Structure–activity relationship studies of atpenin A5 analogs with chemical modification of the side chain moiety

[Comprehensive Studies on the Synthetic Organic Chemistry of Unique Bioactive Natural Products; Total Synthesis, Drug Discovery, and Development of New Reactions]

Research on natural product chemistry via organic chemistry ranges from isolation and structural elucidation to total synthesis, drug discovery, and chemical biology. Discoveries in organic chemistry, such as novel reactions and synthetic strategies, are enabled by the studies of total synthesis. Thus, organic (synthetic) chemistry and natural product chemistry are correlated. We conducted comprehensive studies, including structure-activity relationship, drug discovery, and total synthesis studies, on the synthetic organic chemistry of natural products with unique biological activities and the development of novel reactions discovered through these products. This review describes the total synthesis of simpotentin, a novel potentiator of amphotericin B, and the development of the novel lactonization reactions of homopropargyl alcohols via intramolecular ketene trapping.

Micromonosporamide A with Glutamine-Dependent Cytotoxicity from Micromonospora sp. MM609M-173N6: Isolation, Stereochemical Determination, and Synthesis

An acyldipeptide, micromonosporamide A, was isolated from the fermentation broth of Micromonospora sp. MM609M-173N6 by bioassay-guided fractionation using a glutamine compensation assay. The planar structure was elucidated on the basis of comprehensive one- and two-dimensional nuclear magnetic resonance and high-resolution mass spectrometry. The relative and absolute configuration of the entire molecule were determined using a combined approach, involving chromatographic analysis by liquid chromatography-mass spectrometry, advanced Marfey's method, and total synthesis. Micromonosporamide A exhibited glutamine-dependent antiproliferative activity.