INTRODUCTION: IRRIDOIDS

PRESENTED BY : AYESHA BIBIM.phil student

2PRESENTED TO: Respected teacher: Dr.FirdosContents:IntroductionHow derived?StructureOccurrenceClassificationBiosynthesisExtractionSpectral analysis by Ms/MsCharecteristicsBiological propertiesObjectives

3 IRIDOIDS

INTRODUCTION: IRIDOIDSClass of secondary metabolites .Monoterpenes biosynthesized from isoprene.Intermediates in the biosynthesis of alkaloids.More than 2500 Iridoids compounds isolated.Found in nature as Secroiridoids.

Ref. http://en.wikipedia.org/wiki/Iridoid http://dx.doi.org/10.5772/55784

IRIDOIDS : HOW DERIVED?Compounds like iridomyrmecine, iridolacotne and iridoidal involved in Insects defensive mechanism isolated from the ant Iridomirmex genus, for which iridoids are named.

iridomyrmecineINTRODUCTION: IRIDOIDSClass of secondary metabolites .Monoterpenes biosynthesized from isoprene.Intermediates in the biosynthesis of alkaloids.More than 2500 Iridoids compounds isolated.Found in nature as Secroiridoids.

Ref. http://en.wikipedia.org/wiki/Iridoid http://dx.doi.org/10.5772/55784

Iridoid was first isolated in the latter period of the nineteenth century.

However, the basic skeleton of iridoid was not identified until 1958.

O. Halpern and H. Schmid proposed what iridoid looks like while investigating Plumieride structure.

STRUCTURE: IRIDOIDSMethylcyclopentan-[C]-Pyran SkeletonIridane + Six member Oxygen ringIridane skeleton cis-2-oxa-bicyclo-[4,3,0]-nonaneIridane: Cyclopentane ringGenerally consist of 10, 9, or rarely 8 carbon atoms.C11 is more frequently missing than C10. May have more or multiple variation up to polycyclicStructures. Ref: http://dx.doi.org/10.5772/55784

GENERAL IRIDOID SKELETON

IRRIDOIDS : OCCURRENCEInsects s: Ants

Plants: Dicotyledon: Angiosperm

Plants family: Dipsacales, Genitianales, Scrophulariales, Lamiales Aucubin and Catalpol --- Most common iridoids in the plant kingdomRef: http://www.slideshare.net/priyankagoswami/terpenoid-iridoid?related=1IRIDOIDS - CLASSIFICATIONIridoids 10 carbon atoms bicyclica. Glycosides iridoids (Accubin, catapol)b. Non- glycosides iridoids (alkaloids, skytantine)

2.SecoiridoidsOxidative cleavage at 7,8 bond of cylopentanea. Glycosidic secoiridoidsb. Non-glycosidic secoiridoids

Glycosides glycosidic linkage between -OH group on anomeric carbon of D-glucose and the-OH in the 1-position of aglycone

Journal of the Brazilian Chemical Society PrintversionISSN 0103-5053 J. Braz. Chem. Soc.vol.12no.2So PauloMar./Apr.2001 .http://dx.doi.org/10.1590/S0103-50532001000200004

Different classes of iridoids1.Iridoids 2.SecoiridoidIRIDOIDS: BIOSYNTHESISIridoids are formed from geraniol by the mevalonate pathway.

Geraniol is the major ingredient in rose essential oils (40-60%), and smells rose-like odor. http://iridoid.org/?page_id=42

The iridoid ring synthesized by the enzyme iridoids synthase .Iridoid synthase uses 10-Oxogeranial as a substrate.Two-step mechanism,Reduction step NADPH-dependent

Cyclization step that occurs through either a Diels-Alder reaction or an intramolecular Michael addition

Total bio synthesis of iridoids: Secologanin17Extraction: IridoidsExtractionInitial separationFractionationPurificationDetectionDetection sprayPolar solvents, alcohols of diff. concentration for extraction i.re- dissolving extraction residue in H2Oii. Re-extracting with immiscible solvent of increasing polarityChromatography (on alumina ,charcoal) Porous polymers with polar eluents and by polar RP HPLCTLC,HPLCTrim and Hill Color reagent (dilute sol. CuSO4 and HClVanillin H2SO4, hot HCl

Spectral AnalysisIn MS, formate adduct ion [M+HCOO]- diagnostic ion having methyl ester, lactone, or carboxyl group at their C-4 positions.

Neutral losses of H2O, CO2, CH3OH, CH3COOH, and a glucosidic unit helps to identify functional substituent are in the MS/MS spectra..

Structural information of basic skeleton and its substituents by 1,4F, 2,6F,and 2,7F fragments.

By the he relative abundances of the fragment ions 1,4F and 2,7F,7,8-cyclopentene-type and cyclopentane-type IGs, can be differentiated

RAPID COMMUNICATIONS IN MASS SPECTROMETRY Rapid Common. Mass Spectrom. 2008; 22: 19411954 Published online in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/rcm.3579Characteristics of iridoidsLeticia J. El-Naggar , Jack L. Beal J. Nat. Prod., 1980, 43 (6), pp 649707 DOI: 10.1021/np50012a001 Publication Date: November 1980Iridoids are also refer as Pseudoindicans .

Bitter taste.

Easily dissolve in H2O.

Some iridoids upon hydrolysis develop Blue coloration.

Delicate show great Instability , iridoids plants species darkens soon after collecting.

Biological PropertiesShows wide spectrum of Biological ActivityDefensive Function in antsAnti- InflammatoryAnti bacterialAnti FungalAnti TumoralAnti OxidativeAnti Protozoal

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