A pair of new isocoumarin enantiomers of Ludwigia hyssopifolia

Abstract

A pair of new isocoumarin derivative enantiomers, (S)-(-)-3-(3,3-dichloro-2-hydroxy-propyl)-4-chlorine-6,8-dihydroxy-isochromen-1- one (1a) and (R)-(+)-3-(3,3-dichloro-2-hydroxy-propyl)-4-chlorine-6,8-dihydroxy-isochromen-1- one (1 b), as well as seven known compounds (2–8) were isolated from Ludwigia hyssopifolia. Compounds 1a and 1 b were confirmed to be a pair of enantiomers by chiral HPLC-CD analysis, and the structure of compound 1 was determined by spectroscopic analyses including extensive 1 D (¹H NMR, ¹³C NMR) and 2 D NMR spectra (COSY, HSQC and HMBC) and MS data. And the absolute configurations of compounds 1a and 1 b were determined by the quantum chemical ECD calculations. Compounds 2–8 are firstly reported from this plant. In the in vitro assays, compounds 5 and 8 can inhibit human laryngeal cancer Hep-2 cell line growth in a dose- and time-dependent manner. In addition, compounds 2 and 4 have effects on increasing glucose uptake in vitro. Compound 2 showed a strong glucose uptake in L6 cells, with enhancements by 1.8 folds.

Graphical Abstract

Keywords:

• Ludwigia hyssopifolia
• isocoumarin derivative
• cytotoxic activity
• glucose uptake

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the grants of the National Natural Science Foundation of China (Grant No. 81860750), the Innovation Project of Graduate Education of Guangxi University of Chinese Medicine (No. YCSZ20190014), and Guangxi First-class discipline (No. 2019XK114).