Dr.S.Alexandar,M.Pharm,Ph.D, Associate Professor Vinayaka Missions College of Pharmacy, Yercaud main road, Kondappanaickanpatty, Salem, Tamilnadu, Pin:636008 Flavonoids

Chemical analysis of flavonoids. Medicinal plants and medical plant material that contain flavonoids with cardiovascular, P-vitamin and haemostatic action

FLAVONOIDSare polyphenolic compounds comprising fifteen carbons, with two aromatic rings connected by a three-carbon bridge (C6-C3-C6).

Flavan

The B ring formation is produced by a shikimate pathway

The A ring and propane fragment are formed via acetate pathway

Classification of flavonoids

Depending on the position of the linkage of the aromatic ring to the benzopyrano (chromano) moiety, this group of natural products may be divided into three classes: the true flavonoids (2-phenylbenzopyrans); the isoflavonoids (3-benzopyranes) and the neoflavonoids (2-benzopyranes)

True Flavonoids

Chromane derivatives2. Chromone derivatives - catechins (flavan-3-ols); - flavanons; - leucoanthocyanidins - flavanonols; (flavan-3,4,-diols); - flavones; - anthocyanidins - flavonols; - chalcones; - dihydrochalcones; - aurones

Anthocyanidins NamePelargonidinCyanidinDelfinidinFlavanonesNameLiquiritigeninNanringeninEriodictyolHesperetinFlavonesNameApigeninLuteolinAquacetinDiosmetin

FlavonolsKaemferolQuercetinMyricetinRhamnetinIsorhamnetinNameNameChalconesButeinIsoliquiritigenin

Extraction and investigation methods of flavonoids

Ethanol and methanol are mainly used for flavonoid extraction. Spirituous extracts are evaporated to water residue, then diluted with water and treated by chloroform for lipids and lipoids (chlorophylls, carotenoids, waxes, etc.) separation. Purified water residue is treated by diethyl ether, ethyl acetate, propanol, butanol in series, getting fractions of aglycones, mono-, di-, triglycosides.

IdentificationCyanidin testTest with boric and citric acidsAn azo couplingThe reaction of alkali Concentrated sulphuric acid testThe reaction with vanillin in concentrated hedrochloric acidThe reaction of iron III chlorideThe reaction of lead acetate

Compounds Cyanidin testFeCl3lead acetateFlavanolsRed-violetYellow BrownYellow residueFlavonolsRedYellow GreenYellow residue

FlavonesOrangeYellow Red-brownYellow residue

ChalconesYellow Yellow-orange BrownYellow residue

AuronesYellowOrange-redBrownYellow residue

CatechinsYellow Colorless, changing to redFrom brown to blueYellow residue

Quantitative analysis

There are plenty of methods for flavonoid assay: gravimetry, titration, fluorimetry, polarography, photocolorimetry, but the most widespread method is spectrometry. It is based on reactions with metal ions, azo coupling, boric acid with further determination of the optical density in UV and visible regions of the spectrum at a proper wavelength.

Motherwort Herb Leonuri herba, EP Motherwort Leonurus cardiaca L., Leonurus quinquelobatus Mint family- Lamiaceae Syn.: Throw-wort, Lions Ear, Lions Tail.BAS: complex flavonoids, alkaloides (major is stachydrine),irydoides, tannins, terpenoids. Major flavonoids hyperoside, kaemferol-3-D-glucoside rutin, quercetin, isoquercetin, tannins and a small amount of essential oil. The EP requires a minimum flavonoid content for the drug of 0,2 % expressed as hyperoside and assayed by adsorbance at 425 nm

Dosage forms: infusion included Mixture antiasthmatlca Trascovi, tincture included CardioPhyt, Biovital, Gerovital, Doppelherz# Energotonic Pharmacological activity: infusion and tincture as sedative and hypotensive agent in cardiovascular neurosis, the initial stages of hypertension, cardiosclerosis, increased nervous excitability.

