title: (+)-Meyeniins A-C, Novel Hexahydroimidazo[1,5-c]thiazole Derivatives from the Tubers of Lepidium meyenii: Complete Structural Elucidation by Biomimetic Synthesis and Racemic Crystallization.
abstract: (+)-Meyeniins A-C (1-3), a novel class of sulfur-containing hexahydroimidazo[1,5-c]thiazole derivatives, were isolated from the tubers of Lepidium meyenii (maca) cultivated in Lijiang, Yunnan province, China. Guided by their biosynthetic hypothesis, a stereocontrolled biomimetic synthesis of meyeniins A-C and their individual enantiomers was efficiently accomplished by a combination of a condensation reaction and Edman degradation. The formation of high-quality crystals for X-ray crystallography occurred much more readily from a racemic mixture of (±)-meyeniin A than with the single enantiomer alone in this case. These extensive strategies, combined with circular dichroism (CD) spectra, allowed the complete structural assignments of (+)-meyeniins A-C. Among them, (+)-meyeniin A showed moderate selective cytotoxicities against the HL-60, A549 and MCF-7 human cell lines with IC50values of 14.41, 32.22, and 33.14 μM, respectively. To some extent, these findings support traditional applications of maca as healthy nutritional supplements or functional foods for cancer prevention.
authors.affiliation: Key Laboratory of Chemistry in Ethnic Medicinal Resources, State Ethnic Affairs Commission and Ministry of Education, Yunnan Minzu University , Kunming 650031, Yunnan, People's Republic of China.|Key Laboratory of Tobacco Chemistry of Yunnan Province, China Tobacco Yunnan Industrial Company, Ltd. , Kunming 650231, Yunnan, People's Republic of China.
authors.forename: Min
authors.identifier: http://orcid.org/0000-0003-1896-9832
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Chemistry in Ethnic Medicinal Resources, State Ethnic Affairs Commission and Ministry of Education, Yunnan Minzu University , Kunming 650031, Yunnan, People's Republic of China.
authors.forename: Hang-Ying
authors.initials: HY
authors.lastname: Ma
authors.affiliation: Key Laboratory of Tobacco Chemistry of Yunnan Province, China Tobacco Yunnan Industrial Company, Ltd. , Kunming 650231, Yunnan, People's Republic of China.
authors.forename: Zhi-Hua
authors.initials: ZH
authors.lastname: Liu
authors.affiliation: Key Laboratory of Tobacco Chemistry of Yunnan Province, China Tobacco Yunnan Industrial Company, Ltd. , Kunming 650231, Yunnan, People's Republic of China.
authors.forename: Guang-Yu
authors.initials: GY
authors.lastname: Yang
authors.affiliation: Key Laboratory of Chemistry in Ethnic Medicinal Resources, State Ethnic Affairs Commission and Ministry of Education, Yunnan Minzu University , Kunming 650031, Yunnan, People's Republic of China.
authors.forename: Gang
authors.initials: G
authors.lastname: Du
authors.affiliation: Key Laboratory of Chemistry in Ethnic Medicinal Resources, State Ethnic Affairs Commission and Ministry of Education, Yunnan Minzu University , Kunming 650031, Yunnan, People's Republic of China.
authors.forename: Yan-Qing
authors.initials: YQ
authors.lastname: Ye
authors.affiliation: Key Laboratory of Chemistry in Ethnic Medicinal Resources, State Ethnic Affairs Commission and Ministry of Education, Yunnan Minzu University , Kunming 650031, Yunnan, People's Republic of China.
authors.forename: Gan-Peng
authors.initials: GP
authors.lastname: Li
authors.affiliation: Key Laboratory of Chemistry in Ethnic Medicinal Resources, State Ethnic Affairs Commission and Ministry of Education, Yunnan Minzu University , Kunming 650031, Yunnan, People's Republic of China.
authors.forename: Qiu-Fen
authors.initials: QF
authors.lastname: Hu
mesh_terms: D032701:Biomimetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003460:Crystallization; D018360:Crystallography, X-Ray; D006801:Humans; D007093:Imidazoles / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D029686:Lepidium / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D035281:Plant Tubers / Q000737:chemistry*; D013844:Thiazoles / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D007093:Imidazoles; D010936:Plant Extracts; D013844:Thiazoles; C117197:imidazolone
keywords: (+)-meyeniins A−C; Lepidium meyenii (maca); biomimetic synthesis; cytotoxicity; racemic crystallization; sulfur-containing hexahydroimidazo[1,5-c]thiazole