Five isoflavanoids including one new, (3R)-2',4',5,7-tetrahydroxy-6-methylisoflavanone (1), were isolated from the aerial parts of Desmodium heterophyllum. Their structures were elucidated using spectroscopic methods. Their inhibitory effects on digestive enzymes α-glucosidase and α-amylase were evaluated. Genistein (5) and dalbergioidin (2) inhibited both enzymes. Their IC 50 values were found at 110.4 and 162.8 µM for α-amylase, and at 257.3 and 412.6 µM for α-glucosidase, respectively.
Twenty-five compounds were identified from the essential oil of Globba pendula Roxb. by gas chromatography–mass spectrometry (GC-MS) with Selinene<d-> (22.09%) as the main component, followed by Ishwarane (6.52%). The essential oil was found to possess moderate NO inhibitory effect with IC50 of 41.68 ±4.51 µg/ml, significant cytotoxic activity against MCF7 and Hep3B cell lines with IC50 of 28.15±1.08 and 35.24±0.06 (µg/ml), respectively. This is the first report on volatile compounds and biological activities of essential oil of Globba pendula Roxb. collected at An Giang province, Vietnam.
Flagellin FljB composes flagellar antigen (H:1,2) of S. Typhimurium. This kind of antigen increases immunogenicity of any conjugated antigen upon administration. Thus, it is supposed to have an enormous potentiality for vaccine development against bacterial infections and cancer diseases. fljB gene (1515 nucleotides) coding for mature FljB was amplified by PCR from genomic DNA of S. Typhimurium and inserted into pET32a(+) for expression in E. coli BL21. The protein FljB was well expressed under the fusion form with Trx, Stag at N terminal and hexahistidine at C terminal, thus the recombinant protein was abbreviated to TrxFljB. Study on the impact of temperature on the gene expression showed that TrxFljB was synthesized at lower level at 37 o C comparing to the levels at 22 o C and 25 o C. 13% of the protein synthesized at 37 o C was inclusion body. Lower temperatures used during induction phase increased the solubility of the recombinant protein. About 97% of TrxFljB synthesized at 25 o C was soluble. IPTG concentration had a strong effect on the growth of freshly transformed cells but did not affect on the growth of stored and re-cultivated cells. The increase of IPTG concentration resulted in the decrease of the growth of freshly transformed cells and the TrxFljB productivity. However, 0.05 mM IPTG concentration was found to gain the full TrxFljB expression. TrxFljB productivity declined during storage of cells at 4 o C and re-cultivation. At optimal condition, volumetric productivity of TrxFljB was about 300 mg/ l broth.
Maltooligosyltrehalose trehalohydrolase (MTHase) is an industrial enzyme for the production of trehalose. A DNA fragment of 1680 bp encoding for MTHase was cloned from Sulfobolus solfataricus DSM 1616 then fused with promoter acoA-amyE already amplified from pMSE3 vector by PCR to generate an expression cassette acoMTH. Afterward the cassette was inserted into pAC7 vector for expression of the gene in Bacillus subtilis WB800 – a conventional expression system. Gene MTH was inserted into the genome of B. subtilis WB800 by cross-exchange event of pAC7 vector with the host genome for expression of high quality and high quantity of extracellular recombinant protein. By crossing-exchange event at 3’amyE-5’amyE, the expressional cassette was integrated into B. subtilis WB800 genome. The expressional cassette was integrated into B. subtilis WB800 genome replacing 3’amyE-5’amyE, hindering the native amylase activity of the host. Expression of expected protein was confirmed by electrophoresis SDS-PAGE. From our results, it indicates that gene MTH was expressed successfully in B. subtilis WB800. After 0.5% acetoin induction for 48 h, the data showed that the protein with a molecular mass of ~64 kDa on SDS-PAGE was expressed. The level of recombinant protein in WBpAacoMTH was increased and reached 2.5%, 15.2% and 21.95%, respectively comparing with native B. subtilis WB800.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.