Novel Sulfonamide Derivatives Containing a Piperidine Moiety as New Bactericide Leads for Managing Plant Bacterial Diseases.

Plant bacterial diseases are an intractable problem due to the fact that phytopathogens have acquired strong resistances for traditional pesticides, resulting in restricting the quality and yield of agricultural products around the world. To develop new agrochemical alternatives, we prepared a novel series of sulfanilamide derivatives containing piperidine fragments and assessed their antibacterial potency. The bioassay results revealed that most molecules displayed excellent in vitro antibacterial potency towards Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas axonopodis pv. citri (Xac). In particular, molecule C4 exhibited outstanding inhibitory activity toward Xoo with EC50 value of 2.02 µg mL-1, which was significantly better than those of the commercial agents bismerthiazol (EC50 = 42.38 µg mL-1) and thiodiazole copper (EC50 = 64.50 µg mL-1). A series of biochemical assays confirmed that compound C4 interacted with dihydropteroate synthase, and irreversibly damaged the cell membrane. In vivo assays showed that the molecule C4 presented acceptable curative and protection activities of 34.78% and 39.83%, respectively, at 200 µg mL-1, which were greater than those of thiodiazole and bismerthiazol. This study highlights the valuable insights for the excavation and development of new bactericides that can concurrently target dihydropteroate synthase and bacterial cell membranes.

Matrine inhibits invasiveness and metastasis of human malignant melanoma cell line A375 in vitro.

BACKGROUND: Matrine is a traditional Chinese medicine with significant inhibitory activity against malignant tumors. Its effects on the invasiveness and metastasis of malignant tumors have rarely been reported. AIM: To investigate whether matrine can inhibit the metastasis-related activities of the human malignant melanoma cell line A375 in vitro. METHODS: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and Annexin-V-fluorescein isothiocyanate/propidium iodide (Annexin-V-FITC/PI) affinity assay were used to examine the effects of matrine on the proliferation and apoptosis induction of A375 cells. The morphologic changes of A375 cells were observed by light and electron microscopy. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were performed to evaluate the expression of heparanase mRNA and protein. The effect of matrine on the adhesion ability and invasiveness of treated A375 cells was tested by cell-Matrigel adhesion assay and Matrigel invasion assay, respectively. RESULTS: Matrine showed significant inhibition of the proliferation of A375 cells in a dose- and time-dependent manner. It also induced apoptosis in a dose-dependent manner. Compared with the control group, the levels of heparanase mRNA and protein expression of A375 cells treated with different concentrations of matrine were decreased significantly, as were their adhesion ability and invasiveness. CONCLUSIONS: These findings indicate that matrine inhibits the invasiveness and metastasis of A375 cells in vitro. The mechanisms may be linked to the inhibition of cellular proliferation, induction of apoptosis, and downregulation of heparanase mRNA and protein expression.

Identification of a novel mutation and a de novo mutation in DKC1 in two Chinese pedigrees with Dyskeratosis congenita.

Dyskeratosis congenita (DKC) is a rare and fatal congenital syndrome characterized by the triad of reticular skin pigmentation, nail dystrophy and mucosal leukoplakia, and the predisposition to bone marrow failure and malignancies. Mutations in DKC1 gene encoding dyskerin are responsible for the X-linked dyskeratosis congenita. Here we report mutation analysis of two Chinese pedigrees with dyskeratosis congenita. The 15 coding exons of DKC1 and their flanking regions were amplified from genomic DNA by PCR. DNA sequencing and restriction endonuclease digestion were used for mutation detection. Transition mutation of 1226C-->T (P409L) found in the first pedigree is a novel mutation. In the second pedigree, the proband's mother phenotypically normal carried a de novo transition mutation of 1058C-->T (A353 V) in one allele, and transmitted the mutant allele to her two sons who had typical manifestations of dyskeratosis congenita.