PHARMACOGNOSY I (6)
Page 1: Introduction
Pharmacognosy I PHAR301
Lecturer: Dr. Beste Atli
Topic: Flavonoid Glycosides
Page 2: General Characteristics of Flavonoids
Solubility
Flavonoid glycosides:
Usually soluble in water or water-alcohol mixtures.
Insoluble in organic solvents.
Aglycones:
Soluble in non-polar solvents (organic solvents).
Physical Properties
Mostly crystallized compounds.
In alkaline medium, they give a yellow solution.
Adding an acid to the yellow solution causes the color to disappear.
Page 3: Extraction of Flavonoids
Extraction Methods
Different methods are applied if flavonoids and flavonoid glycosides are both present.
Flavonoid glycosides are extracted using:
Acetone
Ethanol
Methanol (in aqueous solutions).
Application of Liquid-Liquid Extraction
Uses of various solvents:
Petroleum ether: For chlorophyll and pigments.
Diethyl ether or CHCl3: For aglycones.
EtOAc: For glycosides.
Page 4: Concentrated Extract Processing
Steps In Extraction Procedure
Concentrated extracts (from acetone, ethanol, or methanol-aqueous solutions) retain:
Pigments, lipids, and other residues.
Sequential treatment with:
CHCl3
Results in a residue (free flavonoids).
EtOAc
This yields a fraction containing glycosides (very polar glycosides and free saccharides).
Page 5: Types of Flavonoids
Various Categories
Isoflavones
Flavanones
Dihydroflavonols
Methylated flavone/flavonol derivatives
Flavones
Flavonols
Biflavonoids
Aurones
Chalcones
Boiling water extracts yield flavonediols and catechols.
Page 6: Chromatographic Techniques
Separation and Cleaning Methods
Various chromatographic techniques used:
Polyamide
Sephadex
Silica Gel
Alumina (AlO2)
HPLC (High-Performance Liquid Chromatography)
Page 7: Determination Reactions of Glycosides
Chromatographic Methods
Provide fluorescence under UV light.
In alkaline medium, they yield a yellow color.
Direct Detection
Aurones and chalcones can be detected directly with ammonia vapors, resulting in:
Orange or red colors.
Alcoholic potash darkens the yellow color in alkaline medium.
Page 8: Color Reagents for Flavonoids
Color Reaction Indicators
1% AlCl3/EtOH: Flavone shows a yellow reaction.
1% PbOAc: Flavonols yield an orange color.
1% FeCl3: Di-hydro derivatives give green color; polyhydroxy derivatives yield blue.
Potassium Borohydride: Flavanones yield violet, while flavonoids present brown and green colors.
Page 9: Classical Color Reactions
Specific Tests
Cyanidin reaction: Pure aqueous-ethanol extracts plus HCl and Mg/Zn powder produce:
Flavones → Orange
Flavonols → Red
Flavanones → Purple
Aurones → Yellow-orange
Chalcones → Colorless.
Page 10: Alkaline Color Reactions
Color Changes in Reactions
Flavones in alkaline medium turn yellow.
H2SO4 with flavones yields a yellow reaction, and SbCl5/CCl4 produces a red-violet color.
Dil. H2SO4 with dissolved boric acid results in bright yellow; FeCl3 gives green for dihydroxy compounds and blue for polyhydroxy compounds.
Page 11: Identification Tests for Anthocyanins
Chemical Tests
Uses:
Diluted HCl: Produces red color.
NaOH: Produces blue color.
Lead Acetate: Yields green color.
A cooled-down mixture of diluted HCl and amyl alcohol produces a wine-red color for cyanidin R.
Page 12: Quantitative Determination
Colorimeter Usage
Setup: % transmission read at 740nm.
HPLC: Sample carrier filter set to red for accurate readings.
Page 13: Biological Activities of Flavonoids
Vitamin P Activity
Structures with hydroxyl-groups at positions 3',4 reduce capillary permeability, increasing capillary resistance in arterial walls.
Used in circulatory disorders like arteriosclerosis, varicose veins, diabetes, and geriatrics.
Sources: orange, lemon, rose hip, red pepper.
Page 14: Diuretic and Diaphoretic Activities
Flavonoid Sources
Flavonoids like luteolin, apigenin, rutin, kaempferol, quercetin found in:
Chamomillae flos
Tiliae flos
Helichrysi flos
Equiseti herba
Betulae folium
Viburni cortex
Noted for their use in reducing gallstones due to diuretic effect.
Page 15: Antispasmodic Properties
Antispasmodic activities found in:
Chamomillae flos
Tiliae folium
Rutae herba
Crataegi flos
Viburni cortex
Liquiritiae radix
Page 16: Quercetin and Rutin Structure
Chemical Composition
Showcase of the chemical structure:
Quercetin
Rutin
Page 17: Anti-inflammatory Properties
Key Players in Anti-inflammatory Activities
Apigenin
Hypolaetin-8-glucuroside
Page 18: Antibacterial, Antifungal, Antiviral Properties
Notable Compounds
Identified compounds include:
Rutin
Quercetin
Phytoalexins (differing structures).
Page 19: Antihistaminic Effects
Scutellaria baicalensis noted for antihistaminic properties.
Page 20: Estrogenic/Antiestrogenic Effects
Isoflavonoids observed in:
Glycine max (soybean)
Lepidium capitatum
Trifolium repens
Page 21: Insecticide Effects
Notable Compounds
Rotenoids featuring tetrahydrofurane-ring obtained from Derris elliptica.
Page 22: Cardiovascular Benefits
Effects
Enhancements in the contractions of the heart, acting as a coronary vasodilator and antiarrhythmic from compounds like Crataegus monogyna.
