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Although there exists a variety of different catalysts for hydroboration of organic substrates such as aldehydes, ketones, imines, nitriles etc., recent evidence suggests that tetra-coordinate borohydride species, formed by activation, redistribution, or decomposition of boron reagents, are the true hydride donors. We then proposed that Me2S-BH3 could also act as a hydride donor for the reduction of various imines, as similar compounds have been observed to reduce carbonyl substrates. This boron reagent was shown to be an effective and chemoselective hydroboration reagent for a wide variety of imines.

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Vitamin E TPGS is a tocopherol (α-T) based nonionic surfactant that was used in the formulation of the Tocosol™ paclitaxel nanoemulsion, which was withdrawn from phase III clinical trials. Unlike tocopherols, however, the tocotrienol (T) isomers of vitamin E were found to have innate anticancer activity and were shown to potentiate the antitumor activity of paclitaxel. The primary objective of the present study was therefore to develop a paclitaxel nanoemulsions by substituting α-T oil core of Tocosol™ with γ-T in, and vitamin E TPGS with PEGylated γ-T as the shell, and test the nanoemulsions against Bx-PC-3 and PANC-1 pancreatic tumor cells. A secondary objective was to test the activity of paclitaxel when directly conjugated with the γ-T isomer of vitamin E. The synthesis of the conjugates was confirmed by NMR and mass spectroscopy. Developed nanoemulsions were loaded with free or lipid conjugated paclitaxel. Nanoemulsions droplets were <300 nm with fastest release observed with formulations loaded with free paclitaxel when γ-T was used as the core. Substituting α-T with γ-T was also found to potentiate the anticancer activity of the nanoemulsions. Although marginal increase in activity was observed when nanoemulsions were loaded with free paclitaxel, a significant increase in activity was observed when lipid conjugates were used. The results from this study suggest that the developed paclitaxel nanoemulsions with either γ-T, PEGylated γ-T, or paclitaxel lipid conjugates may represent a more promising option for paclitaxel delivery in cancer chemotherapy.

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Background: To investigate in vitro antioxidant, brine shrimp lethality bioassay, antimicrobial, anthelmintic activities and in vivo peripheral analgesic activity of methanol and petroleum ether extracts of Cassia renigera seed. Methods: Phytochemical screening of the crude extracts was carried out. Antioxidant activity was determined using seven different methods. Brine shrimp lethality bioassay and anthelmintic activities were done using nauplii of Artemia salina and adult earthworm (Pheretima posthuma), respectively. The antimicrobial potential was investigated against three Gram-positive and three Gram-negative bacteria. Acetic acid induced writhing test was performed to evaluate peripheral analgesic activity. Results: Both methanol and petroleum ether extracts showed the presence of flavonoids, saponins, and tannins. While alkaloids, glycosides, and steroids were only found in the methanolic extract. Methanolic extract showed more potent 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide scavenging capacity, cupric reducing and reducing power capacity than petroleum ether extract. While petroleum ether extract showed better results in total phenol and total antioxidant activities. In brine shrimp lethality bioassay methanolic and petroleum ether extracts showed the LC 50 value of 74.44 and 121.49 μg/mL, respectively. In overall antimicrobial study methanolic extract showed better activity than petroleum ether extract. Methanolic extract of 50 mg/mL showed maximum anthelmintic activity comparable to the standard (Piperazine Citrate, 10 mg/mL). Both 500 mg/kg and 1000 mg/kg body weight dose of the methanolic extract exhibited significant 39.64% and 58.73% writhing inhibition (< 0.05) in test animals, consecutively. Conclusions: In a nutshell, the results suggested that the seed can be used as a potential source for the aforesaid bioactivities.

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