Studies Towards the Synthesis of the Core of Endiandric Acid H
In the presence of a CuBr·SMe2 catalytic system, a very simple and efficient approach for the synthesis of the key precursor of the core of endiandric acids starting from the readily and abundantly available 3-butyn-1-ol in five linear steps with an overall yield of 40% was developed.
Synthesis and biological evaluations of a series of calycanthaceous analogues as antifungal agents
Abstract Starting from indole-3-acetonitrile, a total of 66 new calycanthaceous alkaloid analogues were synthesised in excellent yields. The prepared compounds were evaluated for their biological activities against a broad range of plant pathogen fungi. The results of bioassays indicated that the majority of tested compounds displayed comparable or better in vitro bioactivities than the positive control. Notably, Compound a1 displayed a significant activities against B. cereus, Escherichia sp and R. solanacearum, even better than the positive control streptomycin and Penicillin, with the same MIC value of 15.63 µg mL−1. Compound a1 displayed a broad spectrum and remarkably activities among the tested calycanthaceous analogues and might be a novel potential leading compound for further development of antifungal agents. The results obtained in the study will be very helpful for further design and structural optimisation of calycanthaceous alkaloids as potential agrochemical lead for plant disease control. Graphical Abstract
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