Synthesis, Characterization and Antimicrobial Activity Study of Some New Substituted Benzoxazole Derivatives

This research included the preparation of 2-mercaptobenzoxazole (N1) by the reaction of ortho-aminophenol with carbon disulfide in an alcoholic potassium hydroxide solution. The 2-mercapto benzoxazole (N1) was then treated with hydrazine to obtain the 2-hydrazino benzoxazole (N2). A number of hydrazones (N3-N5) were prepared through the reaction of N2 with different benzaldehydes. The compound (N6) was also prepared whereby the ring closing of hydrazone (N3) using chloroacetylchloride, while the compound (N7) was prepared by treating 2-hydrazino benzoxazole with acetylacetone. When the compound (N1) was treated with formaldehyde, it afforded the compound (N8). Also, the N9 was obtained from the reaction of N1 with chloroacetic acid in the presence of alcoholic potassium hydroxide. The prepared compounds were characterized using physico-chemical and spectroscopic methods such as melting point, infrared spectroscopy (IR) and the proton nuclear magnetic resonance (1H-NMR). Thereafter, some of the compounds were selected for in vitro antibacterial activity and one of these compounds showed an inhibition effect against gram positive only which is very important because it is considered as specific antibacterial drug.

Simultaneous Determination of Vitamins D2 and D3 by Electrospray Ionization LC/MS/MS in Infant Formula and Adult Nutritionals: First Action 2012.11

A method was developed for the analysis of vitamins D2 and D3 in a variety of nutritional products. To extract vitamins D2 and D3 from products containing substantial amounts of fat, a saponification with alcoholic potassium hydroxide is required to release the vitamin D. Trideuterium- labeled vitamin D is added to the sample prior to saponification, and quantitation is achieved using linear regression of the ratio of peak response for 2H3-D and vitamin D. Acceptable linearity was achieved between 0.6 and 27 μg/100 g with a correlation requirement of >0.999. The method detection limit of 0.02 μg/100 g was verified by spiking placebo products carried through the saponification and extraction steps of the method. At the quantitation limit (0.12 μg/100 g), the signal was easily distinguished from the background. Vitamin D3 spike recoveries ranged from 107 to 119% at the low level and 104 to 116% at the high-level spike. Vitamin D2 recoveries were 105 to 116% and 91 to 110% for the low- and high-level spikes, respectively. SRM 1849a has a certified concentration of 11.1 ± 1.7 μg/100 g; using this standard reference material, the range of 9.4 to 12.8 μg/100 g was met on each of the 6 days. Method repeatability, determined in 12 vitamin D3 product matrixes over 6 days, ranged from 3.9 to 48%. The adult nutrition-milk protein sample was the most notable; it failed within-day, as well as day-to-day, precision requirements. There was no attempt to optimize the sample preparation to accommodate any problem matrix.