1. 15-dien-19-oic acid) was revealed as C 21 H 32 O 3 by HR-ESIMS negative-ion peak at m/z 331.1088 [M-H] -(calcd for C 21 H 31 O 3 -, 331.2278). The 1 H NMR spectrum of 5 displayed four characteristic signals, which indicated the presence of three methyls (? H 0.85, 0.96, 1.28) and one methoxyl (? H 3.38) (Table 3). The 13 C NMR spectrum of 5 exhibited 21 carbon resonances, including six quaternary carbon;The molecular formula of compound 5
2. MeOH); UV (MeOH) ? max (log ?) 202 (1.16) nm;12?-Hydroxysandaracopimaric Acid-18-O-?-D -Glucoside;IR v max,1077