Synthesis, herbicidal activity study and molecular docking of novel pyrimidine thiourea.

According to the pharmacophore binding strategy and principle of bioelectronic isobaric, used the sulfonylurea bridge as the parent structure, a series of novel thiourea compounds containing aromatic-substituted pyrimidines were designed and synthesized. The preliminary herbicidal activity tests showed that some compounds had good herbicidal activity against Digitaria adscendens, Amaranthus retroflexus, especially for compound 4d and 4f. The results showed that compound 4d had an inhibition rate of 81.5% on the root growth of Brassica napus L. at the concentration of 100 mg L-1, and compound 4f had an inhibition rate of 81% on the root growth of Digitaria adscendens at the concentration of 100 mg L-1. Compounds 4d and 4f had higher comparative activity on Echinochloa crus-galli than the commercial herbicide bensulfuron-methyl. The preliminary structure-activity relationship (SAR) was also summarized. We also tested the in vivo AHAS enzyme activity inhibition experiment of 14 compounds at 100 mg L-1, and the results showed that they all have inhibitory activity on the enzyme, with the highest inhibition rate reaching 44.4% (compound 4d). Based on the results of molecular docking to yeast acetohydroxyacid synthase (AHAS), the possible herbicidal activity mechanism of these compounds was evaluated.

[In vivo Study of siRNA Silencing XIAP Gene to Reverse Taxol-resistance in Human Ovarian Cancer Cells].

OBJECTIVE: To study the relationship between down-regulated expression of X linked inhibitor of apoptosis protein (XIAP) gene and the reversal effect of taxol-resistance by using siRNA interference technology in the taxol-resistant ovarian cancer. METHODS: Randomly assigned the nude mice into six groups (6 in each group) . Group A: normal saline; Group B: taxol; Group C: siRNA-NC+normal saline; Group D: siRNA-NC+taxol; Group E: siRNA XIAP+normal saline; Group F: siRNA XIAP+taxol. Each group was dealt with the corresponding processing depending on the agreed protocol and the transplanted tumors had a multi-point injection with reagents related siRNA, one time every 3 days, 9 times (27 d) in total. Taxol (2 mg/kg) was used in the intraperitoneal injection, 0.2 mL every time, once a week, for four weeks. After 27 d of siRNA treatment, xenograft volumes and qualities were measured and the inhibitory rate was calculated; RNA expression levels and protein levels of XIAP gene in xenografts were detected respectively by real-time fluorescent quantitative PCR and Western blot. Apoptosis of the transplanted tumor cells was examined by TUNEL method. RESULTS: Among the six groups, the proliferation of transplanted tumor in Group F was the slowest, and the tumor inhibition rate was the highest compared with control Group A, followed by Group E, and the tumor inhibition rate was the lowest in Group C. Group F and E expressed the lowest XIAP mRNA and protein expressions ( P<0.05, vs. the other 4 groups) .The apoptosis rate was highest in Group F, followed by Group E, and lowest in Group A and C ( P<0.05). CONCLUSION: XIAP siRNA has synergy with taxol in taxol-resistant ovarian cancer cells.

[Study on the Relationship Between XIAP Gene and Resistance of Taxol in Ovarian Cancer].

