Phochrodines A-D, first naturally occurring new chromenopyridines from mangrove entophytic fungus Phomopsis sp 33#

Four new chromenopyridine derivatives, phochrodines A-D (1 - 4), were identified from mangrove entophytic fungus Phomopsis sp. 33# by means of various modern chromatographic, spectroscopic and single crystal X-ray diffraction techniques. Compounds 1 - 4 with an unusual 5H-chromeno[4,3-b]pyridine skeleton were the first naturally occurring chromenopyridines. Their anti-inflammatory, antioxidant and cytotoxic activities were evaluated. 3 and 4 showed moderate inhibition of nitric oxide production with IC50 values of 49.0 as well as 51.0 mu M, respectively. 4 had well ability to scavenge DPPH radical with IC50 value of 34.0 mu M. The four had no cytotoxic activity for MDA-MB-435 breast cancer cells.