Enmein-type 6,7-seco-ent-Kauranoids from Isodon sculponeatus

• Published in: Journal of natural products (Washington, D.C.) Vol. 76; no. 11; pp. 2113 - 2119
• Main Authors: Jiang, Hua-Yi, Wang, Wei-Guang, Zhou, Min, Wu, Hai-Yan, Zhan, Rui, Li, Xiao-Nian, Du, Xue, Li, Yan, Pu, Jian-Xin, Sun, Han-Dong
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society and American Society of Pharmacognosy 22.11.2013; Amer Chemical Soc
• Subjects: Antineoplastic Agents, Phytogenic - chemistry; Antineoplastic Agents, Phytogenic - isolation & purification; Antineoplastic Agents, Phytogenic - pharmacology; Chemistry, Medicinal; Crystallography, X-Ray; Diterpenes; Diterpenes, Kaurane - chemistry; Diterpenes, Kaurane - isolation & purification; Diterpenes, Kaurane - pharmacology; Drug Screening Assays, Antitumor; Humans; Inhibitory Concentration 50; Isodon - chemistry; Life Sciences & Biomedicine; Lipopolysaccharides - pharmacology; Molecular Conformation; Molecular Structure; Nitric Oxide - biosynthesis; Nuclear Magnetic Resonance, Biomolecular; Pharmacology & Pharmacy; Plant Sciences; Science & Technology; ABSOLUTE-CONFIGURATION; DITERPENOIDS; TERPENOIDS
• ISSN: 0163-3864; 1520-6025
• DOI: 10.1021/np400669t

Fourteen enmein-type 6,7-seco-ent-kaurane diterpenoids, seven new ones (sculponins M–S, 1–7) and seven known compounds (8–14), were isolated from the aerial parts of Isodon sculponeatus. Compound 1 is the first example of an ent-kauranoid, possessing a 11,12-epoxy group, and compounds 6 and 7 have a rare 3,6-epoxy group. The structures were established primarily by NMR and MS methods, and the absolute configurations of 1, 3, and 6 were determined by single-crystal X-ray diffraction. Compound 14 showed significant cytotoxic activity against five human tumor lines, with IC50 values ranging from 1.0 to 3.5 μM, and it also inhibited NO production in LPS-stimulated RAW264.7 cells, with an IC50 value of 2.2 μM.