Discovery of novel VEGFR-2 inhibitors embedding 6,7-dimethoxyquinazoline and diarylamide fragments

VEGF/VEGFR-2 signaling plays a critical part in tumor angiogenesis. Inhibition of this pathway has been considered as a promising approach for cancer treatment. In this work, a series of 6,7-dimethoxy-4-anilinoquinazoline derivatives bearing diarylamide moiety were designed, synthesized and evaluated as potent inhibitors of VEGFR-2 kinase. Their in vitro antiproliferation activities against two human cancer cell lines Hep-G2 and MCF-7 have also been determined. Among them, compound 14b exhibited the most potent inhibitory activity against VEGFR-2 with IC₅₀ value of 0.016 ± 0.002 µM and it showed the most potent antiproliferative effect against Hep-G2 and MCF-7 with IC₅₀ values at low-micromolar range. Molecular docking studies revealed that these compounds represented by the most potent compound 14b could bind well to the ATP-binding site of VEGFR-2, which suggested that compound 14b could be a potential anticancer agent targeting VEGFR-2.

Characterization and comparison of transgenic Artemisia annua GYR and wild-type NON-GYR plants in an environmental release trial

The anti-malarial drug, artemisinin, is quite expensive as a result of its slow content in Artemisia annua. Recent investigations have suggested that genetic engineering of A. annua is a promising approach to improve the yield of artemisinin. In this study, the transgenic A. annua strain GYR, which has high artemisinin content, was evaluated in an environmental release trial. First, GYR plants were compared with the wild-type variety NON-GYR, with regard to phenotypic characters (plant height, crown width, stem diameter, germination rate, leaf dry weight, 1000-seed weight, leave shape). Second, stress resistance in the two varieties (salt, drought, herbicide, and cold resistance) was evaluated under different experimental conditions. Finally, gene flow was estimated. The results indicated that there were significant differences in several agronomic traits (plant height, stem diameter, and leave dry weight) between the transgenic GYR and NON-GYR plants. Salt stress in transgenic and control plants was similar, except under high NaCl concentrations (1.6%, w/w). Leaf water, proline, and MDA content (increased significantly) were significantly different. Transgenic A. annua GYR plants did not grow better than NON-GYR plants with respect to drought and herbicide resistance. The two varieties maintained vitality through the winter. Third, gene flow was studied in an environmental risk trial for transgenic GYR. The maximum gene flow frequency was 2.5%, while the maximum gene flow distance was 24.4 m; gene flow was not detected at 29.2 m at any direction. Our findings may provide an opportunity for risk assessment in future commercialization of transgenic A. annua varieties.

Comparison of extraction methods of total microbial DNA from freshwater

The demand for molecular analysis of aquatic microbial communities in freshwater has highlighted the need for efficient methods of DNA extraction. The centrifugation method and filtration-membrane method are 2 widely used methods for extracting DNA. The objective of this study was to compare the extraction efficiency of 3 methods, including the centrifugation method, filtration-membrane method, and modified filtration-membrane method, by evaluating the quantity and purity of DNA extracts obtained from water. DNA extraction was analyzed by agarose gel electrophoresis, ultraviolet-spectroscopy, restriction enzyme digestion, and polymerase chain reaction. The results showed that the modified filtration-membrane method was the most efficient for extracting microbial DNA from freshwater with high integrity and purity and is suitable for molecular applications.