An endophytic streptomycete (NRRL 30566) is described and partially characterized from a fern-leaved grevillea (Grevillea pteridifolia) tree growing in the Northern Territory of Australia. This endophytic streptomycete produces, in culture, novel antibiotics - the kakadumycins. Methods are outlined for the production and chemical characterization of kakadumycin A and related compounds. This antibiotic is structurally related to a quinoxaline antibiotic, echinomycin. Each contains, by virtue of their amino acid compositions, alanine, serine and an unknown amino acid. Other biological, spectral and chromatographic differences between these two compounds occur and are given. Kakadumycin A has wide spectrum antibiotic activity, especially against Gram-positive bacteria, and it generally displays better bioactivity than echinomycin. For instance, against Bacillus anthracis strains, kakadumycin A has minimum inhibitory concentrations of 0.2-0.3 microg x ml(-1) in contrast to echinomycin at 1.0-1.2 microg x ml(-1). Both echinomycin and kakadumycin A have impressive activity against the malarial parasite Plasmodium falciparum with LD(50)s in the range of 7-10 ng x ml(-1). In macromolecular synthesis assays both kakadumycin A and echinomycin have similar effects on the inhibition of RNA synthesis. It appears that the endophytic Streptomyces sp. offer some promise for the discovery of novel antibiotics with pharmacological potential.

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Assemblies of 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene (bbtz) and Co(NCS) 2 afford three supramolecular isomers [Co(bbtz) 2 (NCS) 2 ] n of square grid networks depending on the assembly conditions. Polymer transformation phenomena are observed among them. Conformation analysis of the ligand is presented to understand the flexibility of the bbtz ligand that influences the assembly topological architectures.

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The development of cancer in patients with schizophrenia is affected by genetic and environmental factors and antipsychotic medication. Several studies found that schizophrenia was associated with decreased risk of some cancers, and the neuroleptic medication might help to reduce the risk of colorectal cancer (CRC). Phenothiazine drugs including trifluoperazine (TFP) are widely used antipsychotic drugs and showed some antitumor effects, we here investigated the potential application of TFP in the treatment of colon cancer. A series doses of TFP were treated to the colon cancer cell line HCT116 and the inhibitory concentration (IC50) of TFP for HCT116 was determined by cell counting kit‐8. The results indicated that the treatment of TFP impaired the cell vitality of HCT116 in a dose‐ and time‐dependent manner. Meanwhile, the Edu assay demonstrated that the proliferation was also inhibited by TFP, which was accompanied with the induction of apoptosis and autophagy. The expression of CCNE1, CDK4, and antiapoptosis factor BCL‐2 was downregulated but the proapoptosis factor BAX was upregulated. The autophagy inhibitor chloroquine could significantly reverse the TFP‐induced apoptosis. Moreover, the ability of migration and invasion of HCT116 was found to be suppressed by TFP, which was associated with the inhibition of epithelial‐mesenchymal transition (EMT). The function of TFP in vivo was further confirmed. The results showed that the administration of TFP remarkably abrogated the tumor growth with decreased tumor volume and proliferation index Ki‐67 level in tumor tissues. The EMT phenotype was also confirmed to be inhibited by TFP in vivo, suggesting the promising antitumor effects of TFP in CRC.

The irrational use of antibiotics in agriculture and in the medical field has led to a variety of pathogenic microorganisms that produce drug resistance and even multidrug resistance. B-lactam is one of the most widely used antibiotics to treat infectious diseases. Resistance to β-lactam resistance can be primarily due to the presence β-lactamase, mutation of β-lactam targets and overexpression of efflux pumps. Two-component regulatory systems are composed of histidine kinase and response regulator that regulate gene expression under different environmental conditions. In this review, we summarized the mechanisms by which β-lactam resistance is developed and the role of the two-component regulatory system in β-lactam resistance.