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101.
PE, one of the major phospholipids in oilseed soapstock, may react with gossypol to form Schiff bases. PE amounts to 20–30%
of the phosphorus compounds in soap-stock. In this report, the dependence on pH of the Schiff base products between PE and
gossypol was investigated using a spectrophotometer, an HPLC equipped with an ELSD, and an LC-MS system. We observed that
at pH 7 the Schiff reaction product and reactants were clearly detected by ELSD, absorption, and LC-MS spectra. The absorption
spectra displayed the characteristic peak for the Schiff bases around 430–440 nm. The absorption spectra also indicated that
the reaction was pH dependent. The reaction temperatures were 60 and 90°C. The LC-MS spectra supported the formation of Schiff
bases as well as methyl ether derivatives of gossypol in alcohol at the elevated temperatures. The implications of these experimental
findings are presented in this paper. 相似文献
102.
103.
Thermoplastic extrusion—the mechanism of the formation of extrudate structure and properties 总被引:6,自引:0,他引:6
Vladimir B. Tolstoguzov 《Journal of the American Oil Chemists' Society》1993,70(4):417-424
Systems processed by thermoplastic extrusion can be regarded as heterophase polymer melts of incompatible water-plasticized
biopolymers. In the process of thermoplastic extrusion, proteins and polysaccharides are melted at high pressure and temperature
below the temperature region of their thermal decomposition. Dispersed particles of these systems can be deformed in flow.
The mixed-melt anisotropic structure, formed in flow, is fixed by rapid conversion of the melt jet that lets the extruder
die from a viscous state to a rubber-like state and then to a glassy state caused by cooling and drying. Incompatibility of
proteins and polysaccharides in their water-plasticized melt mixtures impacts on structure formation and texturization during
thermoplastic extrusion.
Presented at the 20th ISF World Congress and 83rd AOCS Annual Meeting and Expo, May 10–14, 1992, Toronto, Ontario, Canada. 相似文献
104.
十二烷基苯磺酸钠水溶液聚集性质的研究 总被引:8,自引:0,他引:8
用滴体积法测出十二烷基苯磺酸钠(SDBS)稀水溶液的表面张力;然后求出其临界胶束浓度(CMC)。同时通过溶液的电导率、吸收光谱以及荧光光谱测定求出其CMC。这样测出的CMC值为1.2~1.6×10-3mol/L,与文献值相符。也研究了部分水解的聚丙烯酰胺(PHPAM)对SDBS聚集性质的影响;发现SDBS的CMC值随PHPAM的加人而减少并且PHPAM水溶液的粘度随SDBS的存在而急剧降低(类似盐效应)。这些方法与性质对强化采油(EOR)是重要的。 相似文献
105.
T. F Al-Fariss H. O. Ozbelge S. S. E. H Elnashaie S. M. AbdulRazik F. A. Abdel Aleem N. Gassem 《Nutrient Cycling in Agroecosystems》1991,28(2):201-212
This paper represents the first published report of a preliminary investigation of the possibility of using Saudi phosphate ores for the production of wet-process phosphoric acid. 相似文献
106.
非离子胶束对竹红菌乙素及其溴代物基态和激发态的保护作用 总被引:8,自引:0,他引:8
本文用Triton-X-100非离子型胶束增溶生红菌乙素及其两种溴代物,发现该胶束对HB的基态和激发态都有保护作用;(1)HB基态的ρKa升高;(2)荧光量子产率增大。这使其光敏反应产生的活性中间体^1O2和.OH的产额增加,从而增强了其光敏活性。 相似文献
107.
The oxidation of bulky thioethers has been carried out on Ti-Beta and Ti-MCM-41 catalysts, using H2O2 andt-butyl hydroperoxide (TBHP) as oxidants. The intrinsic activity of Ti-Beta was higher than that of Ti-MCM-41 for the oxidation of methyl phenyl sulfide which can penetrate in the pores of Beta, while in the case of the larger isopentyl phenyl sulfide, which diffuses more slowly in Ti-Beta zeolite, Ti-MCM-41 gives a larger activity. Ti-Beta is able to perform better for the more demanding oxidation of sulfoxides to sulfones giving, therefore, higher selectivities to sulfones than Ti-MCM-41. Similar results were obtained when using either H2O2 or TBHP as oxidants. However, the sterical effects were enhanced when TBHP was used as oxidant. 相似文献
108.
The micellar properties of aqueous binary mixed solutions for two systems consisting of sodium cholate (NaC)-octaoxyethylene
glycol mono n-decyl ether (C10E8) and sodium glycocholate (NaGC)-C10E8 have been studied on the basis of surface tensions, polarity of the micelle interior and the mean aggregation number. Application
of two theoretical treatments, based on regular solution and excess thermodynamic quantities for critical micellar concentration
(CMC) data from surface tension curves of two mixed systems showed that the mole fraction of each bile salt in the mixed micelles
near the CMC is lower than that of the corresponding prepared mole fraction in the mixed solution. The polarity of the interior
suggested that the hydrophobicity of intramicelles increased with the increase of the mole fraction of bile salt in the mixed
solution and that the mixed micelles become dramatically more hydrophobic at a mole fraction of 0.68 for NaGC−C10E8 system and 0.75 for NaC−C10E8 system, respectively. This implies that the micelles become richer in the bile salt molecules and the tendency appears strongly
for NaGC−C10E8 system due to the strong cohesion between the conjugated glycines in the NaGC molecules. The decrease of aggregation number
with the increase of the mole fraction of bile salts shows that the micelles approach those of the single system of each bile
salt. This supports the previously mentioned facts. 相似文献
109.
研究4种杀虫药物对盐生杜氏藻生长的致毒效应,结果表明:虫敌、纤源净、马拉硫磷、虫水安均不同程度上抑制盐生杜氏藻的生长繁殖,超过一定浓度后引起藻体的负增长,同时采用回归方程求出了4种药物对盐生杜氏藻24、48、72、96 h的半效应浓度EC50. 相似文献
110.
荧光法研究3种黄酮化合物与牛血清白蛋白的结合作用 总被引:2,自引:1,他引:1
运用荧光光谱法研究了生理酸度条件下(pH=7.4)3种黄酮化合物白杨素、芹菜素和桑色素与牛血清白蛋白(BSA)的结合作用。结果表明,3种黄酮化合物均能与BSA形成基态复合物导致BSA内源荧光猝灭,猝灭机理为静态猝灭。结合常数K(芹菜素)〉K(白杨素)〉K(桑色素),结合位点数近似等于1,白杨素与BSA之间以疏水作用为主,而芹菜素、桑色素与BSA之间的作用力主要是氢键和范德华力。黄酮分子结构中羟基位置及个数影响其与BSA间的结合作用,C4'-OH对结合有促进作用,而C3-OH的取代则导致作用力减弱。由Frster非辐射能量转移理论,计算出3种黄酮化合物在蛋白质中的结合位置与212位色氨酸残基间的距离分别为2.44 nm(白杨素)、3.34 nm(芹菜素)和3.31 nm(桑色素)。 相似文献