OBJECTIVE: To research the expression of X-linked inhibitor of apoptosis protein gene (XIAP) on paclitaxel resistance in ovarian cancer. METHODS: A2780 and A2780/T cells were treated with paclitaxel respectively at the concentrations of 5 ng/mL,10 ng/mL,20 ng/mL , 40 ng/mL,80 ng/mL,160 ng/mL,320 ng/mL,then the inhibition rate of cells were detected by MTT assay. The expression of XIAP mRNA and protein among the A2780 and A2780/T cells treated respectively with paclitaxel at the concentration of 100 ng/mL was detected by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot. The A2780/T cells were divided into blank group,empty group,small interfering RNA (siRNA) XIAP group and siRNA-non-specific group. The expression of XIAP mRNA and protein of four groups were detected by RT-qPCR and Western blot. Apoptotic rate of these groups with addition of paclitaxel at the concentrations of 0 ng/mL,1 000 ng/mL,1 500 ng/mL,2 000 ng/mL and 2 500 ng/mL were detected by flow cytometry. RESULTS: After the treatments on A2780 and A2780/T cells with the different concentrations of paclitaxel,the inhibition rate of A2780 cells were gradually increased with the increased paclitaxel concentrations (P<0.05),while there were no obvious differences in A2780/T cells (P>0.05). After the treatment on these cells with paclitaxel at the concentration of 100 ng/mL,the expression of XIAP mRNA was lower than that non-treatment with paclitaxelin A2780 cells (P<0.05),and the expression of XIAP mRNA in the A2780/T cells were no statistical significance between the treatment group and non-treatment group with paclitaxel (P>0.05). However,the expression of A2780/T cells'XIAP mRNA and protein treated with paclitaxel were higher than A2780 cells' (P<0.05). The expression of XIAP mRNA and protein in siRNA-XIAP group was lower than those of other groups (P<0.05). The apoptotic rate of siRNA-XIAP group was higher than those of other groups treated with the paclitaxel at concentrations of 2 000 ng/mL and 2 500 ng/mL (P<0.05). CONCLUSION: XIAP's high expression on mRNA and protein was correlated with ovarian cancer paclitaxel-resistance,specific siRNA can promote cell apoptosis by reducing the expression of XIAP,and increase the sensitivity of drug-resistant cancer cells to paclitaxel.

[The Study of Decitabine Effect on the Endometrial Carcinoma Xenografted in Nude Mice.]

OBJECTIVES: To explore the effect of the demethylation drug 5-Aza-CdR on endometrial carcinoma xenografted in nude mice. METHODS: Randomly assigned the mice into decitabine (AZA),cisplatin (DDP),medroxyprogesterone acetate (MPA),AZA+DDP,AZA+MPA,DDP+MPA and model groups (three in each group) after building the models of xenografted tumor by transplanting the HEC-1B cells on nude mice,and dealt them respectively with corresponding drugs (1 µg/g,single or combination) in the experiment groups and normal saline in model group (injected per 3 d,8 injections in total).Then the tumor inhibitory rates in different groups were calculated.The methylation and protein expression of RASSF1A gene was estimated by methylation specific PCR (MSP) and Western blot respectively,and apoptosis situation of carcinoma cell was estimated by tunel. RESULTS: Inhibitory rate in AZA+DDP group was the highest,and the lowest was AZA group.RASSF1A gene promoter region methylation levels of AZA,AZA+DDP and AZA+MPA groups significantly reduced and showed obvious demethylation stripes while other groups mainly showed the methylation stripes.The differences of RASSF1A protein expression between AZA,AZA+DDP and AZA+MPA groups were not statistical significant (P>0.05),but the three were higher than model group (P<0.05);there was no statistically significant difference respectively in the DDP,MPA,DDP+ MPA groups compared with that of model group (P>0.05).In the comparison of apoptosis index,model group was the lowest,followed by the three single medicine groups,and the highest was three combination groups (P<0.05). CONCLUSIONS: Demethylation drug 5-Aza-CdR in endometrial cancer treatment has a great potential clinical application value by reversing the abnormal methylation of RASSF1A gene,restoring biological functions of RASSF1A protein and strengthening the efficacy of DDP and MPA.

Vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction for the determination of triazine herbicides in water samples by microemulsion electrokinetic chromatography.

A novel method based on the combination of microemulsion electrokinetic chromatography (MEEKC) and vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction (VSLLME) was developed for the determination of five triazine herbicides (simazine, atrazine, ametryn, prometryn, and terbutryn) in water samples. The five triazine herbicides were baseline separated by using the microemulsion buffer containing a 10 mmol/L borate buffer at pH 9.5, 2.5% (w/v) SDS as surfactant, 0.8% (w/v) ethyl acetate as oil phase, and 6.0% (w/v) 1-butanol as cosurfactant. The optimum extraction conditions of VSLLME were as follows: 100 µL chloroform was used as extraction solvent, 5.0 × 10⁻5 mol/L Tween-20 was chosen as the surfactant to enhance the emulsification, and the extraction process was carried out by vortex mixing for 3 min. Under these optimum experimental conditions, the calibration curve was linear in the range of 2.0-200.0 ng/mL, with the correlation coefficients (r²) varying from 0.9927 to 0.9958. The detection limits of the method varied from 0.41 to 0.62 ng/mL. The purposed method was applied to the determination of five triazine herbicides in real water samples, and the recoveries were between 80.6 and 107.3%.