky, T. Chakraborty, J. Banerji and K.K. Das. Proc. 71st Ind. Sc. Cong., Part III Abstract 138, 66 (1984).

46. F.C. Chen and J.J.M. Lin, Phytochemistry, lA, 1644 (1975).

47. M.R. Parthasarthy, K.R. Ranganathan and P.K. Sharma, Ind. J. Chem., 15B, 942 (1977).

48. R.J. Molyneux, A.C. Waiss Jr. and W.F. Haddon, Tetrahedron, 26, 1409 (1970).

49. B. Jackson, H.D. Locksley and F. Schienmann, J. Chem. Soc. (C), 3791 (1971).

50. E.G. Crichton and P.G. Waterman, Phytochemistry, 18, 1553 (1979). ^

: 11 :

51. B. Jackson, H.D. Locksley, F. Schienmann and W.A. Walstenholme. Tetrahedron letters, (a) 787 (1967) and (b) 3049, 4095 (1967).

52. A. Pelter, Tetrahedron letters, 1767 (1967), 897 (1968).

53. B. Jackson, H.D. Locksley, F. Schienmann and W.A. Walstenholme, Chem. Conun., 1125, 1360 (1968).

54. P.J. Coterill and F. Schienmann, J. Chem. Soc, Perkin-Trans I, 6, 531 (1978).

55. A. Pelter, R. Warren, K.K. Chexal, B.K. Handa and W. Rahman Tetrahedron , 27, 1625 (1971),

56. C.G. Karanjgaokar, P.V. Radhakrishnan and K. Venkatraman, Tetrahedron letters, 3195 (1967).

57. M. Konoshima, Y. Ikeshiro, A. Nishinaga, T. Matsura, T. Kubota and H. Sakamato, Tetrahedron letters, 2., 121(1969),

58. M. Konoshima, Y. Ikeshiro, Tetrahedron letters, 20, 1717 (1970).

59. Y. Ikeshiro and M. Konoshima, Tetrahedron letters, 4383 (1972).

60. B.S. Joshi, V.N. Kamat and Viswanathan, Phytochemistry, 9, 881 (1970).

61. W.H. Ansari, W. Rahman, D. Barrackough, R. Maynord and F. Schienmann, J. Chem. Soc, Perkin I, 1458 (1976).

62. A. Pelter, R. Warren, J.N. Usmani, M. Ilyas and W. Rahman, Tetrahedron letters, 45, 4259 (1969).

63. H. Miura and N. Kawano, Chem, Pharm. Bull. (Tokyo), 16, 1838 (1968).

64. H. Miura, N. Kawano and A.C. Waiss Jr., Chem. Pharm. Bull. (Tokyo), 14, 1404 (1966),

65. H. Miura and N. Kawano, J. Pharm. Soc, Japan, 80, 746 (1960). "~

66. F.C. Chen, Y,M, Lin and C M , Liang, 3, 276 (1974),

67. M. Okigawa, N. Kawano, M, Aqil and W. Rahman, J, Chem,Soc, Perkin I, 580 (1976).

: 12 :

68. M* Karail, N.A. Khan, M. Ilyas and W. Rahman, Ind. J. Chem., 22B. 608 (1983).

69. M. Kamil, N.A. Khan, M.S. Alam and M. Ilyas, Phytochemistry, Vol. 26, 4, 1171-73 (1987).

STRUCTURE DETERMINATION OF BIFLAVONOIDS

A number of the problems arises during the structure

determination of a new compound. The complications during

the structure determination of a biflavonoid may be listed

as :

[a] occurence of more than one biflavonoid in chromatographi-

cally homogeneous fractions with the consequent difficulty

in their isolation in pure form.

[bj insolubility in usual organic solvents.

[c] the difficulties in exact location of 0-methyl group in

partially methylated derivatives of biflavones and

[d] the intricate problem of establishing the interflavonoid

linkage.

There are so many methods for determining the structure.

The physical methods and synthesis are of key importance for

the complete structure elucidation of biflavonoids,

1. Colour reactions

2. Spectroscopic methods

3. Degradation

4. Synthesis

Since mainly colour reactions and spectroscopic techniques

: 14 :

( H-NMR, Mass and UV) have been used in the identification and

structure determination of the products isolated from the plant

source during the course of present work, a short review of

each techniques is given.

[l] Colour reactions : Various colour reactions are reported

in the literature for the detection of certain structural

features among flavonoids. As the colour development

depends upon the pattern of hydroxylation and substitution,

its diagnostic value is only a broad indication. The

reagent generally used for colour reactions are magnesium-

2 3 hydrochloric acid , sodium amalgam-hydrochloric acid ,

4 5

Wilson boric acid and Zinc-hydrochloric acid . Biflavono-

ids are found to give more or less the same colour reactions

as monomers. [2] Spectroscopic methods :

(a) Ultra-violet spectroscopy : The ultra-violet spectra

of different flavonoids are very characteristic and along-

with colour reactions , have been used extensively to

distinguish the various groups of this class of compounds.

