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In this work, we isolated and characterized fusapyrone A (1), a new γ-pyrone derivative, along with six previously described compounds from the rice fermentation of Fusarium sp. CPCC 401218, a fung...

Ahmpatinin iBu (1) and statinin iBu (2), two new linear peptides, a novel pyrrolidine derivative, (−)-(S)-2-[3-(6-methylheptanamido)-2-oxopyrrolidin-1-yl] acetic acid (3), and three known pepstatin derivatives (4–6) along with their corresponding methanolysis artifacts (7–9) were isolated from Streptomyces sp. CPCC 202950. Their structures were elucidated on the basis of extensive spectroscopic data using Marfey's analysis, chiral-phase HPLC, and ECD and OR calculation to determine the absolute configurations. Compound 1 contains an unusual amino acid, 4-amino-3-hydroxy-5-(4-methoxyphenyl)pentanoic acid (Ahmppa), and 3 is the first natural product with a 2-(3-amino-2-oxopyrrolidin-1-yl)acetic acid system. Compounds 1, 2, and 4–9 are HIV-1 protease inhibitors. In particular, ahmpatinin iBu (1) exhibits significant inhibitory activity against HIV-1 protease with an IC50 value of 1.79 nM. A preliminary structure–activity relationship is discussed.

Isocoumarindole A (1), a novel polyketide synthetase-nonribosomal peptide synthetase (PKS-NRPS) hybrid metabolite, was isolated from the endolichenic fungus Aspergillus sp. CPCC 400810. The structure of isocoumarindole A (1) was featured by an unprecedented skeleton containing chlorinated isocoumarin and indole diketopiperazine alkaloid moieties linked by a carbon-carbon bond, which was determined by a combination of spectroscopic analyses, Marfey's method, and calculations of NMR chemical shifts, ECD spectra, and optical rotation values. Isocoumarindole A showed significant cytotoxicity and mild antifungal activities.