Author/Authors :
Wang، نويسنده , , Wei-Guang and Li، نويسنده , , Xiao-Nian and Du، نويسنده , , Xue and Dong، نويسنده , , Ke and Zhao، نويسنده , , Wei and Wu، نويسنده , , Hai-Yan and Kong، نويسنده , , Ling-Mei and Li، نويسنده , , Xiao-yan and Pu، نويسنده , , Jian-Xin and Sun، نويسنده , , Han-Dong، نويسنده ,
Abstract :
Two novel caged ent-kauranoids, neolaxiflorins D (1) and E (2), along with three other new ent-kauranoids, neolaxiflorins F–H (3–5), and a known one, eriocalyxin B (6), were obtained from Isodon eriocalyx var. laxiflora. Neolaxiflorin D (1) is the first 15,16-seco-16,17-dinor-ent-kaurane diterpenoid, and neolaxiflorin E (2) is the first 15,16-seco-17-homo-ent-kauranoid. The absolute configurations of ent-kauranoids 1 and 2 were determined by single-crystal X-ray diffraction analyses. Structural analysis of intermediate compounds 3–5 indicated that eriocalyxin B (6) is a biogenetic precursor of caged ent-kauranoids 1 and 2 as illustrated. The cytotoxic activity of the new compounds was evaluated by an MTT assay.