The absorption maxima of flavones have been correlated to

the presence of a benzoyl (I) and Cinnaraoyl (II) groupings.

The former giving rise to the low wavelength band at 240-

270nm and the latter to the high wavelength band at 320-

380nra.

: 15 :

0-

(I) (II)

On the basis of this generalisation, important deducations

have been made about the location of substituents in the two

rings.

Substitution in the ring B especially at 4' stabilizes

the cinnamoyl chromophore resulting in a bathochromic shift

of band I whereas substitution in the A ring has a similar,

effect on the position of band II. Compounds having a free

5-hydronyl absorb at higher wavelength and methylation of this

hydroxyl group brings about a hypsochromic shifts of 10-12nm

of both maxiaiawt" The presence of a hydro3<;yl group at this

position is routinely established by measuring the spectra in Q

presence of AlCl^ . Hydroxyl groups at 7,4' are more acidic

than others and a bathochromic shift of band I or band II or

addition of fused sodium acetate is a good indication of the

presence of hydroxyl groups at these positions but the result

of these measurements have to be interpreted with caution.

Presence of hydroxyl group at 4* is also confirmed by a large

bathochromic shift in band I without a decrease in intensity on

the addition of sodium methoxide . Ortho hydroxyl groups in

: 16 :

ring A and ring B are identified by a bathochromic shift in

band I in the presence of AlCl^ and sodium acetate/boric acid

respectively.

In flavanones and isoflavones, absence of cinnamoyl

chromophore has the effect of supressing the high wave length

band which is either totally absent or present only as inflectior

The ultra-violet spectra of biflavonyls are very similar

to that of the monoflavonoid unit with the only difference

that the molecular extinction coefficient ( ) of the biflavone

is approximately double as compared to the corresponding mono-

flavonoid. This demonstrates the presence of two isolated

chromophores of flavonoids per molecule of biflavonoid.

NMR Studies on biflavonoids :

The application of NMR spectroscopy has proved to be most

powerful and indespensible tool in the structure determination

of flavonoids. A lot of useful informations can be obtained

in the structure elucidation of biflavonoids by making a

comparison of their NMR spectra with those of their correspond­

ing monomers. Double irradiation technique helps to assign

each and every proton in the molecule.

Comparison of the NMR spectra of methyl and acetyl

: 17 :

derivatives of a biflavonoid with those of biflavonoids of

the same series as well as with those of biflavonoids of the

other series in which at least one monoflavonoid unit is

similarly constituted, is very helpful in assigning each and

individual protors of the methoxy groups. The problem of

interflavonoid linkage has been successfully solved by following

two techniques :

(a) The solvent induced shift studies of methoxy. resonance

(b) The lanthanide induced shift studies,

9-11 Benzene induced shifts of aromatic methoxy groups are

a useful aid in the elucidation of the structures of various

classes of natural products,

12 Wilson et al, while measuring the PMR spectra fttst

in CDCIQ and then in C,H, have observed that size of the benzene o 6 6

induced shift (A) of certain methoxy signals was to some

extent indicative of the position of the methoxy group on the

flavone nucleus. Methoxy groups at C-5, C-7, C-2', C-4'

exihibit large positive values (^= d CDCI3 7 d C,H, y 0,5 -

0.8 ppm) in the absence of OMe or OH substituents ortho to

these groups. In contrast, OMe group at C-3 or those flanked

by two ortho OMe functions (or one ortho - OH and one ortho-OMe

function) show small positive or negative values. An OMe at

C-5 suffers a drastic algebraic decrease in solvent shift upon

: 18 :

the introduction of an OMe group at C-6.

The benzene induced solvent shifts [^(CHCl3/C^H^)] of

certain methoxy groups in flavones are appreciably enhanced

by the addition of small quantity (3% v/v) of trifluoro acetic

acid (TFA) to the solution of flavone in benzene.

The possibility of using other solvents to obtain additi­

onal information has been considered and accordingly lanthanide

shift reagents ~ (LSR) have been extensively used for the

structural and conformational studies of organic natural

14-17 products

Commonly used lanthanide reagents are trischelates of

lanthanide ions with diketones, 2,2,6,6-tetramethyl heptane-3,

5 dione (dipivaloylmethane) and 1,1,12,2,3,3-heptafluoro-7-

7-dimethyl octane-4,6-dione. Typical shift reagents are tris-

(dipivaloylmethanato) europium and tris-1,1,1,2,2,3,3-hepta-

fluoro-7,7-dimethyloctane-4,6-dianato europium, the names of

which are normally abbreviated to Eu(dpm)2 and EuCfod)^.

Mass spectrometry : It plays a very active role in determining

the structure of monoflavonoids, biflavonoids, as well as ter­

penoids by fragmentation pattern relationship. The retro Diel's-

Alder (RDA) reaction is the principal mode of fragmentation in

flavones and biflavones. Most flavonoids yield intense peaks

for the molecular ion (Mt) and indeed this is often the base peak

: 19 :

In addition, flavonoids usually afford major peak for

(M-H) and, \when methylated (M-CHI) , The common fragmentation 1 o

processes of flavone are shown in chart below using apigenin

as a example.

