During further bioactivity-guided fractionation, a new pregnane glycoside, hypoglaucin G (1), and a known compound, pregna-5,16-dien-3β-ol-20-one 3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→4)]β-D-glucopyranoside (2), were isolated from the EtOH extract of Dioscorea collettii vat. hypoglauca rhizomes, which induced morphological deformation of Pyricularia oryzae mycelia with minimum morphological deformation concentration values of 135 μM and 236 μM, respectively. The structure of 1 was established as 16β-(4'-methyl-5'-O-β-D-glucopyranosyl-pentanoxyl)-pregn-5-en-3β-ol-20-one 3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→4)]-β-D-giucopyranoside on the basis of chemical evidence and spectral analysis, especially by 2D NMR techniques.
pregnane glycoside, Dioscorea collettii var. hypoglauca, hypoglaucin G
NCBI PubMed ID: 10075765Publication DOI: 10.1021/np980101zJournal NLM ID: 7906882Publisher: American Society of Pharmacognosy
Correspondence: Jing YK
Institutions: Department of Natural Products Chemistry, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang 110015, China, Institute of Drug Research and Development, Northeast Pharmaceutical Corp., 37 Zhonggong Beijie, Shenyang 110026, China, Institute of Molecular & Cellular Biosciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo 113, Japan, Department of Medicine, Mount Sinai School of Medicine, Box 1178, One Gustave L. Levy Place, New York, New York 10029, USA
Methods: 13C NMR, 1H NMR, IR, TLC, GC, HPLC, optical rotation measurement, cytotoxicity assay, HMBC, HMQC, DEPT, COSY, antifungal activity test, HRMS, sulfuric acid hydrolysis, trimethylsilylation
Found