Stereochemistry of Two Hydroxybiflavanonols from Garcinia cola Nuts

Abstract

The absolute configuration of two hydroxybiflavanonols from Garcinia cola nuts have been determined by CD and 500 MHz 1H NMR spectroscopy. Additionally the occurrence of atrop-isomers at room temperature as the consequence of rotational hindrance in the molecules could be demonstrated.

Effect of Garcinia hydroxybiflavanonols on protein synthesis in primary cultured rat hepatocytes

“…Isolation of the liver active constituents of G. kola seeds Garcinia biflavanonols, GB1 and GB2, were isolated from the seeds of G. kola as previously described (Sonnenbichler et al 1987). …”

“…Pharmacological studies on the biflavonoids from this seed plant showed that they have antihepatotoxic (Madubunyi 1983;Iwu 1985;Sonnenbichler et al 1987), anti-diabetic activity (Iwu et al 1990), antispasmodic effect on smooth muscle (Braide 1989), antithrombic effect (Olajide 1999), bronchodilatation in man (Orie and Ekon 1993), anti-inflammatory, and anti-viral properties (Adedeji et al 2006a). It is also active in the treatment of knee osteoarthritis (Adegbehingbe et al 2008).…”

“…Previous phytochemical investigations of G. kola resulted in the isolation of cycloartenol, 24-methylene-cycloartenol (Aplin et al 1967), andkolanone (Hussain et al 1982) from the light petroleum extract and C-3/8″-linked hydroxybiflavanonols from the ethyl acetate extract of the seeds (Sonnenbichler et al 1987).…”

“…The hydroxybiflavanonols, GBI and GB2, occurring in the seeds of G. kola (Cotterhill et al 1978;Madubunyi 1987;Sonnenbichler et al 1987) protect the liver of experimental animals against several hepatotoxic substances, such as α-amanitin, phalloidin, galactosamine, carbon tetrachloride, thioacetamide, and ethanol (Madubunyi 1983;Iwu 1986). GB1 has been found to display a clear protective activity on the liver parenchymal cells in a number of experimental models (Madubunyi 1983;Iwu 1986;Akintonwa and Esien 1990;Braide 1991;Adegoke et al 1998;Farombi 2000a).…”

“…GB1 has been found to display a clear protective activity on the liver parenchymal cells in a number of experimental models (Madubunyi 1983;Iwu 1986;Akintonwa and Esien 1990;Braide 1991;Adegoke et al 1998;Farombi 2000a). GB1 and GB2 occur as atropisomers in nature (Sonnenbichler et al 1987).…”