Chiroptical analysis of marine sponge alkaloids sharing the pyrrolopyrazinone core.

A systematic experimental study has been conducted on the chiroptical properties of bi- and tricyclic pyrrolopyrazinones, which occur as the core in a variety of marine pyrrole-imidazole alkaloids, such as the immunosuppressive palau'amine. On the basis of the chiral-pool synthesis of conformationally fixed dipyrrolopyrazinones, it was possible to predict the CD spectrum of (-)-dibromophakellin above 240 nm. 2,2,2-Trifluoroethanol was identified as a superior solvent for this analysis.

[Short-term change in sural venous thrombosis in patients in surgical intensive care when anticoagulants are contraindicated].

Venous thrombo-embolic disease in neurosurgical and surgical intensive care units is a frequent disorder (between 4.3 and 43 per cent of patients according to studies). The treatment is often difficult.