Publications by authors named "Zhong-Quan Zhang"

Phytochemical investigation on the whole plant of Chloranthus japonicus (Chloranthaceae) led to the isolation and identification of three new lindenane-type sesquiterpenoid dimers, chlorajaponilides F-H (1-3), along with seven known ones (4-10). Their chemical structures were established by extensive spectral evidence. Compounds 1 and 2 are both dimeric sesquiterpenoids featuring a rare hydroperoxy group at C-5.

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Phytochemical investigation of the whole plants of Tacca plantaginea led to the isolation of 3 new withanolides and one new withanolide glucoside, named plantagiolides K-N (1-4), together with one known withanolide, 4 known withanolide glucosides, and 2 known taccalonolides. Their structures were elucidated by extensive spectroscopic analysis. Compound 4 is the first withanolide glycoside which the sugar moiety is attached at C-7.

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A new spirostanol sapogenin and two spirostanol saponins, tentatively named reineckiagenin A (1), reineckiagenoside A (2), and reineckiagenoside B (3), were isolated from the whole plant of Reineckia carnea. By detailed analysis of their 1D and 2D NMR spectra, chemical methods, and by comparison with spectra data of known compounds, the structures of the new steroids were determined to be 25(S)-5β-spirostan-1β,3β,17α-triol (1), 25(S)-5β-spirostan-1β,3β,17α-triol 1-O-β-D-xylopyranoside (2), 25(S)-5β-spirostan-1β,3β,17α-triol 1-O-α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranoside (3). Compounds 1, 2, and 3 are the first naturally occurring steroids with unique structural feature of 5β-spirostan-1β,3β,17α-trihydroxyl.

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HL-37, a novel anthracene derivative, exhibited potent anticancer activity in many kinds of cancer cells. However, the exact mechanism and signaling pathway involved in HL-37-induced apoptosis have not been fully elucidated. Therefore, we explored the mechanisms of HL-37-mediated apoptosis in MCF-7 and MDA-MB-435 human breast cancer cells.

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Many anthracene derivatives possess excellent anti-tumour activity and are extensively used clinically as anti-tumour agents. However, their clinical use is frequently limited by emergence of multidrug resistance (MDR) in tumour cells. Therefore, new agents with the ability to overcome MDR are needed for cancer treatment.

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Two new cucurbitacins, endecaphyllacins A (1) and B (2), together with six known analogues (3-8), were isolated from the tubers of Hemsleya endecaphylla. The structures of 1 and 2 were elucidated by NMR and MS spectroscopic analysis. The relative stereochemistry of 1 was determined by single-crystal X-ray diffraction.

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Aim: Studies on synthesis and antibacterial activity of new heterocycles.

Methods: The cyclocondensation of [(3-pyridyl)-1,3,4-oxadiazol-2-yl] thio acetic acid with various aroyl hydrazines in the presence of POCl3 and xylene gave the corresponding titled compounds, and the in vitro antibacterial activity was primarily evaluated by the method of cupplate diffusion solution.

Results: Sixteen novel titled compounds were synthesized, their structures were confirmed by IR, 1HNMR, MS and elemental analysis.

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