Tetrocarcin Q, a New Spirotetronate with a Unique Glycosyl Group from a Marine-Derived Actinomycete Micromonospora carbonacea LS276

摘要

A new spirotetronate glycoside tetrocarcin Q ( 1 ) and six known analogues tetrocarcin A ( 2 ), AC6H ( 3 ), tetrocarcin N ( 4 ), tetrocarcin H ( 5 ), arisostatin A ( 6 ), and tetrocarcin F1 ( 7 ) were isolated from the fermentation broth of the marine-derived actinomycete Micromonospora carbonacea LS276. Their chemical structures were established on the basis of 1D- and 2D-NMR spectroscopy, as well as HR-ESI-MS analysis. The absolute configurations of their stereogenic carbons were determined by circular dichroism (CD) analysis. Compound 1 possesses 2-deoxy-allose, which is a unique sugar type at the C-9 position. This type has not been found in the previously reported spirotetronate glycosides. Compound 1 displayed moderate antibacterial activity against Bacillus subitlis ATCC 63501 with minimum inhibitory concentration (MIC) value of 12.5 μM.