Herbal Constituents Supportive Science for Botanical Medicine © Lisa Ganora 2008
Dec 29, 2015
Herbal Constituents
Supportive Science for Botanical Medicine© Lisa Ganora 2008
An Isolated Phytomolecule
• Isolated digitoxin is used in contemporary pharmacy
• Cardiac glycoside, extracted from Foxglove (Digitalis purpurea or D. lanata)
A Phytochemical in a MatrixThe ascorbic acid molecule is exactly the same in Oranges or Violets, but is embedded in very different chemical matrices
Functional Groups• Alcohol• Ketone• Aldehyde• Carboxylic acid • Ester• Ether• Amine• Amide• Sulfide• Sulfoxide• Methyl• Phenyl
R = any carbon backbone
Constituents: Major Categories
• Carbohydrates• Lipids• Amino acids &
derivatives• Phenolic
compounds• Terpenoids• Steroids• Alkaloids
• monosaccharides• oligosaccharides• polysaccharides• fatty acids• oils
(triacylglycerols)• waxes• alkamides
(including isobutylamides)
• sulfur compounds (Garlic)
• glucosinolates• cyanogenic
glycosides• 5-HTP• amines• enzymes
• simple phenols• phenolic acids• phenylpropanoids• coumarins• lignans• stilbenoids• xanthones• styrylpyrones• flavonoids• isoflavonoids• benzofurans• chromones• quinones• phloroglucinols
• monoterpenes• sesquiterpenes• essential oils• diterpenes• triterpenes & saponins• tetraterpenes (carotenoids)
• steroidal saponins • phytosterols• cardiac glycosides
• betalain alkaloids• diterpenoid alkaloids• indole alkaloids• isoquinoline alkaloids• methylxanthines• monoterpenoid alkaloids• peptide alkaloids• pyrrolidine alkaloids• piperidine alkaloids• pyrrolizidine alkaloids• quinoline alkaloids• quinolizidine alkaloids• tropane alkaloids
Immunomodulating Polysaccharides
• Stimulate non-specific immunity• Echinacea: glucuronoarabinoxylans
(glucuronic acid + arabinose + xylose) & arabinorhamnogalactans (arabinose + rhamnose + galactose) & arabinogalactans
• Others in Eleuthero, Baptisia, Calendula, Panax ginseng• Larix (Larch) has arabinogalactans
Baptisia
Fatty Acids: Omega Series
• Tells where the double bonds are in the molecule
• Omega 6’s & Omega 9’s common in diet
• Omega 3’s come from Flax & fish oils
Alpha-linolenic acid (ALA),from Flax seed oil: Omega 3
DHA – docosahexaenoic acid,from cold-water fish oils:Omega 3
EPA, eicosapentaenoic acid,from fish oils: Omega 3
Isobutylamides
• Isobutylamides are a type of alkamide • Echinacea purpurea & E. angustifolia
have the highest concentrations• Contribute to immunomodulating effect• Stimulate phagocytosis• COX-2 inhibitors
(anti-inflammatory)
Sulfur Compounds in Garlic• Alliin (major cysteine sulfoxide in Garlic)
+• Alliinase (an enzyme in fresh, whole
Garlic or correctly dried Garlic powders) Allicin, the active antibiotic
compound• Allicin sulfides, ajoene, dithiins, etc.
Alliinase
Alliin Allicin
Flavonoids• Largest class of polyphenols: ~ 4,000 kinds• Often responsible for yellow or
red/blue/purple colors in flowers, fruits, vegetables
• Serve as antioxidants for the plants during photosynthesis
• Includes antioxidant, anti-inflammatory, cancer-preventative, & cardioprotective compounds
–OH group at position 3 with double bond between carbons 2 & 3; next to =O at position 4 on ‘C’ ring–OH group at position 5 on ‘A’ ring next to =O and –OH on ‘C’ ring
Structures responsible for antioxidant activity include:
–OH groups at positions 3’ and 4’ on ‘B’ ring
Quercetin has all three features – an excellent antioxidant
Why are Flavonoids Good Antioxidants?
