Synthesis and activities of derivatives of magnolol and honokiol / 中国药科大学学报

Based on the chemical structures of magnolol and honokiol,a series of small molecular derivatives were designed for the treatment of Alzheimer's disease.Through the Discovery Studio,five compounds (6a-6e) exhibited the inhibitory activity against Aβ and Tau proteins in all of the designed compounds.Then the five compounds are chemically synthesized and their biological activities were tested by thioflavin T.The result showed that compound 6a had inhibitory effect on the aggregation of two kinds of target proteins at the concentration of 100 μmol/L,which deserves further research.

Effect of quaternary ammonium carboxymethylchitosan on release rate in-vitro of aspirin sustained-release matrix tablets

The aim of this study was to develop a derivative of chitosan as pharmaceutical excipient used in sustained-release matrix tablets of poorly soluble drugs. A water-soluble quaternary ammonium carboxymethylchitosan was synthesized by a two-step reaction with carboxymethylchitosan [CMCTS], decylalkyl dimethyl ammonium and epichlorohydrin. The elemental analysis showed that the target product with 10.27% of the maximum grafting degree was obtained. To assess the preliminary safety of this biopolymer, cell toxicity assay was employed. In order to further investigate quaternary ammonium carboxymethylchitosan application as pharmaceutical excipient, aspirin was chosen as model drug. The effect of quaternary ammonium CMCTS on aspirin release rate from sustained-release matrix tablets was examined by in-vitrodissolution experiments. The results showed that this biopolymer had a great potential in increasing the dissolution of poorly soluble drug. With the addition of CMCTS-CEDA, the final cumulative release rate of drug rose up to 90%. After 12 h, at the grade of 10, 20 and 50 cps, the drug release rate increased from 58.1 to 90.7%, from 64.1 to 93.9%, from 69.3 to 96.1%, respectively. At the same time, aspirin release rate from sustained-release model was found to be related to the amount of quaternary ammonium CMCTS employed. With the increase of CMCTS-CEDA content, the accumulated release rate increased from 69.1% to 86.7%. The mechanism of aspirin release from sustained-release matrix tablets was also preliminary studied to be Fick diffusion. These data demonstrated that the chitosan derivative has positive effect on drug release from sustained-release matrix tablets

Cembranoid diterpenes from soft coral Sinularia sp / 中国中药杂志

A soft coral Sinularia sp., collected from the South China Sea, was selected to investigate the bioactive and chemical constituents. The EtOAc fraction were isolated by repeatedly silica gel and Sephadex LH-20 column chromatography to obtain lobophytolide A (1), 3-dehydroxylpresinularolide B (2), sarcophine (3), 3 beta-acetoxyisolobophytolide (4), Crassocolide D (5), (3E,7E,11E)-6-acetoxy-3,7,11,15(17)-cembratrien-16,14-olide (6). The structures of compounds 1-6 were determined on the basis of spectroscopic data analysis. All compounds were tested against a small panel of human tumor cell lines. And these compounds were obtained for the first time from this coral.