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Kidyu K Thaisuchat H Meepowpan P Sukdee S Nuntasaen N Punyanitya S Pompimon W 《Natural product communications》2011,6(8):1069-1072
A new clerodane diterpenoid has been isolated from the acetone extract of bulbils of Dioscorea bulbifera. The structure of compound 1 was established as 15,16-epoxy-6alpha-O-acety1-8beta-hydroxy- 9-nor-clero-13(16),14-diene-17,12;18,2-diolide on the basis of comprehensive spectroscopic techniques. 相似文献
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Pumsalid K Thaisuchat H Loetchutinat C Nuntasaen N Meepowpan P Pompimon W 《Natural product communications》2010,5(12):1931-1934
Chromatographic separation of the ethyl acetate extract of roots of Polyalthia cerasoides has led to the isolation of the new compound, 6,8-dihydroxy-7-methoxy-1-methyl-azafluorenone. This compound exhibited potent cytotoxic activities with IC50 values in the range of 2.64-3.58 microg x mL(-1) for A549, GLC4 and GLC4/Adr cells, but was not recognized by ABCC1/MRP1 protein. The compound also showed very strong inhibition of M. tuberculosis using a broth microdilution method, with an MIC value of 0.78 microg x mL(-1), which was equal to that of ofloxacin, one of the four antibiotic drugs used as a positive control. 相似文献
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In this report, we aimed to extend our previous efforts toward the evaluation of sulfonamides (SAs) with a boron-doped diamond (BDD) electrode. We improved this method by reducing the analysis time using a monolithic column coupled with amperometric detection to determine seven sulfonamides (sulfaguanidine, sulfadiazine, sulfamethazine, sulfamonomethoxine, sulfamethoxazole, sulfadimethoxine and sulfaquinoxaline). Because of its rapid separation, low back-pressure and high separation efficiency compared to a particle-packed column, a monolithic column (100 mm × 4.6 mm) was used for sulfonamide separation. Chromatographic separation was performed in less than 8 min. The analysis was carried out using phosphate buffer (0.1 M, pH 3): acetonitrile: methanol in a ratio of 80:15:5 (v/v/v) as the mobile phase with a flow rate of 1.5 mL min−1. The optimal detection potential using hydrodynamic voltammetry was found to be 1.2 V versus Ag/AgCl. The method was applied to determine seven sulfonamides in shrimp after sample preparation by solid-phase extraction. The recoveries of the sulfonamides in spiked shrimp samples at 1.5, 5 and 10 μg g−1 were in the range of 81.7 to 97.5% with a relative standard deviation (R.S.D.) between 1.0 and 4.6%. Our methodology produced results that were highly correlated with HPLC-MS data. Therefore, we propose a method that can be used for the rapid, selective and sensitive evaluation of sulfonamides in contaminated food. 相似文献
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