Axinellin A and B: Two New Pyrrolactam Alkaloids from Axinella sp.
Two new pyrrolactam alkaloids, axinelline A (1) and B (2), were isolated from the n-BuOH extract of marine sponge Axinella sp. The structures of these compounds were elucidated on the basis of spectroscopic methods (HR-ESI-MS, 1D and 2D NMR).
Studies on the chemical constituents of the South China Sea sponge Phacellia fusca
Three pyrrololactam alkaloids have been isolated from the marine sponge Phacellia fusca Schmidt collected from the South China Sea, and their structures were determined as 1–3, on the grounds of spectral data. This is the first report of these compounds from this sponge. The structure of 1 was confirmed by X-ray analysis.
Fifteen-minute acid hydrolysis of peptides.
Abstract During the last several years we have been using anaerobic and aerobic propionic acid/hydrochloric (HCl) hydrolysis as an analytical tool. Our previous communication (1) showed that not only free peptides but also peptides made by the Merrifield procedure (2–4) and still attached to the resin could be hydrolyzed quantitatively in 2 hr at 130°C. This procedure compared favorably (1) with constant boiling HCl hydrolysis which requires initial removal of the peptides from the resin and takes 24 hr. This publication compares the results of 55 peptides, 1 11 free and 44 attached to resin, hydrolyzed aerobically with propionic acid/hydrochloric acid for 15 min at 150°C, 15 min at 160°C, and 2 hr at 130°C.