Cycloartanes from the red alga Galaxaura sp.
Six cycloartane triterpenes have been isolated from the red alga Galaxaura sp. The new structures (galaxaurols A–E) were determined to be methyl 3β-hydroxy-23-oxocycloart-24-en-29-oate (2), methyl 23(E)-3β-hydroxy-25-methoxycycloart-23-en-29-oate (3), methyl 23(E)-3β-hydroxycycloarta-23,25-dien-29-oate (4), 23(E)-25-methoxycycloart-23-en-3β,29-diol (5), and cycloart-24-en-3β,23α,29-triol (6), respectively.
New cytotoxic cycloartane triterpene from Cassia italica aerial parts
Phytochemical study of the aerial parts of Cassiaitalica Mill. (family: Fabaceae) growing in Saudi Arabia afforded one new cycloartane triterpene, named (22E)-3-β-hydroxycycloart-22-en-24-one (2), together with eight known compounds: β-sitosterol (1), uvaol (3), daucosterol (4), methyl 3,4-dihydroxybenzoate (5), emodin (6), 4-hydroxypheny-O-β-D-glucopyranoside (7), aloin (8) and rutin (9). The structure of the isolated compounds was determined by physical, chemical and spectral data (UV, IR, MS, 1D (1H, 13C and DEPT) and 2D (1H–1H COSY, HSQC and HMBC) NMR), as well as by comparing with authentic samples. Compounds 3–5 and 7–9 were isolated for the first time from the plant. Compound 2 was evaluated for its cytotoxic activity against the L5178Y and PC12 cell lines. The total methanolic extract and compounds 5–9 exhibited free radical-scavenging activity using DPPH assay.
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