Page 23: Purgative Uses
Notable Plant
Prunus japonica, but with a caution for unauthorized use.
Page 24: Hepatoprotective Effects
Key Component
Flavonolignans (a mix of flavonoid and lignan) found in Silybum marianum.
Page 25: Dyes from Anthocyanins
Industrial Uses
Anthocyanins are used as dye sources from:
Red cabbage
Grape
Elderberry
Red radish
Blackcurrant
Black carrot
Page 26: Therapeutic Applications of Flavonoids
Treatments
Primarily useful for:
Capillary and venous disorders
Leg pain
Weakness
Edema
Muscle cramps
Capillary fragility
Skin and mucosa disorders
Acute hemorrhoids.
Page 27: Specific Therapeutic Uses
Further Applications
Treatment for menorrhagia due to IUD, impaired retinal circulation, menopause symptoms with:
Diosmin & hesperidin (Daflon®)
Rutin (Venoruton®)
Page 28: Flavonoid-bearing Plants
Ginkgo Biloba
Common Name: Ginkgo, Maidenhair tree
Family: Ginkgoaceae
Drug Name: Ginkgo folium (Ph.E)
Page 29: Flavonoid Compounds in Ginkgo Biloba
Key Ingredients
Bilobalide (sesquiterpene)
Ginkgolides (diterpene)
Quercetin and kaempferol derivatives (flavonoids)
Amentoflavon and ginkgetin (biflavones)
Page 30: Medical Benefits
Vasodilator Effects
Employed in treating:
Amnesia
Dementia
Forgetfulness
Hearing loss (deafness)
Tinnitus
Vertigo disorders.
Page 31: Tebokan® Usage
Medical Application
Utilized for treating symptoms related to:
Brain and limb perfusion disorders
Aids in memory, concentration, and functions as an anti-vertigo agent.
Contains flavonoids and terpenoids extracted from ginkgo leaves.
Page 32: Passiflora Incarnata
Plant Overview
Common Name: Purple passionflower, Maypop, Wild apricot
Family: Passifloraceae
Drug Name: Passiflorae herba
Home: South America.
Characteristics: Perennial climbing plant.
Active compounds: Vitexin, Isovitexin, Orientin, Isoorientin, Schaftoside.
Page 33: Thymus Vulgaris Overview
Plant Characteristics
Common Name: Thyme
Family: Lamiaceae
Drug Names: Thymi herba, Thymi aetheroleum (Ph.E)
Notes: Perennial aromatic Mediterranean plant with 350 species.
Page 34: Apigenin and Luteolin Derivatives
Chemical Structure Overview
Depiction of apigenin and luteolin derivatives.
Page 35: Thyme Species Overview
Known Thyme Varieties
Coridothymus capitatus (Persian-hyssop, Spanish oregano)
Thymbra spicata (Za’atar; Middle East)
Satureja thymbra (Thyme-Leaved Savory; South East Europe)
Several Origanum species including O. heracleoticum (Greek oregano) and O. smyrnaeum (Smyrna oregano).
Page 36: Thyme Species Continuation
Additional Varieties
Additional listings of thyme varieties:
Coridothymus capitatus
Thymbra spicata
Satureja thymbra
Origanum heracleoticum
Origanum smyrnaeum
Page 37: Citrus Species Overview
Citrus Characteristics
Common Name: Citrus
Family: Rutaceae
Drug Names:
Neroli aetheroleum (Ph.E.)
Aurantii dulcis aetheroleum (Ph.E.)
Limonis aetheroleum (Ph.E.)
Native to the Far East (China, India), cultivated in subtropics.
Page 38: Citrus Flavonoids
Chemical Structure Overview
Depiction of the chemical structure of various flavonoids including rutin, diosmin, naringin, and hesperidin.
Page 39: Silybum Marianum Overview
Plant Description
Common Name: Saint Mary's Thistle, Milk Thistle
Family: Asteraceae
Drug Name: Cardui mariae fructus
Significance: Named Marian in association with the Virgin Mary.
Page 40: Active Compounds in Silybum Marianum
Key Component
The active ingredient responsible for therapeutic effects: Silymarin (a mixture of flavonolignans) makes up 1.5%-3% of the drug composition.
Page 41: Achillea Millefolium Overview
Plant Characteristics
Common Name: Yarrow
Family: Asteraceae
Drug Name: Millefolii herba (Ph.E.)
Noted features: Dumb flowers, white/pink blooms, thin piece leaves; approximately 40 species.
Page 42: Achillea Millefolium Uses
Therapeutic Properties
Contains essential oil, sesquiterpene lactones, flavones, and flavonols with noted properties such as:
Spasmolytic
Choleretic
Anti-inflammatory
Emmenagogue
Treatment for gastrointestinal disorders and menstrual pain.
Page 43: Equisetum Arvense Overview
Description
Common Name: Field horsetail
Family: Equisetaceae
Drug Name: Equiseti rhizom
Habitat: Found in Europe and North America, characterized by two types of plants: separate fertile (productive) and sterile (non-productive) individuals.
Page 44: Equisetum Anatomy
Morphological Features
Distinguished by:
Ashy-gray, unbranched shoots tipped with spore-producing strobili.
Presence of whorls of 6-8 leafless branches.
Page 45: Growth Characteristics of Equisetum
Plant Size and Features
Plants reach 40-50 cm tall; green summer tail without flowers.
Fertile and sterile individuals are distinct in their morphology and functions.
Page 46: Kaempferol and Quercetin Derivatives
Chemical Structures
Showcasing the structural representations of kaempferol and quercetin derivatives.