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Sesterterpenes C 25 H 40

Sesterterpenes C 25 H 40. Obtained of condensation 5 IPP by head-to-tail manner; structural variations [lactones] GGPP + IPP→Sesterterpenes (Ophiobolanes) Isolated as phytotoxic principles from pathogenic fungi Isolated from marine organisms, sponges

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Sesterterpenes C 25 H 40

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  1. Sesterterpenes C25H40 Obtained of condensation 5 IPP by head-to-tail manner; structural variations [lactones] GGPP + IPP→Sesterterpenes (Ophiobolanes) Isolated as phytotoxic principles from pathogenic fungi Isolated from marine organisms, sponges Antibacterial, antifungal, antinematodal activities

  2. Triterpenes • MVA-derived • Tail to tail of 2 x FPP • 1st Isolated from shark (Squalus sp.), later from rat liver & yeast • Many seed oils rich in squalene

  3. Squalene C30H50 Different folding possibilities Cyclisation and rearrangement: Triterpenes: -Tetracyclic triterpenes -Pentacyclic triterpenes (Lupeol type, α- and ß-amyrin types) Steroids: (Sterols, bile acids, steroid hormones, steroid saponins, steroid alkaloids, cardiac glycosides, Vit. D )

  4. Lanatosterol & Cycloartenol • Oxidation, cyclyzation, alkyl migration & folding of squalene produce STEROIDS {lanosterol (animals & fungi) and cycloartenol (plants)} • Natural triterpenes & steroids OH at C3

  5. Tetracyclic and pentacyclic triterpenes Dammarane

  6. Saponins • Many triterpene have been isolated. Few of medicinal interest, mainly saponins Common Characters of SAPONINS: • Glycosides (mono- or bis-desmosides) • Produce stable froth in aqueous solution (shaking) • Surfactant effect (oil-H2O mixes) • Surfactant effect (soap-like) Latin origin: sapo=soap. Saponins-rich plants were used for cleansing e.g. soapwort (Saponaria officinalis, Caryophyllaceae), Quillaia or soapbark (Quillaja saponaria, Rosaceae) • Induce RBC haemolysis (changes wall permeability) • PPt by heavy metals e.g. Mg, Hg, Pb....

  7. Saponins cont. • Tetra- or Penta-cyclic structures • Steroidal of triterpenoidal nucleus • Toxic to cold-blooded animals (fishing, pesticides, molluscosides) • Induce RBC haemolysis (changes wall permeability) • Arrow poison (RBC haemolysis)

  8. Chemistry of Triterpenoid Saponin O = Oxygenation site

  9. Liquorice • Unpeeled rhizomes and roots of the perennial herb Glycyrriza glabra, Fabaceae • Russian liquorice peeled prior to drying, G. glabra var.glandulifera • Chinese spp. G. uralensis (Manchurian liquorice) commercially valued • Water extracted, dried by evaporation producing black solid

  10. Medicinal and Economic Applications of Liquorice • Flavouring agent (food, tobacco, beers, chewing gums) • Sweet, froth forming (saponins characters) Glycyrrhizin 50-150x ≥ sweet sugar (bitter taste mask) pharmacy • Demulcent, surfactant, expectorant, laxative • Corticosteroid-like activity, mild anti-inflammatory, mineralocorticoid activity • Rx Addison’s disease, # catalyse enzyme prevent conversion of PG & glucocorticoides into inactive metabolites (inc. PGE2, PGF2 & HC) (Cushing’s S/E)

  11. Chemical Composition 12% water extractives • 3-5% glycyrrhizic (glycyrrhizinic) acid • 1-1.5% free & glycosidic flavonoids (yellow colour) • 5-15% sugars (glucose & sucrose)

  12. Semi-Synthetic Derivatives of Glychyrrhizic acid • Hemisuccinate Carbenoxolone Na, semisynthetic derivative of glycyrrhetic acid for Rx gastric & duodenal ulcers (inc. Na + dec. K S/E)

  13. Panax ginsengRoots (Araliaceae) China, Korea & Russia Other related Panax spp. P. quinquefolium (American ginseng) USA & Canada P. notoginseng (Sanchi-ginseng) China Pan=all (Gr) akos =remedy (Gr) →→ “Universal remedy” جينسنغ

  14. Biological Activities of Ginseng Traditional remedy in China & Russia: • Rx of anaemia, diabetes, gastritis, insomnia, sexual impotence • General restorative, promoting health and longevity • White ginseng (peeled roots) • Red ginseng (steamed roots) reputed enhancing biological activity

  15. Pharmacology Classified as ADAPTOGEN = agent helps the body to adapt to stress (physical/ chemical/ biological stress) Unspecific enhancement of the body’s resistance to exogenous stress or noxes • Improve stamina & concentration • Provides a normalizing & restorative effect • Promoted as an aphrodisiac • Korean root is best Most expensive • Long term use lead to corticosteroid poisoning symptoms e.g. HTN or hypotension, nervousness, sleeplessness, tranquilizing effects [ginseng-abuse syndrom] • Antioxidant • Affect both CNS & neuroendocrine functions • Alter lipid & carbohydrate metabolism • Modulate immune functions??

  16. Chemistry • Triterpenoid saponins (30 ginsenosides ) • Ginsenosides (Japanese) or Panaxosides (Russians) • Panaxosides A, B,D, E,…. • Derivatives of Protopanaxadiol (aglycone) or Protopanaxatriol (aglycone) • Rb1 is the most abundant Diol series • Rg1 major representative of the Triolesters • Red ginseng is rich in partially hydrolysed esters & glycosides (inc. antioxidant phenolics) • White ginseng ginsenosides as esters

  17. Panaxadiols

  18. Panaxatriols

  19. Dosage & Standardization • PO 100-600mg/day in divided doses • Standardized product to contain minimum of 5% ginsenosides/ dose Regimen for maximum efficacy: 4 weeks on, followed by 2 weeks off

  20. Siberian or Russian GinsengEleutherococcus senticosus • Inexpensive alternative to Panax spp • Roots, family Araliaceae

  21. Eleutherococcus senticosus • Adaptogen • Eleutherosides (diff. chemical classes) • Eleutheroside E =syringaresinol diglucoside (main) lignan glycoside • Eleutheroside B = syringin (phenylpropane glycoside) • PO 100-200mg BID • Standardized 0.8% eleutherosides B & E/dose • 4 weeks on, 2 weeks off

  22. Eleutherosides

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