From a whole plant of a fern, Diplazium subsinuatum, three new hopane-triterpene lactone glycosides, diplaziosides V-VII (1-3), were isolated, together with a new monoacetyl derivative (4) of diplazioside VII (3). Compounds 1-3 were defined as the respective 3-O-[β-D-glucopyranosyl-(1→2)]-β-D-glucopyranosides of 3β,24-dihydroxyhopan-28,22-olide (1), of 3β,17,24-trihydroxyhopan-28,22-olide (2), and of (22R)-3β,24,30-trihydroxyhopan-28,22-olide (3), and 4 as the 6"-O-acetate of 3, respectively, on the basis of spectral evidence. 1-3 are new in their glycoside structures but also in their triterpene structures. Furthermore, in compounds 1-4, the coupling between the 24-hydroxy proton and one of the 24-methylene protons showed a very large J-value (11.4Hz); based on this 1H-NMR evidence, etc., preferred conformations of the 24-hydroxymethylene groups in 1-4 are also inferred. In a similar manner, 1H-NMR coupling patterns of the 24-hydroxymethylene in the monoglucoside (2a) and aglycone (2b), derived from 2, are also reported and discussed here.
fern, Diplazium subsinuatum, hopane-triterpene lactone glycoside, diplazioside V, diplazioside VI, diplazioside VII
NCBI PubMed ID: 11145147Publication DOI: 10.1248/cpb.48.1930Journal NLM ID: 0377775Publisher: Pharmaceutical Society Of Japan
Correspondence: nakanisi@pharm.setsunan.ac.jp
Institutions: Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Japan
Methods: 13C NMR, 1H NMR, IR, FAB-MS, TLC, acid hydrolysis, GLC, HPLC, extraction, optical rotation measurement, CC, melting point determination, precipitation, derivatization, evaporation, centrifugation, HR-FAB-MS
Found