Apigenin :

m/e 269(13)

OH

M**", m/e 270(100)

<r

OH jH

m/e 153(22) 4

m /e 121(6)

Nl/

m, /e 124(18)*^ -CO

-H'

/r\-'/ \ V ^ H ' '

V m/e 152

ra/e 123(10)

: 20 :

Amentof j.avone hexamethyl ether

The mode of fragmentation of amentoflavone hexamethyl

ether is shown below : m/e 592(8) // \\

m/e 621(3)

t -H*

-CH; /e 607(33^ -^ >H

t m /e 311

-CH5 ^3^° +0H

H3CO

OCH,

H3CO 0 m/e 135(16)

v:. M"*", m/e 622(100) H3CO 0

m/e 180(3)

OCH3O

m/e 576(10)

Main peaks (m/e: i n t e n s i t y ) : 622(100) , 621(31) , 607(33) , 592

( 8 ) , 576(10) , 3 1 2 ( 2 ) , 245 (5 ) , 1 8 1 ( 2 ) , 135(16) and 1 3 2 ( 3 ) .

: 21 : Cupressuflavone hexamethvl ether :

The mode of fragmentation of cupressuflavone hexamethyl

ether is given below :

OCH 3 P

-> m/e 576(4)

-> m/e 621(38)

^"3 ^ m/e607(8) "^"^> m/e592(l8)

OCH3 0

OCH3 0

m/e 245(11)

m/e 132(14)

(490 appears at m/e 245]

Main peaks : 622(100), 621(38), 607(8), 592(18), 576(4),

312(7), 311(14), 245(11), 135(26), and

132(14).

H i n o k i f l a v o n e Pentamethyl e t h e r : : 22 :

m/e 312 ^ m/e 3 1 3 ( 1 0 0 ) -

H^CO OCH:

+ 0 H3C

OCH3 0

m/e 3 1 1 ( 2 2 ) 4,

/ \ m / e 1 3 5 ( 1 9 )

\ ^ ' " 3 C 0

OCH: •,0

D

i /e 2 9 6 ( 7 5 ) H,CO +,

m/e 1 3 2 ( 8 ) m/e 1 8 1 ( 1 1 )

HTCO

•*• m / e 431

2 1

OCH3 ° C l e a v a g e

M^, m/e 6 0 8 ( 3 9 )

m/e 5 7 9 ( 1 1 )

C l e a v a g e 1

/ B \V "3^0

m/e 5 9 3 ( 3 6 )

-CH-

m/e 5 7 8 ( 1 1 ) m/e 6 0 7 ( 1 2 )

>- +

OCH, 0

m/e 2 8 1 ( 2 2 )

00 H3 0

m/e 327(23) m / e 2 9 6 ( 7 5 )

: 23 :

The fragmentation of hinokiflavone pentamethyl ether is

different from these amentoflavone, cupressuflavone and

agathisflavone hexamethyl ethers.

Main peaks :

608(39), 607(12), 593(36), 560(4), 579(ll), 578(11),

576(6), 431(7), 327(23), 313(100), 312(22), 311(22),

304(2), 297(29), 296(75), 281(22), 181(11), 180(3),

135(19) and 132(18).

REFERENCES

1. F.M. Dean, 'Naturally occurring oxygen ring compounds', London, Butterworths, P-287, 335 (1963).

2. J. Shinoda, J. Pharm. Soc, Japan, 48, 214 (1928).

3. V. Ashafaiva and Inubuse, Ber., 61B, 1646 (1928).

4. C.W. Wilson, J. Am. Chem. Soc, 6i, 2303 (1939).

b. J.C. Pew, J. Am. Chem. Soc, 70, 3031 (1948).

6. O.R. Gottlieb. In 'The Flavonoido' (J.B. Harbone, T.J. Mabry and H. Mabry, edo.), Chapman and Hall, London (197b).

7. L. Jord and R.M. Horowitz, J. Org. Chem., 22, 1618 (1957).

8. T.J. Mabry, K.R. Markham and M.B. Thomas, The SyBtematic Identification of flavonoids, Springer - Verleg, New York, Heidelberg (1970).

9. J.H. Bowie, J. Ronaye and D.H. Williams, J. Chem. Soc, (B), 285, (1966).

10. J.H. Bowie, D.W. Cameron, P.E. Schulz and D.H. Williams, Tetrahedron, 22, 1771 (1966).

11. J.H. Bowie, J. Ronaye and D.H. William, J. Chem, SOC.(B), 535 (1967).

12. R.C, Wilson, J.H. Bowie and D.H. Williams, Tetrahedron, 24, 1407 (1968).

13. A.F. Cockerill, G.L.O. Davis and D.M. Rackam, Chemical Reviews, 73, 553 (1973).

14. J.K.M. Sender and D.H. Williams, J.A. Chem. Soc, 93, 641 (1971).

15. M.R. Patterson Jr. and G.H. Wahl Jr., J. Chem. Edu., 49, 790 (1972).

16. R.V. Ammon and R.D. Fischer, Angew Chem., 1 ., 675 (1972).

17. W.D. Horrocks Jr., and J.P. Sipe, J. Am. Chem. Soc, 93, 6800 (1971).

18. R.I. Reed and J.M. Wilson, J. Chem. Soc(C), 5949(1963).

19. S. Natrajan, V.V.S. Murti and T.R. Sheshadri, Ind. J. Chem, 7, 751 (1969).

: 25 :

Sterols : The sterols are compounds containing the perhydro-

cyclopentenophenanthrene nucleus (l). The name 'sterol*

was originally given to solid alcohols obtained from the non

saponifiable portions of lipid extracts of the tissue.

