“…In the 1 H NMR spectrum (experimental) of compound 5 , the presence of vinylic proton at 5.12 (1H, t, J = 3.0 Hz, H-12), one oxymithine proton at 4.11 (1H, br s, H-3), five tertiary methyls at 1.10, 1.08, 1.02, 0.82, and 0.78 (all singlets), and two secondary methyls at 0.90, (3H, d, J = 6.0 Hz) and 0.77 (3H, d, J = 6.0 Hz) were observed, unambiguously confirming the presence of Δ 12 -ursane skeleton [ 51 ]. The 13 C NMR spectrum (experimental part) exhibited a total of 30 carbon signals which were sorted out into nine CH 2 , seven CH 3 , seven CH including one olefinic, and one oxygen-bearing carbon as well as seven quaternary carbons.…”