B
CA
Monoterpenes & Sesquiterpenes
• Monoterpenes: 10 carbons• Sesquiterpenes: 15 carbons
1 2
3
4
56
7
8
910
Menthol Nerolidol
1
2
3
4
5
6
7
8
9
10
11
12
131415
Antiseptic Monoterpenes• Cineole (1,8-cineole or eucalyptol) is the
major constituent of Eucalyptus oil (~ 70 – 85%)*
• Antiseptic, antibacterial, expectorant• Excreted through lungs: bronchitis• α-Pinene, a minor constituent (up to
14%) is toxic in very high doses
Cineole α-Pinene
Triterpenes & Steroids• Triterpenes• Saponins
– Triterpenoid– Steroidal
• Steroids– Misc. steroids– Phytosterols– Cardiac glycosides
• ~ 4,000 different structures known
• Triterpenes have 3 x 10 = 30 carbons
• Steroids are derived from them; lose 3 carbons to end up with 27
Triterpene skeleton
Steroid skeleton
Cardiac Glycosides in Lily of the Valley
• ~ 40 different glycosides based on several different aglycones; variable
• Convallatoxin highly active, but generally no more than 10% of the amount ingested can be absorbed
• Positive inotropic effect; used for mild cardiac insufficiency
Tetraterpenes: Carotenes & Xanthophylls
• Lycopene – parent compound of carotenoids
• Carotenes – alpha-, beta-, delta- & gamma-carotenes are closely related
• Xanthophylls – carotenoids with oxygen in their structures – include lutein, neoxanthin & violaxanthin; capsanthin & capsorubin; astaxanthin
Capsaicinoids: Pungent Principles in Capsicum Annuum
• Capsaicin & relatives are oil-soluble• Powerful topical analgesics: herpetic neuralgia,
arthritis• Diaphoretic, rubefacient, antiseptic
Betalain Alkaloids• Nitrogenous pigments found only in a
few plant families, where they replace anthocyanins
• Very potent antioxidants• Anticarcinogenic
Betanidin
Pyrrolizidine Alkaloids (PAs)
Symphytine, adiester
Necine rings are metabolized into toxic pyrroles in the liver cells
Necine rings
Lycopsamine, a monoester
Isoquinoline Alkaloids in Mahonia
Berberine
• Berberine & relatives predominate• Some palmatine & jatrorrhizine• Actions similar to Goldenseal
Herbs for the Immune System
Supportive Science for Traditional Herbal Medicine© Lisa Ganora 2008
Astragalus
• Stimulates non-specific immunity
• Deep immune system tonic
• Antioxidant• Adjunct therapy for
cancer• Astragaloside III is
one of many saponins in the root
Astragaloside III
Popular Healing Herbs
Supportive Science for Traditional Herbal Medicine© Lisa Ganora 2008
Cranberry• Cranberries are rich in anthocyanins:
– Cyanidin glycosides– Delphinidin glycosides– Peonidin glycosides
• Contain glycosides of quercetin• Lignans also present• Proanthocyanidins inhibit binding of bacteria to
urinary tract epithelium• Flavonoid extracts inhibit the growth of prostate
cancer cells• Many constituents are antioxidant
Hawthorn
• Hyperin, a glycoside of quercetin, is the main flavonoid in Hawthorn
• Also contains OPC’s• Helps heart muscle to work more
efficiently, strengthens contractions, stabilizes rhythm
• Enhances the utilization of oxygen in cells
• Contains many antioxidants• Antispasmodic, anti-inflammatory
Herbal Chemistry
Bonding in Phytochemicals
Oxygen can form a double bond with carbon
Acetone
Stereochemistry of Phytochemicals
Why isomerism matters: receptor specificity
X
Receptor binding site
X
Receptor binding site
R enantiomer S enantiomer
Ring Systems
Cyclohexane ring vs. benzene ring
pH Affects Solubility: Bases
To isolate basic compounds in the lab, first the whole plant is extracted with ethyl acetate or a similar solvent
Next the extract is mixed with a water solution that has been acidified with an inorganic acid like dilute HCl
And the ionized base, being water-soluble, partitions down into the aqueous layer