(I) (II)

The general name 'Steroid' was introduced to cover all

compounds with the sterol-like Skeleton (l). All the steroids

on selenium dehydrogenation ylLeld among products Diel' hydro­

carbon (II). A Steroid, may, therefore be defined as any

compound which yields Diel's hydrocarbon on selinium dehydro­

genation. They include a wide range of naturally occuring

compounds, among which are the sterol proper, the bile acids,

the sex hormones, the adrenocortical hormones, the cardiac

glycosides, the sapogenins, some alkaloids and other minor

groups. In plant they are said to have no known function al­

though they have profound importance in animal metabolism, as

hormones, co-enzymes, bile acids and pro-vitamin D etc. Certaj

animal steroids have been shown to influence plant growth

strongly.

: 26 :

Steroids of ergosterol (III) and zymosterol (IV) are

known in yeast, fungi and algae, but their presence have

hardly been established in higher plants. Others occur

(III) (IV)

mainly in lower plants but also appear occasionally in higher

plants, e,g. fucosterol (V) the main steroid of many brown

algae was also detected in the coconut. ^-Sitosterol (VI),

stigmasterol (VII) and campesterol (VIII) are probably ubi­

quitous in occurence in higher plants. A less common plant

sterol is a-spinasterol (IX), an isomer of stigmasterol found

: 27

(VII) (VIII)

(IX)

in Spinach, Alfalfa and Senega roots.

There are a variety of steroids, it appears difficult at

present to draw any definite conclusions with regard to the

taxonomic distribution of the various sterols.

^ncmmn

Flavonoids from the galls of Quercus infectorla Oliv

(Faqaceae) ;

The family Fagaceae consists of six genera and six

hundred species mostly to temperate and subtropical regions

of the norther hemisphere.

Quercus infectoria usually known as Mazoo^yields

the Oak galls, used widely in dyeing and tanning. These

galls which arise as excrescences on the young twigs are

caused by the deposition of egg by a small hymenopterous

insect, Adleria gallae-tinctoriae Olivier, The galls are

known in trade as Aleppo gall, Mecca gall, Turkey gall,

Levant gall, Snyrna gall, Syrian gall. This plant is given

in acute ameobiasis and also given in Kidney pains .

The galls contains tannic acid, gallic acid, ellagic

acid, starch, sugars and essential oils.

The present discussion deals with the study of the

flavonoidic constituents of Quercus infectoria.

The galls of Quercus infectoria were procurred from

Dawakhana, Tibbiya College, AMU, Aligarh. The plant is

first refluxed with petrol and then with benzene and alcohoJ

The petrol and benzene fractions were not giving positive

flavonoidic colour tests and hence discarded. The alcohol

part, after purification with column chromatography, yieldec

: 29 :

three fractions on silica gel TLC in solvent system

benzene : pyridine : formic acid (36:9:5). They were

named as QI-I, QI-II and QI-III. QI-I was separated by

thinlayer chromatography in the aforesaid solvent as a

single entity and its structure was confirmed by TLC and

spectroscopic techniques. Further studies for QI-2 and

QI-3a*« under progress for their stucture elucidation.

(QI-1)

1-4*.11-^'.1-5'.II-5 Tetrahvdroxv-I-7.II-7-di-O-methvl

[l-3'~II-8l blflavone :

Rx vlaue, fluorescence in UV light, mass and H-NMR

spectra of the methylether (QI-IM) were found identical

in all respects with those of authentic sample of amento-

flavone hexamethylether .

The mass spectrum of QI acetate QI-IA (m/e 734, M"*")

indicated it to be a dimethpxy tetraacetoxy amentoflavone.

The NMR data of QI-IA and other members of amentoflavone

series are given in Table-

The dimethyl ether, QI-IA is assigned the structure (I)

by comparision of the H-NMR spectrum of its acetate (QI-IA)

with the spectra of acetates of Sequoiaflavone and II-7-0-

methyl amentoflavone. The proton signals of I-A and II-A

*J. Chem. Soc, Perkin I 553 (1981).

