A Pd-catalyzed/Cu-mediated oxidative dehydrosulfurative carbon–oxygen cross-coupling reaction of 3,4-dihydropyrimidin-1H-2-thiones (DHPMs) with aryl alcohols is described. Due to the ready availability of diverse DHPMs and aryl alcohols, the reaction method offers facile access to biologically and pharmacologically valuable 2-aryloxypyrimidine derivatives with rapid diversification.

There is no research on the chemical constituents investigation and bioactivity evaluation of Buchanania lucida Blume (Anacardiaceae). From the stems of Buchanania lucida collected at Dong Nai province, the ethyl acetate and n-butanol extracts were prepared. Four phenolic compounds: protocatechuic methyl ester (1), aloe-emodin (2), naringenin (3), and glucosyringic acid (4) were isolated from these extracts. The chemical structure of these compounds were elucidated by 1D and 2D NMR spectra and comparison with published data. These compounds were first reported in Buchanania lucida.

Our preliminary screening study revealed that the methanolic extract of Stholobus parviflorus (Roxb.) exhibited potent a-glucosidase inhibitory activity with an IC50 value of 0.05 μg mL-1. Therefore, we carried out activity-guided fractionation of the MeOH extract and isolated three compounds. These compounds were determinated as ferulic acid (1), protocatechuic acid (2) and epicatechin (3) by analysis of spectroscopic data. The IC50 values of these compounds were 45.30, 23.04 and > 100 μM, respectively. Acid tannic was used as a positive control with an IC50 value of 0.91 nM.

From the chloroform and ethyl acetate extracts of the leaves of Kalanchoe pinnata L. (Crassulaceae), two flavonoids and three phenolic compounds were isolated; named quercetin (1), 5,7,4’-trihydroxy-8,3’-dimethoxyflavone (2), gallic acid (3), ferulic acid (4) and isoferulic acid (5). Based on the NMR spectroscopy, their chemical structures were elucidated and the result was confirmed by comparison with published data.