Chem. Pharm. Bull. 55(4) 516—519 (2007)

commonly known as Tulsi and is a herbaceous plant (60 cm high). It grows in India, Pakistan, Sri Lanka, and Burma, generally cultivated from Punjab. The essential oil from the aerial parts, leaves, seeds, flowers, and roots of Ocimum spp. is used as medicines. The essential oil has shown in vitro antibacterial activity against Staphylococcus aureus, Salmonella enteritidis, and Escherichia coli, antiseptic activity against Proteus vulgaris, Bacillus substilis, and Salmonella paratyph, and antifungal activity against Candida albicans, Penicillium notatum, and Microsporeum gyseum. Oils from Ocimum spp. showed insect-repellant properties and larvicidal activity against house flies, bluebottle flies, and mosquitoes. The present studies undertaken on O. basilicum in view of the reported medicinal significance have resulted in the isolation and structure elucidation of three new compounds, basilol (1), ocimol (2), and basilimoside (3), and two known constituents oleanolic acid and betulinic acid. Their structures have been elucidated as p-formylphenyl 3b-hydroxyolean-12-en-28-oate (1), 2-methoxy-4-carbomethoxyphenyl 3b-hydroxy-lup-20(29)-en-28-oate (2), and (22E)-24x -ethyl-25-methylcholesta-5,22-diene-3b -ol-3-O-Dglucopyranoside (3). Compound 3 is a rare example of steroids having a t-butyl group in the side chain. The molecular formula of basilol (1) was established as C37H52O4 by a positive FAB-MS ion at m/z 561 [M H] . The IR spectrum showed characteristic absorption bands caused by hydroxyl group (3428 cm ), aldehyde group (2815, 2730, 1685 cm ), ester carbonyl (1730 cm ), and benzene ring (1597, 1446 cm ). The UV spectrum showed absorption maxima at 283.8 nm (log e 7.6) and 218.2 nm (log e 7.5). In the H-NMR spectrum (Table 1) seven Cmethyls were indicated: five as three-proton singlets at d 0.82, 0.84, 0.90, 0.96, and 1.05 and two as a six-proton singlet at d 0.75. These along with a double doublet at d 2.81 (1H, dd, J 13.8, 4.3 Hz, H-18), a one-proton triplet at d 5.22 (1H, t, J 3.4 Hz, H-12), and the C-NMR shifts of the skeleton suggested that 1 is an oleanolic acid ester. Furthermore, a one-proton double doublet was present at d 3.20 (1H, dd, J 10.8, 4.6 Hz, H-3) connected with a carbon at d 79.2 (C-3) in the HMQC spectrum. EI-MS showed a peak of highest a.m.u. at m/z 455 due to loss of 105 a.m.u. which in the light of NMR data indicated that 1 is p-formylphenyl ester of oleanolic acid. The H-NMR spectrum showed a pformylphenyl ester moiety by signals at d 6.92 (2H, d, J 8.6 Hz, H-2 /6 ) and 7.78 (2H, d, J 8.6 Hz, H-3 /5 ) and a one-proton singlet at d 9.81 (CHO) and the corresponding carbon signals at d 115.9, 132.3, and 190.8. Furthermore, H2 /6 showed long-range connectivity in the HMBC spectrum (Fig. 1) with a quaternary carbon at d 161.4 (C-1 ), and CH 516 Vol. 55, No. 4