(0 u

v> c o •p o a,

o «• +»

U

x: o

hx 7 M H

•» fv. 1

H

1 1 M M

• M

T7 M M

M

• « Vk

coco 1 1

M M M

s •

f -• k

00 ^~N C M S

• O > 0 ^ ^

I T ) ' * ! « • O

t ^ t^v_^

• k

« O N ^ - N

oooac • • o tw h-v-^

«0<-s

cox • C J

ro^- '

o O

• «o

«k

- O ^ v

o x • <o ( v . ^ ^

?S5'x • • >o

N t ^ ^ ^

• k

( N C D ' - ^ >o <o X • • o tv. t ^ ^ x

o ^ o x •CM C0>—'

"^ o

• t ^

» lO "* •

o

CM O * - " . l O - ^ X • • <o

t ^ t*-v>x

• k

• ^ l O ' - s O ^ X • • >o h- O v ^

O O ^ X • ' C M

CO r o " ' ^

CO M

• <o

• k

00 "-N N X

• «o r>.v^

Q O ^ i n lO X

• * <o t- N > - ^

CMCO'-x C M N X

• • \ 0 <J t ^ ^ - ^

/"^ h- T3 "* • • X

0 0 CM

r»-o

• h-

• k

C M - - ^ C M X

• o vO^-^

^ 00 lO i n

• • N r-

• h-'-r CM CM

• • «o o

C M ^ - ^ C M X

•CM rov^

-* CM

• o

«k

O ^ ^ v i n x • o t ^ v ^

"1 00 i n iD

• • t^ r-

CM "^ CM CM

• • »o o

C O ' - ^

' ^ X •CM

co^^

h-M

• <o

«h

^ ^ M X

• o >o^-^

M O ^ N i n lO X

• • o h-r*-v-'

M l O ' - ^ O t ^ X

• * <o O O f ^ v ^

(0 t ^ »

'.S C O ' ^ - '

r-M

• o «

•^^-^ M X

• O O ^ - '

0> CO^-N

i D i n x • • ^ N N - - ^

CO t ^ - -> O f ^ X

• • >o Q O h - > - ^

(A CO * ' t X

• O J co^-^

in

en I

o

CM I

in I

CM I

M

I

I

00 I

T3 C 3 O a s o o

• X CM CM

•o CM • l O X

•CM CM'w

M u>

• X

co-o • X

CO^-'

• X co*-^

I I 10 (0 M+> -* c (0 « tt

o • <a

c r c Q» 4) O U w > «o

"O c

• CM

M CM

• CO

h-

o •

w

CM CM

• CO

CM CM

• CO

r>-o . • CM

h-O

• CM

inx • C M

OXJ in *

• X C M ^ —

cr CM * O X

• C M C M ^ - '

in w CM •>

• X CO'*-'

00 T3 M •

• X co»>^

0 0 - O N •

• X CM^^

M 4) >^C

J3 O +> > 0) (0 S - H I ^

t^ c I «

M E M (0

T3 N •> i f i X

• C M C M ' - '

inx • C M

C M ^ —

00 » • X

CMv^

M U>

• X CO-"-"

O t3 CO *

• X 00^-^

M T 3 CM •>

• X C O " ^

I (0 I M (0

U> -P 3 0) a+> ^ I « (Qoa-p U I (0

o a> ^ T3 C 4» O O O

O4 > (0

o CM

in w CM •

• X co>>.

O-O CM *

• X COv-'

CO T3

• X CM'

O X • C M

C M v ^

i n T> 00 *

• X C M ^ - *

cr 00 . o x

• C M

• X CO^-'

M T 3 <o •>

• X CM CM

«0 TJ 00 .»

• X C M ^ - '

T3 cr

X X

- H O

s • X

CM CM

00 -O in *

• X C M ^ - '

T3 O*

X X CM 0 0 0 0

CM CM CM CM

I

I •H T3 I

f -I

M

I C 0)

e (0 9>

C o > (0

M JC *+»

- 0) M ^r E M H I I o

M O + »

• X

CM TJ CM *

• X C O ^ ^

+> +> •H nj a+» o a>

T3 O (0 (0 •H M

o u CO +»

O w CM *

• X CO-"-^

CM •© CM •>

• X

CO T3

• X 01 v ^

« c <v o+> > «J 10 +>

M «> •4-1 U 10 (0

(0 M

in w CM *

• X C0>-^

? • X

CO ^ w

CM X> CM *

• X CO ^-^

I O-P

s (0

«> c

M x: > «+* <o

t ^ 4) M

M I O

•o I

I

T3

8x • C M

in * • X

C M v ^

TJ cr X X

CM 0 0

0 0 • •

CM CM

in w CM *

• X ro^-'

M T 3

• X co^-'

M T 3 CM »

• X CO'w

I M I a

: 31 :

rings are also comparable with those of similarly

constituted I-A and II-A rings of acetate of (a) Podo-

carpus flavone B, (b) 1-4', II-7-di-methyl amentoflavone,

(c) Sciadopitsin and (d) Kayaflavone,

The acetate of QI-1 was found identical in all respects

with that of 1-4',II-4«,1-5,11-5, tetraacetoxy I-7,II-7-di-

0-methyl amentoflavone (l; •

(I)

QI-1 was, therefore, assigned the structure 1-4*,

II-4',I-5,II-5-tetrahydroxy-I-7,II-7-di-0-methyl amento-

flavone (I),

^J.C.S. Perkin-I (London), 553-559 (1981).