Hawthorn Fruit Crataegi Fructus Hawthorn Flower Crataegi Flores Hawthorn Crataegus sanguinea Pall., Family Rosaceae Rosaceae.Syn.: May, mayblossom, maythornBAS: giperoside (0,7%), C-glycosides vitexin:, rutin, dominate in the leaves. The fruits contain epicatechin, oligomers anthocyanidins, and also anthocyans, pectins, ascorbic acidPharmacological activity : Galene drugs have cardiotonic, hypotensive, sedative and antispasmodic action, reduce the excitability of the central nervous system, have tonics effect on the heart muscle, enhanced blood circulation in coronary heart and cerebrovascular, eliminate tachycardia and arrhythmia.Dosage forms : Liquid extract of the fruit included to rdiovalenum. Liquid extracts from flowers included toCardioPhyt, Biovital, Gerovital and Phytulventum

Water pepper Herb Polygoni hydropiperis Herba , Water pepper Polygonum hydropiper L.,Family Polygonacea Polygonaceae.Syn.: Smartweed, Biting persicaria, Bity tongue, Pepper plantBAS: rutin, quercetin, hiperosed, cemppherol, tannins, vitamins K and C. Raw materials containing substances such as colored phagopirin causing phagopiryzm (sensitivity to light). Pharmacological activity : hemostatic, .

Dosage forms: liquid extract

Redshank Herb Polygoni persicariae herba Redshank Polygonum persicaria L.,Family Polygonaceae. Polygonaceae.Syn.: Persicaria, Redleg, Ladys-thumb, Adams plaster

BAS: hiperosed, isoquercetin,, tetrametilquercetin. Herb containing vitamin K, tannin, flobafen free galou acid,, essential oil, pectins.

Pharmacological activity : hemostatic, a slight laxativ effect.

Dosage forms: tea, extract

MRM which contain flavonoids with P-vitamin activity P-vitamin activity means that medicine or herb strength capillaries.

Black chokeberry fruit Aroniae melanocarpae Fructus recentesBlack chokeberry Aronia melanocarpa (Michx) Elliot Rosaceae Constituents. Cyanidin and its glycosides, phenolic acids, flavonoids- rutin, quercetin, gesperidin; pectines; ascorbic acid; big amount of iodine (5-6 mcg/100g), Folic acid, riboflavin, tocopherol, carotinoids; lipids, wax, paraffin. Uses. Fresh fruits and juice are used for prevention of vitamin P insufficiency, they are useful for those with hypertension. Lipophilic substances are the part of Aromelin which has restorative action.

Pagoda tree buds Sophorae japonicae Alabastrae Pagoda tree fruit Sophorae japonicae Fructus Pagoda tree Sophora japonica Syn.: Chinese Scholar, Japanese pagoda tree.FabaceaeConstituents. Up to 20% of rutin. Uses. As the main constituent is rutin the plant is used in the treatment of circulatory diseases (Ascorutin, Vikalin, Rutes). Tincture has antiseptic properties.

Lemon peel Citri Exocarpium Lemon - Citrus limonRutaceae Constituents: flavonoids, especially neohesperidosides and rutinosides of hesperetin and naringenin (rutin, eriocitrin, neohesperidin, hesperidin) along with many other flavonoids (44 flavone glycoside were detected); essential oil (+ limonene as the principle component, citral determine the odour); carotenoids, citric acid and many other plant acids, coumarin derivatives, pectins.

Uses. Its used chiefly as an aromatic and stomachic. The efficacy of lemon flavonoids in treating varicose veins is related to their ability to reduce capillary fragility, increase integrity of the venous wall and increase the muscular tone of the vein.The raw material and its extracts are used to treat diseases of the blood vessels and lymph system, including haemorrhoids, chronic venous insufficiency, leg ulcers, nosebleeds.

Tea leaf Theae foliaTea Thea sinensis (syn. Camellia sinensis) (L.)TheaceaeConstituents: abundant flavonoids, including the apigenin derivatives isoschaftoside and vicetin-3, catechols, leucoanthicyanidins, theaflavins, condensed tannins (10-20 %), 4-gallocatechol, phenolic carboxilic acids (gallic, chlorogenic); methylxanthines (caffeine, theobromine, theophylline, adenine, xanthine); the flavour and aroma substances, some of which arise during the fermentation stage (hex-3-en-1-ol, benzyl alcohol, linalool in black tea and geraniol in grean tea); triterpenoid saponins.Uses. Owing to its caffeine content, tea serves as a stimulant, and bacause of its tannin content it can be used an anthidiarrhoeic. Polyphenols have P-vitamin and the antioxidant activity. Strong tea is given in poisonings caused by central nervous system inhibitors, alcohol, heavy metals.