| Abstract: | Bioassay-guided fractionation of the whole plant of Ardisia kusukuensis led to the isolation of six new resorcinols: kusukuenols A1 (1), A 2 (2), kusukuenols B1 (3), B2 (4), and kusuennols C1 (5), C2 (6), together with 21 known compounds including six alkenyl resorcinols: 5-(8′Z-heptadecenyl) resorcinol (7), 5-(8′Z-pentadecenyl)resorcinol (8), 2-methyl-5-(8'Z- heptadecenyl)resorcinol (9), 2-methyl-5-(8′Z-pentadecenyl)resorcinol (10), oncostemonol D (11), dehydrobisgravillol (12); three alkyl resorcinols: bisgravillol (13), 1-(3,5-dihydroxyphenyl)nonan-1-one (14) and 1-(3,5-dihydroxyphenyl)heptan-1-one (15); two benzoquinones: ardisianone (16) and cornudentanone (17); two benzenoids: 4-hydroxybenzoic acid (18) and hydroquinone (19); two chlorophylls: pheophytin-a (20) and 13 2-hydroxy-(132-S)-pheophytin-a (21); six steroids: α-spinasterol (22), a mixture of β-sitosterol (23) and stigmasterol (24), a mixture of 6β-hydroxystigmasta-4-en-3-one (25), 6β-hydroxystigmasta-4,22-dien-3-one (26), and 6β-hydroxycampest-4-en- 3-one (27). The structures of these compounds were determined by spectroscopic analysis and chemical derivation. Among the isolates, compounds 2, 7, 8, 10, 15, and 19 exhibited potent antitubercular activities (MIC values ? 29.0 μg/mL) against Mycobacterium tuberculosis H37Rv in vitro. Two alkyl benzoquinones, 16 and 17 were the cytotoxic constituents. |
