School of Chinese Materia Medica and Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, 312 Anshanxi Road, Nankai District, Tianjin 300193, People's Republic of China.
Department of Natural Products Chemistry, School of Traditional Chinese Materia Medica, Key Laboratory of Structure-Based Drug Design &Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China.
Sci Rep. 2017 Mar 8;7:43576. doi: 10.1038/srep43576.
Germacrane-type sesquiterpenes, with a flexible 10-membered ring unit as the structural and conformational features, play a central role in the biosynthesis and synthesis of other sesquiterpenes. In this report, two pairs of new sesquiterpene alkaloids, (+)/(-)-phaeocaulin A [(+)-1/(-)-1] and B [(+)-2/(-)-2], and two pairs of new sesquiterpenes, (+)/(-)-phaeocaulin C [(+)-3/(-)-3] and D [(+)-4/(-)-4], along with one related known analog (5), were isolated from the rhizomes of Curcuma phaeocaulis. The absolute configurations of (+)-1/(-)-1, (+)-2/(-)-2, (+)-3/(-)-3 and (+)-4/(-)-4 were unambiguously determined by analysis of single-crystal X-ray diffractions and quantum chemical electronic circular dichroism (ECD) method. It is noteworthy that (+)/(-)-phaeocaulin A [(+)-1/(-)-1] and B [(+)-2/(-)-2] are two pairs of rare N-containing germacrane-type sesquiterpenes. A possible biogenetic pathway for 1-5 was postulated. All of the isolated compounds were tested for their inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages.
倍半萜类化合物，以灵活的 10 元环单元为结构和构象特征，在其他倍半萜类化合物的生物合成和合成中起着核心作用。在本报告中，从姜黄属植物根茎中分离得到了两对新的倍半萜生物碱（+）/（-）-白屈菜碱 A [(+)-1/(-)-1]和 B [(+)-2/(-)-2]，以及两对新的倍半萜（+）/（-）-白屈菜碱 C [(+)-3/(-)-3]和 D [(+)-4/(-)-4]，以及一个相关的已知类似物（5）。（+）-1/(-)-1、（+）-2/(-)-2、（+）-3/(-)-3 和（+）-4/(-)-4 的绝对构型通过单晶 X 射线衍射和量子化学电子圆二色性（ECD）方法的分析得以明确确定。值得注意的是，（+）/（-）-白屈菜碱 A [(+)-1/(-)-1]和 B [(+)-2/(-)-2]是两对罕见的含氮倍半萜类化合物。提出了 1-5 的可能生物合成途径。所有分离得到的化合物均进行了 LPS 诱导的 RAW 264.7 巨噬细胞中一氧化氮产生抑制活性测试。
