Emmyguyacins A and B: Unusual Glycolipids from a Sterile Fungus Species That Inhibit the Low-pH Conformational Change of Hemagglutinin A during Replication of Influenza Virus

Two novel glycolipids, emmyguyacin A (1a) and emmyguyacin B (1b), were isolated at concentrations of 1.51 g/L from a potato dextrose agar fermentation of a sterile fungus species. The compounds inhibit replication of influenza A virus (A/X31) in MDCK cells by inhibiting the pH-dependent conformational change of hemagglutinin A (IC50 9 μM). The structures were deduced using one- and two-dimensional NMR techniques and mass spectrometric analyses on both the parent compounds and a host of degradation products and derivatives. A novel and unusual oxalic acid ester of a monohydroxylated fatty acid (5, 17-oxalyloxydocosanoic acid) is reported. The first isolation and characterization of the fatty acid 17-hydroxydocosanoic acid (3) itself is also reported as a saponification product of 1

Discovery, Synthesis, and Insecticidal Activity of Cycloaspeptide E

Several Penicillia and one Tricothecium strain produced a new, insecticidally active member of the cycloaspeptide family, with the proposed name cycloaspeptide E (1). The structure, which was determined on the basis of spectroscopic (NMR, UV, MS) data and Marfey amino acid analysis, was the tyrosine desoxy version of cycloaspeptide A (2). Two synthetic routes to compound 1 were developed:  one a partial synthesis from 2 and the other a total synthesis from methyl alaninate hydrochloride. Cycloaspeptide E, the first member of this series not to contain a tyrosine moiety, is also the first to be reported with insecticidal activity