title: Three Sesquiterpenoid Dimers from Chloranthus japonicus: Absolute Configuration of Chlorahololide A and Related Compounds.
abstract: A novel sesquiterpenoid dimer, named multistalide C (1), together with two known congeners, shizukaols C (2) and D (3), was isolated from the whole plant of Chloranthus japonicus Sieb. The structures of compounds 1-3 were elucidated by extensive HR-ESI-MS, 1D, and 2D NMR spectroscopic analysis. Compounds 1-3 exhibited significant toxic effects on brine shrimp larvae (Artemia salina). The absolute configuration of 1 was established by CD/TDDFT calculations. The related compound chlorahololide A was also reinvestigated. The previous assignment of the absolute configuration of chlorahololide A and several related sesquiterpenoid dimers, based on an incorrect application of the exciton chirality method, is criticized.
authors.affiliation: Xi'an Botanical Garden, Institute of Botany of Shaanxi Province, Xi'an, 710061, People's Republic of China.
authors.forename: Xin-Wei
authors.initials: XW
authors.lastname: Shi
authors.affiliation: Xi'an Botanical Garden, Institute of Botany of Shaanxi Province, Xi'an, 710061, People's Republic of China.
authors.forename: Qiang-Qiang
authors.initials: QQ
authors.lastname: Lu
authors.affiliation: Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Pisa, Italy.
authors.forename: Gennaro
authors.identifier: http://orcid.org/0000-0002-0869-5076
authors.initials: G
authors.lastname: Pescitelli
authors.affiliation: Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Pisa, Italy.|Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Zagreb, Croatia.
authors.forename: Trpimir
authors.initials: T
authors.lastname: Ivšić
authors.affiliation: Xi'an Botanical Garden, Institute of Botany of Shaanxi Province, Xi'an, 710061, People's Republic of China.
authors.forename: Jun-Hui
authors.initials: JH
authors.lastname: Zhou
authors.affiliation: Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Science, Northwest A&F University, Yangling, 712100, People's Republic of China.
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Gao
mesh_terms: D002942:Circular Dichroism; D019281:Dimerization; D009682:Magnetic Resonance Spectroscopy; D019684:Magnoliopsida / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D011789:Quantum Theory; D012717:Sesquiterpenes / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D010936:Plant Extracts; D012717:Sesquiterpenes; C519126:chlorahololide A
keywords: TDDFT calculations; brine shrimp larvae toxicity; electronic circular dichroism; exciton chirality method; natural products; structure elucidation