A new lipopeptide, ciliatamide D (1), was isolated from a marine sponge Stelletta sp., collected at Oshimashinsone, together with the known compound ciliatamide A (2). Ciliatamide D (1) is a congener of 2, in which N-Me-Phe is replaced by N-Me-Met(O). Marfey's analysis of the acid hydrolysate of 1 demonstrated that the two constituent amino acids were both in the l-form. This result prompted us to carefully investigate the configuration of 2, resulting in the assignment of the l-form for both residues.

Yakushinamides A (1) and B (2), prolyl amides of polyoxygenated fatty acids, have been isolated from the marine sponge Theonella swinhoei as inhibitors of HDACs and SIRTs. Their planar structures were determined by interpretation of the NMR data of the intact molecules and tandem FABMS data of the methanolysis products. For the assignment of the relative configurations of the three contiguous oxymethine carbons in 1 and 2, Kishi's universal NMR database was applied to the methanolysis products. During the assignments of relative configurations of the isolated 1-hydroxy-3-methyl moiety in 1 and the isolated 1-hydroxy-2-methyl moiety in 2, we found diagnostic NMR features to distinguish each pair of diastereomers. The absolute configurations of 1 and 2 were determined by a combination of the modified Mosher's method and Marfey's method. Although the modified Mosher's method was successfully applied to the methanolysis product of 1, this method gave an ambiguous result at C-20 when applied to the methanolysis product of 2, even after oxidative cleavage of the C-14 and C-15 bond.

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We investigated the effects of electron-beam (EB) sterilization on syringe barrels manufactured from cyclo olefin polymer (COP). The chemical structure of the polymer was determined by interpreting the 13 C NMR and DEPT-135 spectra of the COP resin. The antioxidants in the resin were identified by analyzing the liquid chromatography-photo diode array-mass spectrometry (LC-PDA-MS) data for the methanol extract of the resin and the gas chromatography-mass spectrometry (GC-MS) data for the supercritical methanol degradation products of the extract. NMR and LC-PDA-MS analyses revealed that EB sterilization produces degradation products in the COP main chain and reduces the quantity of the antioxidants in the COP resin. ESR spectra of the EB-sterilized syringe barrels indicated the presence and location of alkyl radicals, which were generated in the COP main chain by EB sterilization. ESR analyses also indicated that the quantity of alkyl radicals decreased over time.

Two architecturally new isoquinolines, jasisoquinolines A and B, were isolated from a marine sponge Jaspis sp. as cathepsin B inhibitors. Their structures were determined by a combination of spectroscopic analyses and chemical methods. Both jasisoquinolines A and B inhibit cathepsin B with an IC(50) value of 10 μg/mL.