PUB - Publikationen an der Universität Bielefeld

Three new naturally-occurring 3,4-dihydroquinoline-2-one derivatives: 8-Hydroxy-3,4-dihydro-1H-quinolin-2-one (1), 3,4-dihydro-1H-quinolin-2-one (2) and 8-methoxy-3,4-dihydro-1H-quinolin-2-one (3), together with linoleic acid, glycerol monolinoleate and phenyl acetic acid were isolated from the Streptomyces sp. LGE21, derived from Lemna gibba. Structures of the new alkaloids (1-3) were determined by extensive 1D and 2D NMR, and MS measurements. In vitro cytotoxic studies of 1-3 and linoleic acid, in comparison with the original extract were assayed against liver cancer HEPG2 cell line and the human cervix carcinoma cell line (KB-3-1). The antimicrobial activity of the strain extract and compounds 1-3 were achieved as well. The new metabolites exhibited weak cytotoxic activities against cancer cell lines and growth inhibitory activity against a panel of tested bacterial strains.