Crystal Structure of 3S-hydroxy-7 Melleine

A new compound, 3S-hydroxy-7 melleine was isolated from the endophytic fungus Xylariasp No.2508 from the mangrove tree on the South China Sea coast. It was the first time that this kind of compound was isolated from marine fungus. The structure was elucidated by NMR data, infrared spectrum (IR) and mass spectrometry (MS). In addition, its structure was determined by the single-crystal X-ray diffraction analysis. It crystallized in monoclinic, space group P21 with a=10.8884(19) (A), b=7.2284(13) (A), c=13.398(2) (A), β=104.217(3)°,C10H10O4·H2O, Mr=212.20, V=1022.2(3) (A)3, Z=4, Dc=1.379 mg/m3, F(000)=448, μ=0.112 mm-1, the final R=0.0498, wR=0.101 for 2407 observed reflections (I＞2σ(I)). The molecular backbone of the compound includes a benzopyran ring. By comparing with the melting point and the optical rotation of the known 3R-hydroxy-7 melleine in literature, the absolute configuration of the compound was determined as 3S. It didn't exhibit antibacterial activity against Gram-positive bacterium Staphylococcus aureus at 200μg/disk in the preliminary test.