: 32 :

Extraction of Chemical constituents from the leaves of

Siteria italica (Graminae)

Dried and powdered leaves (2 kg) were extracted

successively with petroleum ether (60-80°) and benzene.

The combined extracts were concentrated first at atmos­

pheric pressure and then under reduced pressure.

Petroleum Ether Extract :

The greenish viscous mass (55 g) was taken in ether,

treated with aqueous solution of potassium hydroxide (15%),

then divided into alkali soluble and alkali-insoluble

(neutral) parts. The alkalisoluble portion was acidified

with dilute hydrochloric acid and then extracted with ether.

The ethereal solution was dried over anhydrous sodium

sulphate. The residue (3,0 g) on removal of ether formed

the alkali soluble part. The alkali-insoluble part was

saponified and extracted with ether. The ethereal solution

after drying over anhydrous sodium sulphate and on removal

of ether, form the neutral part (.25 g).

Neutral Part : The neutral part (.25 g) after saponification

was taken in petroleum ether and subjected to chromatographic

purification over silica gel and the following two major

products were obtained GI and GIV.

: 33 :

GIV

Benzene and chloroform (1:1) afforded crystalline

compound GIV, having m.p. 119-121°C, [a]J^-53.48(CHCl3).

It gave positive Libermann Burchard and respond to tetra-

nitromethane colour testiS. Infrared spectrum revealed the

presence of 3340, 1055cm~^(0H) > 1655, 840cm"-^(C=C) j 1460,

1375cm (C-Me2) groups. The H-NMR spectrum indicated

signals at d CDCI3 0.70, 0.80, 0.88, 1.02(^3 protons);

3.56(3a, hydroxyl) and 5.36 (IH, Vinyl proton). Spectral

data and elemental analysis (C2QH40O) suggested it to be

p-sitosterol. Its acetate melted at 112-116°C; V ""•'° max

2930, 2850, 1730, 1660, 1460, 1375, 1260 and 960cm"-^,

Further derivatization led to the preparation of benzoate,

.0^ r_Tl7 ^ C.0O m .p. 142-144°C, [a]j'-7.52".

For final confirmation the analysis of this mixture

was performed by combined gas chromatography (spectrum) -

mass spectrometry (GC-MS) on a Pye model 104 gas chromato­

graphy coupled with an AEI model MS 9 mass spectrometer

through a silicone rubber membrane separator. The sterols

were separated as their trimethyl silyl ether using a glass

column (2.5m x 4mm) packed with 1% Dexil 300 GC on 100-120

mesh diatomite. Coat 260* 0 with helium as a carrier gas.

The trimethyl silyl ethers were found to contain five

phytosterols.

The TMS ether of cholesterol, campesterol, stigmastero]

T R A » ; S ' ' - ' ' ' T T ^ ^ ' C • " r\)

>• "n

rn 5

7^ r? O

> fN

t-"!

JS'2_

' If;-)-). . , l . ; L . _ 4 . . , — . ! • . . ;- iHE-iirhi

1

^

rSl ...-_:.

r^ • - )

-t- -

-tlZl .. L . . -

t n

i--:!-::

::x:: • : " •

. - i .

<-> ._C> ' ^

-" -'--!_

t

'

C G I im^^^^'^mi^

;> r-

1 • I f

o

• ' • • M:-u:-; l4- i- . !_--. i - . , . : . ; ^ . l . . - _ ^ , . : . _ L t _ i ^ . ^ j . ; ^ • ^ ^ p . ! ^iiiii^iifiiffiiiiiiiil -Lcim.::t^d-: :-M;__-i.L„..:_.'

O XU : - i . . . . . - .;-.iJXi-i4-f-:.^xTa-ui-t4-}4 '1 ; . - j - L i i : I.'..!, J-LJ-^U i—;-!. " t i ^ r r : J"tp"C!~:^.; 'ur: i ' t ^^ l ui ''1 _i-i .• Vr^Li.nTCi.r-J / L - L : . ; (..'.Lr_L;.: , ! 1 .11 .1 ._ i . ; _ . i 4 ! u _ ' £ : „ : . i . i - i - i .LuJ

:;;rhr-:i-:;tiri^-i"" 1—

. - ^ . • . ^ • . j j j . .

: ,.:.. . . . . . . . . . . . . . . . . . - . . . . ^ . .-1 i • : . . . : - . .1 4 ! - _

•JE:E:.L:.:AHri-:riHH • - > i

• • i -

!-

c j -

: !;d:pt

TT! --11'

t.l.- ; . •_.-i„i.L-.-J-ul-;JJLLli.!-L| I i ' »-!. _,_'--i.j L4_' .'_ ^ i . j . . v : j .SvL i , - j - : . . -LJ.. . ;J. ; .L^.-^ j . l . i . jXLt- l .-rl-T-LtJ--- I ^4 ; ! . . . IJ .^L . Ij.'-^ . :.ri L l.i^

:r:a-zn.;q---;? .ri:r

l - l . : . L l . . i . ^ . , , . _ . _ : . 1 !_ _ L t J - l - .

