Humantenmine

J Ethnopharmacol. 2015 May 26;166:66-73.

Inhibitory effects of cytochrome P450 enzymes CYP1A2, CYP2A6, CYP2E1 and CYP3A4 by extracts and alkaloids of Gelsemium elegans roots.[Pubmed: 25764964]

METHODS AND RESULTS:
Four extracts (petroleum ether, dichloromethane, EtOAc and aqueous) of GE and two commercially available alkaloids (koumine and Humantenmine) were screened for their CYP isoforms inhibitory activity. In the case of alkaloids, koumine exhibited significant inhibitory effects on CYP2E1 while Humantenmine showed more potent inhibition on CYP2E1 and CYP2A6 (IC50 of 47.44, 18.34 and 45.87µg/ml, Ki of 31.20, 35.06 and 52.06µg/ml, respectively). Because of their relatively high Ki values, the active constituents in GE dichloromethane extract were analyzed. The UPLC-DAD-ESI-MS/MS data showed that GE dichloromethane extract contains 6 kinds of indole alkaloids (koumine, Humantenmine, humantenine, humantenirine, N-methoxytaberpsychine, and sempervirine). As for CYP1A2 and CYP3A4, the negligible inhibitions were observed.
CONCLUSIONS:
G. elegans extracts inhibited several CYP450 enzyme activities with varying potency. Strong inhibition was observed in CYP2E1 and CYP2A6 isoforms by GE dichloromethane extract, koumine and Humantenmine, inferring the involvement of alkaloids chemical constituents from GE dichloromethane extract in the effect.

J Sep Sci. 2014 Feb;37(3):308-13.

Ultrasound/microwave-assisted extraction and comparative analysis of bioactive/toxic indole alkaloids in different medicinal parts of Gelsemium elegans Benth by ultra-high performance liquid chromatography with MS/MS.[Pubmed: 24375943]

Indole alkaloids are the main bioactive/toxic components in Gelsemium elegans Benth.
METHODS AND RESULTS:
To determine the distribution and contents of indole alkaloids in its different medicinal parts, a novel and rapid method using ultra-high performance LC (UPLC) with MS/MS has been established and validated with an optimized ultrasound/microwave-assisted extraction method. Four constituents, namely, humantenidine, Humantenmine, gelsemine, and koumine, were simultaneously determined in 6 min. Chromatographic separation was achieved on an ultra-high performance LC BEH C18 column with a gradient mobile phase consisting of methanol and water (containing 0.1% formic acid both in methanol and water) at a flow rate of 0.3 mL/min. The detection was performed on a triple quadrupole electrospray MS/MS by positive ion multiple-reaction monitoring mode. All the analytes showed good linearity (r ≥ 0.9934) within a concentration range from 0.1-25 μg/mL with a LOQ of 25-50 ng/mL. The overall intra- and intervariations of four components were <4.7% with an accuracy of 97.3-101.3%.
CONCLUSIONS:
The analysis results showed that there were remarkable differences in the distribution and contents of four chemical markers in the roots, stems, and leaves of G. elegans Benth. The findings can provide necessary and meaningful information for the rational utilization of its resources.