Title: Ginkgolides
Literature References: Family of bioactive terpenes isolated from the root bark and leaves of Ginkgo biloba L., Ginkgoaceae. Specific platelet activating factor (PAF) antagonists. Isoln from leaves: S. Furukawa, Sci. Papers Inst. Phys. Chem. Res. Jpn. 19, 27 (1932), C.A. 27, 303 (1933). Isoln from root bark and characterization: M. Maruyama et al., Tetrahedron Lett. 1967, 299; K. Nakanishi, Pure Appl. Chem. 14, 89 (1967); from leaves: N. Sakabe et al., Chem. Commun. 1967, 259; K. Okabe et al., J. Chem. Soc. C 1967, 2201. Crystal structure of B: L. Dupont et al., Acta Crystallogr. C42, 1759 (1986); of A and C: M. Sbit et al., ibid. C43, 2377 (1987). Total synthesis of (±)-B: E. J. Corey et al., J. Am. Chem. Soc. 110, 649 (1988); of (±)-A: E. J. Corey, A. K. Ghosh, Tetrahedron Lett. 29, 3205 (1988). Enantioselective route to B: E. J. Corey, A. V. Gavai, ibid., 3201. Review of syntheses: E. J. Corey, Chem. Soc. Rev. 17, 111-133 (1988). 1H- and 13C-NMR: C. Roumestand et al., Tetrahedron 45, 1975 (1989). Effect on PAF receptor binding: R. Korth et al., Eur. J. Pharmacol. 152, 101 (1988). Review: P. Braquet et al., Med. Res. Rev. 11, 295-355 (1991). Review of physical properties: T. A. van Beek, Bioorg. Med. Chem. 13, 5001-5012 (2005).
Properties: Ginkgolides are sol in acetone, ethanol, methanol, ethyl acetate, THF, dioxane, acetic acid, trifluoroacetic acid, acetonitrile, pyridine, DMSO; sparingly sol in ether, water. Insol in hexane, benzene, chloroform, carbon tetrachloride.
Derivative Type: Ginkgolide A
CAS Registry Number: 15291-75-5
Manufacturers' Codes: BN-52020
Molecular Formula: C20H24O9
Molecular Weight: 408.40
Percent Composition: C 58.82%, H 5.92%, O 35.26%
Properties: Bitter crystals from ethanol, mp ~300° (dec). [a]D24 -53.4° (c = 1 in ethanol). uv max (ethanol): 219 nm (log e 2.72).
Melting point: mp ~300° (dec)
Optical Rotation: [a]D24 -53.4° (c = 1 in ethanol)
Absorption maximum: uv max (ethanol): 219 nm (log e 2.72)
Derivative Type: Ginkgolide B
CAS Registry Number: 15291-77-7
CAS Name: (1b)-1-Hydroxyginkgolide A
Manufacturers' Codes: BN-52021
Molecular Formula: C20H24O10
Molecular Weight: 424.40
Percent Composition: C 56.60%, H 5.70%, O 37.70%
Literature References: Review of pharmacology and PAF-antagonism: P. Braquet, R. H. Bourgain, Adv. Exp. Med. Biol. 215, 215-235 (1987). Clinical trial in asthma: K.-H. Hsieh, Chest 99, 877 (1991); in severe sepsis: J. F. Dhainaut et al., Crit. Care Med. 22, 1720 (1994).
Properties: Bitter crystals from ethanol, mp ~300° (dec). [a]D24 -52.6° (c = 1 in ethanol). uv max (ethanol): 219 nm (log e 2.37). Log P (water/n-octanol): 1.72. pKa1 7.14; pKa2 8.60; pKa3 11.89.
Melting point: mp ~300° (dec)
pKa: pKa1 7.14; pKa2 8.60; pKa3 11.89
Optical Rotation: [a]D24 -52.6° (c = 1 in ethanol)
Log P: Log P (water/n-octanol): 1.72
Absorption maximum: uv max (ethanol): 219 nm (log e 2.37)
Derivative Type: Ginkgolide C
CAS Registry Number: 15291-76-6
CAS Name: (1a,7b)-1,7-Dihydroxyginkgolide A
Manufacturers' Codes: BN-52022
Molecular Formula: C20H24O11
Molecular Weight: 440.40
Percent Composition: C 54.54%, H 5.49%, O 39.96%
Properties: Bitter crystals from ethanol, mp ~300° (dec). [a]D24 -14.7° (c = 1 in ethanol). uv max (ethanol): 220 nm (log e 2.30).
Melting point: mp ~300° (dec)
Optical Rotation: [a]D24 -14.7° (c = 1 in ethanol)
Absorption maximum: uv max (ethanol): 220 nm (log e 2.30)
Use: Reference compd for PAF receptors in biological systems. |