:-x|;:;:r4algi±t;ilizrii^:li^^

i!±Ll±tt±ttt.tL ' I ; ;-rH-}i--

I ~

mmm^^ mm .;-i-4-j-^-w4-4-ff-i+

m, v^

. ; . ,LL^:: l Emmmm •-I.U

O

ffi-->

fHT - ;

_ , U . . L M .

i t ! •mm: B LU-U t±th!±i r r I : ..ii r i i Ml tti4±

vi:;::; trrrl i 'T.'cti" i. _Li;c :-:-LLLL: lixr lit t rri.;^!: i_r • .^Li. .-L.i . iTTi-U.-: i ._;-^-U L U . 1 . 1 . 1 . ; i T ! -

.1.1.4.. U a i - U . r ^ - ' ^ LL. ^ , , . . . . . a . :,. . . . 11 ; 4 -, i . <...-l^..ui i.H-i_L :t"

%

•••''• ^ . . .

100-

9 OH

80H

70-

cc

8

rA OEXSL 300 GC WATOMTECQ

260'C

< I/)

Si

foo-t

9i

^

AO 80 120 320 360 1 —

400 440 T " — r

480 300

: 34 :

and p-sitosterol gave molecular ion at m/e 458(22v6?li),

472(13.8?i), 480(26.23^) and 482(29.8?^) respectively.

The characteristic peak at m/e 129 of ^ 3p-tri-

methyl silyloxy steroid for all sterols. The peak at

m/e 129 has been identified as the fragment originating

from the cleavage of ring A along with the TMS moiety.

(CH3^ i-O

^ " 2

*(CH3)3-Si^J^

m /e 129

Similarly, the other characteristic fragmentation from

5 *

3p-trimethyl silyloxy steroid as reported by Brook

was series of ions from M-129. These ions were also promi­

nent at m/e 329(88.95^), 343(509^), 355(13.2?^), 357(1009^)

in the mass spectra of cholesterol, campesterol, stigma-

sterol and ^-sitosterol (spectrum) trimethyl silyloxy

derivatives respectively.

The structural features which distinguished each of

there sterols are the side chain of cholesterol contain

« Rodd's Chemistry of Carbon Compounds' Ed. by S. Coffen 1970, IID, p-1.

>-•«->

•H

+> C 0) •o M

'^ M 0)

• P U) 0) ^ o JZ

o

<N

UJ - I

<0

+> a> e •H H +>

« JZ •P

M

w iH O

0) +> to

<4-i

o (0

+» (0 •o fH <0 H +> U «

a (0

lA «) (0

Q>

s

•H

o a «» (0 s

(0

3

O

(0

3 U

a>

o

s .c>

CO 04 • CO

CM •

00-H O I COS

• 00

00 00

oco CO iO/->00 «H O • I too

•HC0O4 rHCO

co»n ^ - H

' ^ I o + 1 S^S <^^-x > O C M • •

• o •

^ s <~\ 00 •

>o CM ^ H CM CO

N _ X % . ^

COCO

<^ If)

lO i n CM • ^ CO

O (H M <P « 6 •P -H <o a « M 0) a o 6 " flj CM

; j o

.H O h 0) +> lA (0

1. ^ • P

w

M 0)

s M-H o a

a> -• CM

O

--1 M O 0) M S 4) -H -p a (0 M 0)

o o •p 1 -ri

w ^ 1 CM

00. o

O • • in

00 00 O C M CO »

^ C M

c o ^ • CO

•H » CO Ok v-'CM CM^H 00 I ' -^ C O S i O

lO c o i n

'CO O C O f H ^ - ' ^ C M CO CO •• 00 » • co--^ o

•><o • in • UJ H i n I I - H O

0 0 ' t S • CO'-^

CM • • H v-^iO • t^ ^ 0 0 in I ^

• O k i n + I in

3 S C M

in i n N " * COCM •^COCM

CO (U

^ iQ O

in ' t

X N CM

O

CO « •H W

o f* -"T

I 00 CM

o

l ^ C O v ^ •»—\

i n 00 CM

o - ^ CO • i n r-{

incov^ rH •CO

I 0> r-{ 2 C M C M

< ' - N O O O

o^ • • O ^HCO

in o> in ooh- in •^COCM

CO

•H W

o

o CM O

00 CM in 00 CON •^ COCM

CO

s.

