Search

The heronapyrroles A–C have first been isolated from a marine-derived Streptomyces sp. (CMB-0423) in 2010. Structurally, these natural products feature an unusual nitropyrrole system to which a partially oxidized farnesyl chain is attached. The varying degree of oxidation of the sesquiterpenyl subunit in heronapyrroles A–C provoked the hypothesis that there might exist other hitherto unidentified metabolites. On biosynthetic grounds a mono-tetrahydrofuran-diol named heronapyrrole D appeared a possible candidate. We here describe a short asymmetric synthesis of heronapyrrole D, its detection in cultivations of CMB-0423 and finally the evaluation of its antibacterial activity. We thus demonstrate that biosynthetic considerations and the joint effort of synthetic and natural product chemists can result in the identification of new members of a rare class of natural products.

Introduction: Breast cancer is one of the leading causes of cancer death in women. Variations in the BRCA1, BRCA2, CDH1, STK11 and TP53 genes increase the risk of developing breast cancer. In addition to specific genetic changes, environmental factors may influence an individual’s risk of developing breast cancer. Lead is one of the most dangerous chemicals in the air as well as many products, such as cosmetics. Therefore, this study aimed to evaluate BRCA1 gene mutations in 9 rats receiving different doses of lead in the lipstick, compared to the control group. Materials & Methods: In this case-control study, 12 female Wistar rats with mean weight of 250 g were randomly divided into 4 groups of control (1) and the rats receiving low (2), average (3) and high doses (4) of lead in lipstick according to the measurements by the American Food and Drug Administration. Groups 2, 3, and 4 received lead acetate in their drinking water for 2 months on a daily basis. Afterward, DNA from blood samples was extracted and the BRCA1 gene was amplified using polymerase chain reaction (PCR) method. All PCR products were sequenced to investigate the genomic changes. Ethics code: IR.UMZ.REC.1397.48 Findings: The results of the sequencing showed no nucleotide changes in the BRCA1 sequences in the experimental and control groups. Discussion & Conclusions: According to the results, none of the doses of lead in lipstick change the BRCA1 gene. There may have been changes in other parts of the gene that have not been investigated in this study. Moreover, it is also possible that the same amounts of lead in the long run cause changes in the gene sequence.

Chemical fractionation of a southern Australian marine sponge, Trachycladus laevispirulifer, yielded 9-(5′-deoxy-5′-thio-β-d-xylofuranosyl)adenine disulfide as the first recorded natural occurrence of a nucleoside disulfide, and only the second of a xylo-nucleoside. Structure elucidation of the disulfide was achieved by detailed spectroscopic analysis and comparison to synthetic model compounds. The antibacterial, antifungal, and anticancer properties of the disulfide are documented and the literature surrounding natural and synthetic thionucleosides is reviewed. [ABSTRACT FROM AUTHOR]