Saccharpiscinols A-C: Flavans with Potential Anti-Inflammatory Activities from One Actinobacteria Saccharomonospora piscinae.

Phytochemical investigation and chromatographic separation of extracts from the actinobacteria strain Saccharomonospora piscinae that was isolated from dried fishpond sediment of Kouhu township, in the south of Taiwan, led to the isolation of three new compounds, saccharpiscinols A-C (1-3, respectively), and three new natural products, namely (2S)-5,7,3',4'-tetrahydroxy-6,8-dimethylflavanone (4), methyl-4-hydroxy-2-methoxy-6-methylbenzoate (5), and (±)-7-acetyl-4,8-dihydroxy-6-methyl-1-tetralone (6). Compounds 4-6 were reported before as synthesized products, herein, they are reported from nature for the first time. The structures of the new compounds were unambiguously elucidated on the basis of extensive spectroscopic data analysis (1D- and 2D-NMR, MS, and UV) and comparison with literature data. The effect of some isolates on the inhibition of NO production in lipopolysaccharide-activated RAW 264.7 murine macrophages was evaluated. Saccharpiscinol A showed inhibitory activities against LPS-induced NO production.

Tyrosinase Inhibitors Derived from Chemical Constituents of Dianella ensifolia.

Dianella ensifolia is a perennial herb with thickened rhizome and is widely distributed in tropical and subtropical regions of Asia, Australia, and the Pacific islands. This plant has the potential to be used as a source of herbal medicine. This study investigated further phytochemistry and tyrosinase inhibitory effect of some constituents isolated from D. ensifolia. Four new flavans, (2S)-4'-hydroxy-6,7-dimethoxyflavan (1), (2S)-3',4'-dihydroxy-7-methoxy-8-methylflavan (2), (2S)-2'-hydroxy-7-methoxyflavan (3), and (2S,1'S)-4-hydroxy-4-(7-methoxy-8-methylchroman-2-yl)-cyclohex-2-enone (4), together with 67 known compounds, including 10 flavans (5−14), 5 flavanones (15−19), 3 flavone (20−22), 5 chalcones (23−27), 3 chromones (28−30), 15 aromatics (31−45), 7 phenylpropanoids (46−52), one lignan (53), 7 steroids (54−60), one monoterpene (61), one diterpene (62), 4 triterpenes (63−66), a carotenoid (67), 2 alkaloids (68 and 69), and 2 fatty acids (70 and 71) were isolated from D. ensifolia. Their structures were elucidated on the basis of physical and spectroscopic data analyses. Moreover, compounds 1−4, 8, 10−15, 20, 21, and 41 were evaluated for their mushroom tyrosinase inhibitory effect. Compounds 11 and 14 strongly inhibited mushroom tyrosinase activity with IC50 values of 8.6 and 14.5 µM, respectively.