UFLC-PDA-MS/MS Profiling of Seven Uncaria Species Integrated with Melatonin/5-Hydroxytryptamine Receptors Agonistic Assay

Abstract

Uncariae Ramulus Cum Uncis (Gou-Teng), the dried hook-bearing stems of several Uncaria plants (Rubiaceae), is a wellknown herbal medicine in China. The clinical application of Gou-Teng is bewildered for the morphological and chemical similarity between different species. In order to discern their chemical and biological difference, an ultra-fast liquid chromatography equipped with ion trap time-of-flight mass spectrometry (UFLC-IT/TOF-MS) combining with melatonin (MT 1 and MT 2 ) and 5-hydroxytryptamine (5-HT 1A and 5-HT 2C ) receptors agonistic assay in vitro was conducted on seven Uncaria species. As a result, 57 compounds including 35 indole alkaloids, ten flavonoids, five triterpenoids, five chlorogenic analogues, and two other compounds were characterized based on their MS/MS patterns and UV absorptions. Specifically, cadambine-type and corynanthein-type alkaloids were exclusively present in U. rhynchophylla and U. scandens, whereas corynoxine-type alkaloids were commonly detected in all the seven Uncaria plants. Three Uncaria species, U. rhynchophylla, U. macrophylla, and U. yunnanensis showed obviously agnostic activity on four neurotransmitter receptors (MT 1 , MT 2 , 5-HT 1A , and 5-HT 2C ). This first-time UFLCMS-IT-TOF analyses integrated with biological assay on seven Uncaria plants will provide scientific viewpoints for the clinical application of Gou-Teng.We dedicate this paper to Prof. Sun Han-Dong on the occasion of his 80th birthday. Electronic supplementary materialThe online version of this article (https ://doi. Graphic AbstractKeywords Uncariae Ramulus Cum Uncis · Uncaria plants · LCMS-IT-TOF analyses · Melatonin and 5-hydroxytryptamine receptors

The Potentials of Uncariae Ramulus Cum Uncis for the Treatment of Migraine: Targeting CGRP in the Trigeminovascular System

“…They further identified that two UR flavanols, catechin and epicatechin had agonistic activity on melatonin receptors. In addition, Zhang et al reported that the extracts of different UR species also displayed agonistic effects on melatonin receptors [ 99 ]. Several new alkaloids isolated from UR show agonistic activities on both MT1 and MT2 melatonin receptors [ 100 , 101 ].…”