New Flavanol Dimers from the Bark of Celtis tetrandra and Their TRAIL Resistance-Overcoming Activity

Abstract

In the courses of our search for bioactive natural products on TRAIL resistance-overcoming activity, the active EtOAc extract from the bark of Celtis tetrandra was chemically investigated. The fractionation of the extract resulted in the isolation of flavanols; (+)-afzelechin (1), (-)-epiafzelechin (2), (-)-catechin (3), and two new flavanol dimers; (-)-epiafzelechin-(4α8)-(-)-catechin (4) and (-)-epiafzelechin-(4α 8)-(-)-epicatechin (5). All isolated compounds 1-5 were tested for their TRAIL resistance-overcoming activity against AGS cells at the concentrations from 5-20 µM. It is likely that the flavanol dimers 4 and 5 exhibited weak activity in the range of the concentration of 10-20 µM as compared with the standard.

A comprehensive account on ethnobotany, phytochemistry and pharmacological insights of genus Celtis

“… Anthocyanin Pelargonidin-3,5-di-O-glucoside C. australis fruits & Leaves Water and ethanol extracts UHPLC–QqQ-MS/MS, UV Croatia [ 32 ] 58. Flavanol Afzelechin C. tetrandra Barks Ethyl acetate extract MS, H-NMR, C-NMR, HRESIMS Thailand [ 116 ] 59. Flavanol Catechin C. pallida Leaves & Fruits Methanol, methanol-water or acetone extract HPLC Mexico [ 117 ] C. tetrandra Barks Ethyl acetate extract MS, H-NMR, C-NMR, HRESIMS Thailand [ 116 ] C. tournefortii Fruits Methanol extract HPLC, UV Turkey [ 113 ] C. tournefortii Leaves & Young twigs Methanol–dichloromethane extract HPLC-TOF/MS Turkey [ 114 ] 60.…”

“… Flavanol Afzelechin C. tetrandra Barks Ethyl acetate extract MS, H-NMR, C-NMR, HRESIMS Thailand [ 116 ] 59. Flavanol Catechin C. pallida Leaves & Fruits Methanol, methanol-water or acetone extract HPLC Mexico [ 117 ] C. tetrandra Barks Ethyl acetate extract MS, H-NMR, C-NMR, HRESIMS Thailand [ 116 ] C. tournefortii Fruits Methanol extract HPLC, UV Turkey [ 113 ] C. tournefortii Leaves & Young twigs Methanol–dichloromethane extract HPLC-TOF/MS Turkey [ 114 ] 60. Flavanol Epiafzelechin C. tetrandra Barks Ethyl acetate extract MS, H-NMR, C-NMR, HRESIMS Thailand [ 116 ] 61.…”

Bioassay‐guided isolation of anti‐inflammatory constituents from Celtis sinensis leaves

“…Previous studies on the plants of the genus Celtis led to the isolation of flavonoids (Kaltenhauser et al., 2010; Spitaler et al., 2009; Zehrmann et al., 2010), terpenoids (Badoni et al., 2011; Hwang et al., 2003; Kim et al., 2005), phenolic acids (Badoni et al., 2010; Hoang et al., 2012), and amide compounds (Al‐Taweel et al., 2012; Kim & Lee, 2003; Kim, Lee, et al., 2005). Recently, two new flavanol dimers were isolated from the bark of Celtis tetrandra (Seephonkai et al., 2018). Extracts from genus Celtis have demonstrated anti‐inflammatory effects.…”

The complete chloroplast genome sequence of Celtis tetrandra

“…Celtis tetrandra is an important indigenous and greening tree species in Yunnan (Feng 2018). The extract from the bark of C. tetrandra also showed TRAIL resistanceovercoming activity (Seephonkai et al 2018). However, there have been no genomic studies on C. tetrandra.…”

“…The extract from the bark of C. tetrandra also showed TRAIL resistance-overcoming activity (Seephonkai et al. 2018 ). However, there have been no genomic studies on C. tetrandra .…”