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An extract from the rhizomes of Cassumunar ginger (Zingiber purpureum Roscoe). was found to have significant α-glucosidase inhibitory activity with an IC50 value of 6.3 µg/mL. Two new phenylbutenoids, cassudimin A (1) and cassumunol N (2), and seven known compounds (3–9) were isolated. Their structures and relative configurations of two new compounds were elucidated based on spectra interpretation. Compounds 1–3, 6–9 showed more potent α-glucosidase inhibitory activity than a positive control, acarbose (IC50 = 168.0 µM). Dehydrozingerone (6) exhibited the most potent α-glucosidase inhibition with an IC50 value of 8.3 μM. Compounds 7 and 9 were found in Z. purpureum rhizomes for the first time.

From an ethyl acetate-soluble fraction of the leaves of Muntingia calabura, one new trimeric δ-tocopherol derivative named as tocomuntin A (1), together with three known δ-tocopherol derivatives (2–4) were isolated. Their structures were elucidated based on the interpretation of NMR and MS spectroscopic data. In this work, δ-tocopherol (3) was found to have α-glucosidase inhibitory activity for the first time (IC50, 47.3 μM).

The phytochemical investigation of the EtOAc-soluble fraction of the aerial parts of Solanum procumbens Lour. has been carried out to obtain seven compounds, including a new 8,3′-neolignan named so...

From the EtOAc-soluble extract of the stems of Streblus ilicifolius (Moraceae), two new secondary metabolites named strebluses A (1) and B (2) were isolated. Their chemical structures have been concluded based on the chemical derivatisation and the spectroscopic interpretation. All compounds have been tested for their tyrosinase inhibitory activity. They showed weaker inhibitory activity than that of kojic acid (IC50, 44.6 µM).

Bioactivity-guided isolation of the CHCl3-soluble fraction of the stems of Salacia chinensis L. (Celastraceae) was carried out to obtain a new 7',9-epoxylignan (1) and three 7,9':7',9-diepoxylignans (2-4). The absolute configuration of 1 was elucidated based on NMR and ECD spectroscopic data interpretation. All isolated lignans showed intermediate α-glucosidase inhibitory activity with the IC50 values ranging from 28.5 to 85.6 µM.

From the methanolic extract of the rhizomes of Boesenbergia pandurata, a new flavanone derivative named (2R,7″S)-8-(1-phenyl-2-carboxyethyl)pinocembrin (1) and four known flavonoids (2–5) were isol...

Bioactivity-guided isolation of the CHCl3-soluble fraction of the roots of Calotropis gigantea was carried out to obtain a new cardenolide glycoside, caloside G. Its absolute structure was elucidated based on NMR and ECD spectroscopic data interpretation. Caloside G showed noteworthy cytotoxicity against the PANC-1 human pancreatic and HeLa human cervical carcinoma cell lines, with the submicromolar IC50 values of 0.038 and 0.09 µM, respectively.

Bioactivity-guided fractionation of the CHCl3-soluble extract of the roots of Paramignya trimera was carried out to obtain a new acridone alkaloid, paratrimerin I. Its structure was elucidated base...

Phytochemical study on the EtOAC-soluble extract of the leaves of Gnetum gnemon furnished the isolation of a new phenylheptanoid, gnetumal (1), along with five known compounds (2–6). Their isolatio...

From the methanol extract of the wood of Mangifera gedebe (Anacardiaceae), we had isolated a new secondary metabolite named gedebic acid (1) and six known compounds (2–7). Their chemical structures were determined by spectroscopic methods as well as comparing with data in the literature. All compounds were tested for α-glucosidase inhibitory activity. Compounds 4–7 showed more potent inhibitory activity, with IC50 values ranging from 45.3 to 142.6 μM, than that of a positive control acarbose (IC50, 214.5 μM).

From an EtOAc-soluble fraction of the stem barks of Swintonia floribunda (Anacardiaceae), one new dimeric alkylresorcinol named integracin E (1), together with 4 known compounds (2–5) were ...

From an CHCl3-soluble fraction of the stems of Semecarpus caudata, one new bischromanone named semecarpanone (1), together with 5 known flavonoids (2–6) were isolated. Their structures were elucidated based on interpretation of spectroscopic data. The stereo-configuration of 1 was identified based on the calculated and experimental coupling constants. Compounds 4–6 showed potent tyrosinase inhibitory activity with the IC50 values ranging from 15.0 to 76.3 μM.