Group Dynamic Assessment in an Early Foreign Language Learning Program: Tracking Movement through the Zone of Proximal Development.

A phytochemical investigation on the 90% ethanol aqueous extract of the bulbs of Crinum latifolium led to the isolation of three new crinane-type alkaloids, designated as crinumlatines A-C (1-3). The structures of the new compounds were elucidated by spectroscopic analysis (NMR, IR, UV, and MS). The isolated alkaloids were tested in vitro for antimicrobial potentials against 5 pathogenic microorganisms. As a result, compounds 1-3 exhibited some antimicrobial activity against the tested Gram negative bacteria with minimum inhibitory concentration values less than 50 μg/ml.