| Abstract
| - From the ethyl acetate extract of the strain Streptomyces sp. isolate GW23/1540, besides 16 knownproducts, several 1H-quinazolin-4-one derivatives were isolated. (S*R*)-2-(1-Hydroxyethyl)-2-methyl-2,3-dihydro-1H-quinazolin-4-one (4) and (R*R*)-2-(1-hydroxyethyl)-2-methyl-2,3-dihydro-1H-quinazolin-4-one (5) are new natural products. 2-Methyl-3H-quinazolin-4-one (2) and 1H-quinazoline-2,4-dione (3) areknown from other bacteria and plants, respectively. From another Streptomyces sp., GW2/577, 5-methyl-1H-quinazoline-2,4-dione (6) was isolated and the structure proven by comparison with the isomeric 7.The new natural products showed no activity against the microalgae Chlorella vulgaris, Chlorellasorokiniana, and Scenedesmus subspicatus, the fungus Mucor miehei, the yeast Candida albicans, andthe bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Streptomyces viridochromogenes.
|
