Effect of chain length on the formation of intramolecular and intermolecular products: reaction of diols with cyclotriphosphazene

The reactions of cyclotriphosphazene, N3P3Cl6 (1), in a 1:1.2 stoichiometry with the sodium derivative of seven diols [ethane- (2a), 1,3-propane- (2b), 1,4-butane- (2c), 1,5-pentane- (2d), 1,6-hexane- (2e), 1,8-octane- (2f) and 1,10-decane- (2g) diol] in THF solution at room temperature have been used to investigate the effect of chain length on the formation of reaction products. Although no new products were found for the reaction of 1 with diols 2a–c compared to those in the literature using other bases and solution conditions, the reactions of 1 with the diols 2d–g gave six different types of products, whose structures have been characterized by elemental analysis, mass spectrometry, 1H and 31P NMR spectroscopy; ansa compounds N3P3Cl4[O(CH2)nO], (5d–5g); single-bridged compounds N3P3Cl5[O(CH2)nO]N3P3Cl5 (6d–6f); double-bridged compounds N3P3Cl4[O(CH2)nO]2N3P3Cl4 (7d–7g, syn and anti) and triple-bridged compounds, N3P3Cl3[O(CH2)nO]3N3P3Cl3 (8d–f). Where suitable single crystals were obtained, X-ray crystallographic studies confirmed the structures of two ansa compounds (5d and 5f), one single-bridged compound (6e), and five double-bridged compounds (meso-anti for 7d, 7e, 7f and meso-syn for 7d and 7f). 31P NMR measurements of the reaction mixtures were used to quantify the formation of products for the reactions 1 with all the diols, 2a–g; it is found that, with increasing chain length of the diol, there is a decrease in the products formed by intramolecular reactions (spiro and ansa derivatives) and a concomitant increase in the amounts of products formed by intermolecular reactions (single-, double- and triple-bridged derivatives) of cyclophosphazene

Formation of spiro and ansa derivatives in the reaction of 2,2,3,3,4,4-hexafluoropentane-1,5-diol with cyclotriphosphazene: Comparison with 2,2,3,3-tetrafluorobutane-1,4-diol

Reaction of cyclophosphazene, N3P3Cl6 (1), with the sodium derivative of the fluorinated diol, 2,2,3,3,4,4-hexafluoropentane-1,5-diol (2), in THF solution at room temperature afforded five isolated products, whose structures have been characterised by X-ray crystallography and 1H, 19F and 31P NMR spectroscopy: the mono-spiro compound, N3P3Cl4(OCH2CF2CF2CF2CH2O) (3), its ansa isomer (4), a di-spiro derivative N3P3Cl2(OCH2CF2CF2CF2CH2O)2 (5), its spiro-ansa (6) isomer and the tri-spiro compound N3P3(OCH2CF2CF2CF2CH2O)3 (7). Quantitative 31P NMR measurements of the soluble portion of the reaction mixture show that in the reaction of (1) with the sodium derivative of the fluorinated pentanediol (2) there is a small preference for spiro compounds compared to ansa compounds (ratio ca. 1.3:1), similar to the analogous reaction of (1) with the sodium derivative of the fluorinated butanediol where there is a slightly greater proportion of spiro compared to ansa compounds (ratio ca. 1.5:1). The relative proportions of spiro and ansa compounds is likely to depend on the fine balance in stabilities of the different medium-sized rings in the fluorinated pentanediol (spiro, 8- and ansa, 10-membered rings) compared to the fluorinated butanediol (spiro, 7- and ansa, nine-membered rings) derivatives of cyclophosphazene

Protective Effect of Vitamin E and Melatonin Against Radiation Induced Damage in Testes of Rats

To investigate the effects of vitamin E and melatonin on gamma ray induced damage in testes of rats. A total of 40 Wistar type rats were divided into 4 groups, each including 10 rats. Total body radiation was applied to the first 3 groups with 90 cm, 90% isodose curve using Cobalt 60 apparatus. The period of exposure time was 11 min 30 see and a total of 360 cGy gamma radiation was administered in each session. Following radiation exposure, intraperitoneal injection of vitamin E (100 mg/kg/day), melatonin (100 mg/kg/day), 0.9% saline (100 mg/kg/day) were done in group 1-3, respectively. Group 4 was the control group and intraperitoneal 0.9% saline (100 mg/kg/day) was administered without any radiation. Five days after the procedure testes were removed and analyzed to measure Malondialdehyde (MDA) levels and degree of histopathological injury. Tissue MDA level measured in rats receiving melatonin did not show significant difference when compared to control group (p>0.05). Similarly, there was no significant tissue injury on histopathological examination between melatonin administered and control groups. However, compared to the control group both tissue MDA level and tissue injury were found to be significantly increased in groups, which received vitamin E and 0.9% saline solution (p<0.05). Melatonin displays a remarkable tissue protective effect by inhibiting the damage mediated by free radicals after radiation. The same effect could not be obtained with Vitamin E. Thus, the cytoprotective effect of melatonin can be of value in preserving testicular functions after radiation exposure

Evaluating the effect of tumor size and sidedness on prognosis in stage 2 colon cancer: a retrospective population study

OBJECTIVE: In this study. we aimed to evaluate the effect of tumor size and tumor sidedness on prognosis in patients with stage 2 colon cancer