8 o

CM

o

e 3

-p o a> a u>

0)

c o

• H C7> <U M

U • H - P U> O

c (0

-P o

-p

(0

-a 0)

TJ

o o 0)

u

u (0 in o CM •o c (0

c m a> $ -p 0)

X)

(A <u tn 0) (0 S

c o

: 36 :

CgH,y chain, campesterol has a C^H,^ chain, stigmasterol

has a C,QH,O chain due to the presence of double bond

at carbon 22, P-sitosterol has a C,QH2Q side chain. The

peak at 255, 275 were due to the loss of TMS and side

chain moiety from the parent compound of cholesterol, cam­

pesterol, stigmasterol and p-sitosterol. The two different

ion peaks at 3434 and 386 were present in the unidentified

substance, which was mixed with ^-sitosterol and was very

small in amount*

€xfienmenMi

: 37 :

Methvlatlon (QI-l)

QI-1 (250 mg), anhydrous potassium carbonate (6 mg),

dlmethylsulphate (2 ml) and dry acetone (500 ml) was

refluxed on a water bath for 10-12 hrs. A small portion

of the reaction mixture was taken out in a test tube and

tested for ale. FeCl^ reaction. Refluxing continued until

it gave a negative ale. FeCi^ test. It was then filtered

and the residue washed several times with hot acetone.

The filterate and washings "were combined and evaporated to

dryness. The yellow residue washed 2-3 times with petroleum

ether and then taken up in chloroform (100 ml) into a

seperatory funnel and washed several times with water.

The methylated product (10 mg) on TLC examination was found

to be hexamethylether of amentoflavone. It crystallized

from chloroform - methanol (55 mg) m.p. 227°C.

1-4'.II-4'. 1-5.II-5.1-7.II-7 Hexa-0-methyl[l-3-II-8l

biflavone (QI-IM)

^H-NMR (CDCI3) : Values on Scale :

3.66(d, IH, H-I-6); 3.52(d, IH, H-I-8); 3.48(s, IH,

H-II-3)j 3.40(s, IH, H-I-3); 3.34(s, IH, H-II-6); 3.28(s,

2H, H-II-3MI-5); 3.18(s, IH, H-I-5'); 2.92(s, 2H,H-II-2«,

II-6'); 2.82(s, IH, H-I-2'); 6.24(s,6H,20Me); 6.60(s, 3H,

OMe); 6.10(s,3H,0Me); 6.06(s,3H,0Me); 5.94(s,3H,0Me).

;

: 38 :

I-4*.II-^«.I-5.II~5,Tetra-0-methyl 1-7,II-7-diacetoxY

[l-3MI-8lblflavone (QI-IA) :

A (30 mg) was acetylated with pyridine (1 ml) and

acetic anhydride (2 ml) on a water bath for 2 hr. It

was then cooled to room temperature and poured onto crushed

ice. The separated solid was filtered washed with water

and dried. It crystallized from chloroform (22 mg),

•••H-NMR (CDCI3) : Values on T Scale :

3.41 (d, IH, H-I-6); 3.2l(d, IH, H-I-8); 3.43(s, 2H,

H-I-3, II-3); 3.25(s, IH, H-II-6); 2.97(d, 2H, H-II-3',

II-5«); 2.57(d, IH, H-I-5'); 2.50(d, 2H, H-II-2MI-6') ?

2.08(q, IH, H-I-6'); 2,02(d,lH,H-I-2'); (6.14),(6.17)*(6H,

1-7, II-7-OMe); 7.53*, "

(s, 6H,I-4MI-4'-0Ac).

1-7, II-7-OMe); 7.53*, 7,59*(6H,I-5,II-5,0Ac), 8.03, 7.77

* Alternative assignment is also possible. Figures in

parentheses represent methoxy groups.

: 39 :

Product ~ G IV

Elution of neutral part with petroleum ether j

benzene (1:1, v/v) and purification by repeated crystalli­

sation from methanol and chloroform afforded a crystalline

solid (shining needles), m.p. 119-121°C,[a]^^ -53.48(CHCl3).

It gave positive Liebermann Burchard test and yellow colour

with tetranitromethane. It gave single spot on silica gel

plate. Found : C, 84.42? , H, 12.005 , Calculated for C29H^80:

C, 84,4051 , H, 11.725^. Its infrared spectrum showed the

peaks at \ ^^3340, 105bcm"-'-(0H); 1655cm~-^(C=C); 840cm~-

(terminal methylene) and 1460, 1375cra~"^(C-Me2). The nmr

spectrum (CDCI3) indicated signals at d 0.70, 0.80, 0.88, 1.02

(CHo protons);:3.56(3a, hydroxyl) and 5,36(1H, vinyl proton).

It was found to be a sterol. A portion of the product

was converted into following derivatives.

(a) Acetate : The above product (100 mg) was treated with

acetic anhydride (2 ml) and pyridine (0.2 ml) and allowed to

stand overnight at room temperature, then heated on a steam

bath for six hours. The solid product obtained was crystalli­

sed from methanol and chloroform as colourless flakes (50 mg)

m.p. 112-116°C [ajj* - 48.56°, i) max^^^^' ^^» ^'^^^* ^^^»

1460, 1380, 1260, 960cm"-'-.

(b) Benzoate : The sterol (45 mg) was treated with benzoyl

chloride (l ml) and pyridine (O.l ml). The mixture was

: 40 :

allowed to stand overnight at room temperature and then

heated for about six hours on a steam bath. The solid

derivative obtained was filtered off, washed with aqueous

solution of potassium hydroxide {2%) and water, then finally

crystallised from methanol, m.p. 143-145°C (25 mg),,

[a]^^ . 7.52°.