Xiang-Zhong Huang

Cytotoxic deoxybenzoins and diphenylethylenes from Arundina graminifolia.

Eight new C-4-alkylated deoxybenzoins (1-8), three new diphenylethylenes (9-11), and five known diphenylethylenes were isolated from Arundina graminifolia. The structures of 1-11 were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Compounds 9-11 are the first naturally occurring diphenylethylenes possessing a hydroxyethyl unit. Compounds 1-11 were evaluated for cytotoxicity against five human tumor cell lines. Compounds 4, 5, and 9-11 showed significant cytotoxicity against five cancer cell lines, with IC50 values ranging from 1.8 to 8.7 μM.

New amide alkaloids from Piper longum

Bioassay-guided phytochemical investigation on Piper longum resulted in the isolation of two new compounds. By analyses of the MS, IR, UV, 1D and 2D NMR data, the two new compounds were identified as 3β, 4α-dihydroxy-1-(3-phenylpropanoyl)-piperidine-2-one (1) and (2E, 4E, 14Z)-6-hydroxyl-N-isobutyleicosa-2,4,14-trienamide (2). In vitro anti-HBV bioassay demonstrated compound 1 possessed remarkable activity suppressing the secretion of HBeAg in Hep G2.2.15 cell line, with an IC(50) value of 0.21mM and SI value of 16.4.

Acutissimanide, a new lignan with antioxidant activity isolated from the bark of Quercus acutissima Carruth

Acutissimanide (1), a new lignin, together with 11 known polyphenols (2–12) were isolated from the bark of the deciduous oak tree, Quercus acutissima Carruth. The structure of compound 1 was determined using multidimensional 1H and 13C NMR and mass spectroscopy. The antioxidant properties of compounds 1–12 were investigated using a 1,1-diphenyl-2-picryhydrazyl radical-scavenging assay with compounds 6–11 displaying significant antioxidant activity (EC50 values of 5.2–23.7 μM). Our findings suggest the extracts of Q. acutissima Carruth are a potential source of natural antioxidant additives for use in the food and other allied industries.

Five new prenylated chalcones from Desmodium renifolium

Five unusual new prenylated chalcones, renifolins D-H (1-5), were isolated from whole Desmodium renifolium plants. All of their structures were determined by spectroscopic methods including 1D and 2D NMR. All of the isolates were evaluated for cytotoxicity using five tumor cell lines. Compounds 2 and 3 exhibited cytotoxicity against A549 cells, with IC50 values of 2.8 and 2.2 μM, respectively.

Four New Diterpene Glucosides from Perovskia atriplicifolia

Four new diterpene glucosides, namely perovskiaditerpenosides A – D (1 – 4), were isolated from the BuOH extract of Perovskia atriplicifolia. Their structures were well elucidated by chemical methods and comprehensive spectroscopic analyses including MS, IR, and NMR (1D and 2D). The newly isolated compounds were screened for their cytotoxic activity against HepG2, NB4, HeLa, K562, MCF7, PC3, and HL60. The obtained results indicated that the new compounds possessed considerable cytotoxic activity.

α-Glucosidase Inhibitory and Anti-Inflammatory Coumestans from the Roots of Dolichos trilobus

Four new coumestans dolichosins Au200a-u200aD (1: -4: ) were isolated from the roots of Dolichos trilobus, together with four known compounds: isosojagol (5: ), phaseol (6: ), psoralidin (7: ), and 4″,5″-dehydroisopsoralidin (8: ). Their structures were elucidated on the basis of spectroscopic data interpretation, mass spectrometric analyses, and the comparison with literature data of related compounds. The anti-inflammatory activity of these compounds (1: -8: ) was evaluated through the inhibition of nitric oxide production in lipopolysaccharide-activated murine macrophage RAW 264.7 cells, in which compounds 1: and 6: displayed moderate inhibitory activity and no cytotoxic effects. In a α-glucosidase inhibitory assay, compounds 1: and 5: -8: exhibited appreciable inhibition on α-glucosidase. Especially compounds 1, 7: , and 8: showed IC50 values lower than 20.0u2009µM.

Antioxidant and alpha-glucosidase inhibitory activities of isoflavonoids from the rhizomes of Ficus tikoua Bur

Abstract A new unique isoflavone derivatives with a cyclic-monoterpene-substituent, ficusin C (1), together with five known compounds (2–6), were isolated from the rhizomes of Ficus tikoua. Their structures were elucidated on the basis of spectroscopic data interpretation, mass spectrometric analysis and comparison with literature data of related compounds. Antioxidant and α-glucosidase inhibitory activities of these compounds were evaluated by 1,1-diphenyl-2-picryhydrazyl (DPPH) radical-scavenging assay and α-glucosidase inhibitory experiment, respectively.