Inhibitory effects of Egyptian folk medicines on human immunodeficiency virus (HIV) reverse transcriptase
el-Mekkawy, S.; Meselhy, M.R.; Kusumoto, I.T.; Kadota, S.; Hattori, M.; Namba, T.
Chemical and Pharmaceutical Bulletin 43(4): 641-648
1995
ISSN/ISBN: 0009-2363 PMID: 7541317 DOI: 10.1248/cpb.43.641Document Number: 298372
Extracts of 41 medicinal plants used in Egyptian folk medicine were screened for their inhibitory effects on human immunodeficiency virus-1 reverse transcriptase. The extracts of the fruits of Phyllanthus emblica, Quercus pedunculata [Q. robur] and Rumex cyprius and the fruits of Terminalia bellerica [T. bellirica], T. chebula and T. horrida, exhibited significant activities, with IC50 values of <=50 micro g/ml. Bioassay-guided fractionation of the methanol extract of P. emblica fruits yielded putranjivain A as a potent inhibitory substance (IC50 value of 3.9 micro M), and 4 other compounds which were identified as 1,6-di-O-galloyl- beta -D-glucose; 1-O-galloyl- beta -D-glucose; kaempferol-3-O- beta -D-glucoside; quercetin-3-O- beta -D-glucoside; and digallic acid. The inhibitory mode of action of putranjivain A, 1,6-di-O-galloyl- beta -D-glucose and digallic acid was non-competitive with respect to the substrate but competitive with respect to a template-primer. The stereochemistry of putranjivain A was elucidated from NMR spectroscopy.