No abstract

A new series of betulin derivatives containing one or two pharmacophores bearing an acetylenic and carbonyl function at the C-3 and/or C-28 positions has been synthesized and characterized by 1H- and 13C-NMR, IR, MS and elemental analyses. The crystal structure of 28-O-propynoylbetulin was determined by X-ray structural analysis. All new compounds, as well as betulin, were tested in vitro for their antiproliferative activity against human SW707 colorectal, CCRF/CEM leukemia, T47D breast cancer, and against murine P388 leukemia and Balb3T3 normal fibroblasts cell lines. Most of the compounds showed better cytotoxicity than betulin and cisplatin used as reference agent. 28-O-Propynoylbetulin was the most potent derivative, being over 500 times more potent than betulin and about 100 times more cytotoxic than cisplatin against the human leukemia (CCRF/CEM) cell line, with an ID50 value of 0.02 μg/mL.

For the first time, Raman spectroscopy has been employed to investigate formation of cross-links in collagen and porcine pericardium tissue upon glutaraldehyde (GA) treatment. GA treatment causes a very high fluorescence background, which overlaps Raman bands. It has been found that short fixation time, i.e. 2 h, reduces background radiation significantly, providing new possibilities for studying changes in molecular structure of collagen upon GA modification. The observed changes in position and intensity of Raman bands allowed us to recognize different types of GA-collagen interactions. Strong spectral evidence has been found for the peptide contribution to the formation of the GA-collagen cross-links and for the formation of secondary amines via Schiff base intermediates, and pyridinium-type cross-links. The results also revealed that different hydration levels and a more complex structure of intact tissue in comparison to collagen preparation strongly influence the formation of a GA cross-linking network, e.g. ether-type bond is preferred to form in a less hydrated collagen preparation. Our results have shown that GA treatment causes an increase in water content of pericardium tissue and collagen.

Jastrzębska, M, Kaczmarczyk, M, and Jastrzębski, Z. Effect of vitamin D supplementation on training adaptation in well-trained soccer players. J Strength Cond Res 30(9): 2648-2655, 2016-There is growing body of evidence implying that vitamin D may be associated with athletic performance, however, studies examining the effects of vitamin D on athletic performance are inconsistent. Moreover, very little literature exists about the vitamin D and training efficiency or adaptation, especially in high-level, well-trained athletes. The purpose of the current study was to investigate the effect of vitamin D supplementation on training adaptation in well-trained football players. The subjects were divided into 2 groups: the placebo group (PG) and the experimental group (SG, supplemented with vitamin D, 5,000 IU per day). Both groups were subjected to High Intensity Interval Training Program. The selection to the groups was based on peak power results attained before the experiment and position on the field. Blood samples for vitamin D level were taken from the players. In addition, total work, 5, 10, 20, and 30 m running speed, squat jump, and countermovement jump height were determined. There were no significant differences between SG and PG groups for any power-related characteristics at baseline. All power-related variables, except the 30 m sprint running time, improved significantly in response to interval training. However, the mean change scores (the differences between posttraining and pretraining values) did not differ significantly between SG and PG groups. In conclusion, an 8-week vitamin D supplementation in highly trained football players was not beneficial in terms of response to High Intensity Interval Training. Given the current level of evidence, the recommendation to use vitamin D supplements in all athletes to improve performance or training gains would be premature. To avoid a seasonal decrease in 25(OH)D level or to obtain optimal vitamin D levels, the combination of higher dietary intake and vitamin D supplementation may be necessary.