Structure determination of kanglemeisu A by X-ray diffraction method

Kanglemeisu A (C50H63O19B.CH3OH) is the product of an actinomyces species from a soil sample gathered in China Kanglemeisu A belongs to the triclinic system, space group P1, unit cell: a = 12.760(3), b = 10.287(2), c = 9.926(2) A, alpha = 88.39(2), beta = 78.64(2), gamma = 89.14(2). RANTAN direct method is used to solve the structure. The final discrepancy factor is R = 0.0689, after atom coordinates and temperature factors have been refined with full matrix least squares. The structure skeleton consists of four parts, the naphthalene nucleus connected to the 5-membered ring, a 17-membered ring connected to C2, a dimethyl butane diacid extended out from C20, beta-D-3,4-OO' methylenedigitoxose passing through an oxygen bridge O6 and linked to C27 of ansa ring.