A new polyphenol, 1, 3-di-O-caffeoyl-5-O-(1-methoxyl-2-O-caffeoyl-4-maloyl)-quinic acid, isolated from cultured cells of Saussurea involucrata / 中国天然药物

The present study was designed to isolate the polyphenol constituents of cultured cells of Saussurea involucrata. The polyphenol type constituents were isolated using chromatography methods, and then characterized by spectral analysis. 1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)-hydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) free radical scavenging were assayed using Vitamin C as the positive control. One new polyphenol 18, 1, 3-di-O-caffeoyl-5-O-(1-methoxyl-2-O-caffeoyl-4-maloyl)-quinic acid, together with 17 known compounds, was isolated and characterized. In conclusion, Compound 18 was a new caffeoyl maloyl quinic acid type polyphenol and showed desired vitro anti-oxidant activity. Compounds 1-5, 9, 10, 14, 15, and 17 were isolated from cultured cells of Saussurea involucrata for the first time.

Synthesis and biological activities of beta-chain fragments of hemoglobin / 药学学报

To investigate the angiotensin I-converting enzyme (ACE) inhibitory activity of beta-chain hemoglobin fragments, 17 fragments were synthesized by microwave-assisted solid-phase synthesis method. Wang resin or Trt(2-Cl) resin, Fmoc and HBTU-HOBt were used as solid carrier, N-terminal amino acid protecting groups and coupling reagents, respectively. The ACE inhibitory, alpha-glucosidase inhibitory, antibacterial and antitumor activities of the synthesized fragments were assayed. In vitro, Val-Val-Tyr-Pro-Trp-Thr showed high ACE inhibitory activity (IC50 = 7.42 micromol x L(-1)). The results indicate that there are two active sites in Val-Val-Tyr-Pro-Trp-Thr-Gln-Arg-Phe, one consists of Val-Val-, and the other -Gln-Arg-Phe. Peptides showed high ACE inhibitory activity when the N-terminal was hydrophobic amino acid such as Val and C-terminal tripeptide contained Phe, Trp or Arg. Some of the fragments showed low a-glucosidase inhibitory activity. No antibacterial activity or antitumor activity was detected in vitro. The results indicate that these peptides have a potential antihypertensive effect and possible application in the treatment of hypertension.