title: Podoimbricatin A, a cytotoxic diterpenoid with an unprecedented 6/6/5/6-fused tetracyclic ring system from the twigs and leaves of Podocarpus imbricatus.
abstract: Podoimbricatin A (1), a diterpenoid possessing an unprecedented 6/6/5/6-fused tetracyclic ring system, and podoimbricatin B (2), a new abietane-type diterpenoid, together with four previously reported diterpenoids and a cyclic peptide were isolated from the twigs and leaves of Podocarpus imbricatus. Their structures were established on the basis of extensive spectroscopic analyses and the relative configuration of 1 was confirmed by single-crystal X-ray diffraction analysis. A plausible biogenetic pathway involving hetero-Diels-Alder cycloaddition as a key reaction is proposed for 1. Compounds 1, 5, and 7 showed inhibitory effects against the A549 and NCI-H292 cancer cell lines.
authors: Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan 250012, PR China.
authors: Yang
authors: Y
authors: Han
authors: Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan 250012, PR China.
authors: Xia-Xia
authors: XX
authors: Di
authors: Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan 250012, PR China.
authors: Hai-Zhen
authors: HZ
authors: Li
authors: Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan 250012, PR China.
authors: Tao
authors: T
authors: Shen
authors: Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan 250012, PR China.
authors: Dong-Mei
authors: DM
authors: Ren
authors: Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan 250012, PR China.
authors: Hong-Xiang
authors: HX
authors: Lou
authors: Department of Natural Product Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan 250012, PR China. Electronic address: wangxn@sdu.edu.cn.
authors: Xiao-Ning
authors: XN
authors: Wang
mesh_terms: D045784:Abietanes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D008958:Models, Molecular; D008968:Molecular Conformation; D018515:Plant Leaves / Q000737:chemistry*; D018547:Plant Stems / Q000737:chemistry*; D013329:Structure-Activity Relationship; D064028:Tracheophyta / Q000737:chemistry*
chemical_list: D045784:Abietanes; D000972:Antineoplastic Agents, Phytogenic
keywords: Cytotoxicity; Diterpenoid; Podocarpus imbricatus; Podoimbricatin A; Podoimbricatin B