LC-MS guided isolation and dereplication of Lycopodium alkaloids from Lycopodium cernuum var. sikkimense of different geographical origins

Yu Tang; Na Li; Yike Zou; Yanran Ai; Guang-Lei Ma; Ezzat E A Osman; Juan Xiong; Junmin Li; Ze-Xin Jin; Jin-Feng Hu

doi:10.1016/j.phytochem.2019.01.006

LC-MS guided isolation and dereplication of Lycopodium alkaloids from Lycopodium cernuum var. sikkimense of different geographical origins

Phytochemistry. 2019 Apr:160:25-30. doi: 10.1016/j.phytochem.2019.01.006. Epub 2019 Jan 22.

Authors

Yu Tang¹, Na Li², Yike Zou³, Yanran Ai⁴, Guang-Lei Ma¹, Ezzat E A Osman⁵, Juan Xiong¹, Junmin Li⁶, Ze-Xin Jin², Jin-Feng Hu⁷

Affiliations

¹ Department of Natural Products Chemistry, School of Pharmacy, Fudan University, Shanghai, 201203, PR China.
² Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, 318000, Zhejiang, PR China.
³ Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA.
⁴ Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA, 02138, USA.
⁵ Department of Natural Products Chemistry, School of Pharmacy, Fudan University, Shanghai, 201203, PR China; Laboratory of Medicinal Chemistry, Theodor Bilharz Research Institute, Kornaish El-Nile St., Giza, 12411, Egypt.
⁶ Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, 318000, Zhejiang, PR China. Electronic address: [email protected].
⁷ Department of Natural Products Chemistry, School of Pharmacy, Fudan University, Shanghai, 201203, PR China; Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, 318000, Zhejiang, PR China. Electronic address: [email protected].

PMID: 30682681
DOI: 10.1016/j.phytochem.2019.01.006

Abstract

Lycopodium alkaloids (LAs) are the characteristic metabolites of club mosses. Chemical differences often exist in different specimens of a single plant species collected from different geographic origins. In this study, a preliminary LC-MS detection and dereplication analyses of alkaloidal constituents of Lycopodium cernuum var. sikkimense (Müll. Hal.) C.B. Clarke (LCVS2) collected from Fujian province led to the isolation and characterization of three undescribed LAs, lycocernuskines A-C, and six known cernuane-type LAs. The known compounds were previously isolated from the same plant species (LCVS1) collected from Chongqing, and so their dereplication in LCVS2 was accomplished based on their retention times (t_R) and the quasi-molecular ion peaks in the LC-MS fingerprint. Chemical structures were identified by spectroscopic methods, single-crystal X-ray diffraction analysis, and electronic circular dichroism calculations. Lycocernuskines A and B are the first two examples of C-12 hydroxylated phlegmarane-type LAs bearing a nitrone residue at the quinoline ring. The isolates were evaluated for their anti-AChE and neuroprotective effects.

Keywords: Cernuine (PubChem CID: 442472); Chemical compounds studied in this article; Dereplication; Isolation; LC-MS analysis; Lycocernuine (PubChem CID: 442481); Lycocernuskines; Lycopodiaceae; Lycopodium cernuum var. sikkimense.

MeSH terms

Alkaloids / chemistry*
Alkaloids / isolation & purification*
Chromatography, Liquid
Geography*
Lycopodium / chemistry*
Models, Molecular
Molecular Conformation
Tandem Mass Spectrometry

Substances

Alkaloids