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).
Cylindradines A and B: novel bromopyrrole alkaloids from the marine sponge Axinella cylindratus.
The novel alkaloids cylindradines A and B were isolated from Axinella cylindratus, and their structures were elucidated by spectroscopic analyses. Stereochemistries of these compounds were determined by X-ray analysis. Cylindradines showed moderate inhibitory activity against the murine leukemia cell line P388.
THE IRON-ACETOCARMINE METHOD OF FIXING AND STAINING CHROMOSOMES
A short description of this procedure was given in Vol. 55 of the American Naturalist, pp. 573â€”574. The method has now been used almost daily for five years, and certain improvements have suggested themselves. The solution can be prepared by mixing about equal volumes of glacial acetic acid and water. To this is added powdered carmine in excess. The liquid is then â€ ? just brought to boil, cooled, and decanted. To the red solution there are then added a few drops of a solution of ferric hydrate in 50 per cent. acetic acid, to act as a mordant. The amount of iron varies with different objects. Too much produces a precipitate in a short time. The more