The effects of reactant ratio and reaction conditions on the compn. of the products are detd. for the esterification of maleic anhydride and monoglycerides of satd. fatty acids. The concn. of monoesters is higher in products prepd. in a closed reactor, compared with products compared in an open reactor. The compn. of the reaction product is varied as desired by appropriate selection of the temp., reaction time, and ratio of reactants. [on SciFinder(R)]

A review with 57 refs. [on SciFinder(R)]

Sorbitan esters of several fatty acids were analyzed by high-pressure liq. chromatog. (HPLC) using an Lichrosorb RP-18 column (25 cm × 4.6 mm). No derivatization was necessary. Mono-, di- and trisorbitan esters of palmitic, stearic, oleic, isostearic, and sesquioleic acid were sepd. using iso-PrOH-water (85:15, 80:20, or 92:8) as the elution mixt. [on SciFinder(R)]

Multiple emulsions of H2O-in-oil-in-H2O (W/O/W) were used to overcome the unpleasant taste of drugs such as chlorpromazine-HCl [69-09-0]. The drug was dissolved in the inner H2O phase and was released throughout the oil phase in the presence of synthetic gastric juice. Inner (I) and outer (II) emulsifiers were used. A combination of anionic-nonionic emulsifiers such as 8 wt.% Brij 93 [9004-98-2] as I and 3 wt.% Span 20 [1338-39-2] + Tween 80 [9005-65-6] + triethanolamine oleate [2717-15-9] as II (anionic-nonionic 1:4) gave high yield of prepn., high stability and complete release of drug in synthetic gastric juice. [on SciFinder(R)]

Product evolution upon hydrogenating 3 diene derivs. of p-(Me3C)2C6H4 (I) is compared with the formation of 1,4-di-tert-butylcyclohexene (II) and cis- (III) and trans-1,4-di-tert-butylcyclohexane from I on a Rh/Al2O3 catalyst to det. which diene(s), upon adsorption on the catalyst, best represent(s) the structure of the intermediate formed in the rate-detg. surface reaction of I. Of the dienes 1,4-di-tert-butyl-1,4- (IV) and -1,3- (V) and 2,5-di-tert-butyl-1,3-cyclohexadiene (VI), VI exhibits best the properties expected if it forms the same absorbed intermediate as I at the same H pressure. Unlike I, however, the dienes do not yield the cis-satd. isomer III as an initial product at low H pressures. Instead cis-3,6-di-tert-butylcyclohexene (VII) is formed, along with II and I; the dienes tend to exclude the cycloalkenes from the catalyst, their effectiveness increasing in the order IV \textless V \textless VI. At low pressures, \textless5% of I is transformed directly to III; instead, II and VII are produced initially. Because the concn. of the intermediate adsorbed dienes remains low during I hydrogenation, the cis ene VIII is converted rapidly to III in the presence of I. [on SciFinder(R)]

Results of a prospective study of response to phosphate treatment after surgery in a group of kidney stone formers, some of them recurrent are presented. The follow-up, of 1 year duration, was carried out by periodic tests of the stone formers' urine using the Discriminating Index (DI) procedure. In a group of 32 stone formers, 30 individuals showed a remarkable change in the DI value; i.e., the inhibiting potential of their urine was similar to that of normals. Two of the patients did not respond well, and their drug treatment was adjusted accordingly. During this year no recurrency was reported.[on SciFinder (R)]

It has been found that calcium oxalate stone formers have low UGOT and UGPT activity compared to healthy individuals. The urine of 23 stone formers and 19 controls has been tested for combined UGOT and UGPT activity. The effect of L-aspartic acid, alanine and L-glutamic acid on calcium oxalate precipitation has been tested. Only L-glutamic acid exerted a significant retardation effect at physiological concentrations. As GPT and GOT convert alanine and aspartic acid respectively into glutamic acid, a possible mechanism of retardation of kidney stone formation involving enzyme steps via glutamic acid creation in situ is suggested.[on SciFinder (R)]

It has been found that calcium oxalate stone formers have low UGOT activity compared to healthy individuals (controls). Urine from stone formers with no GOT activity and no effect on calcium oxalate precipitation was incubated with GOT for various periods. Subsequently calcium oxalate precipitation was decreased and found to be considerably retarded i.e., the pathological urine after the incubation acted in a way similar to that of normal urine. The yield of Glutamic-Oxalacetic Transaminase (GOT) activity is glutamic acid. It was shown that glutamic acid has a significant retardation effect on the precipitation of calcium oxalate stone formation. Therefore it may be suggested that GOT activity involved in glutamic acid creation in situ, has a role in kidney stone formation.[on SciFinder (R)]

Brominated surfactants are prepd. by the complete bromination of the double bonds in the hydrophobic chains of the oleic acid [112-80-1], linoleic acid [60-33-3], Span 80 [1338-43-8], Span 85 [26266-58-0], Tween 80 [9005-65-6], and Tween 85 [9005-70-3]. The addn. of Br increases the sp. gr. of the surfactant mol. to values above that of water, allowing the formation of oil-in-water emulsions with denser droplets, i.e., the surfactants are emulsifiers and weighting agents. The surfactant properties of the brominated surfactants are discussed. [on SciFinder(R)]

Stability of water-in-paraffinic oil (w/o) emulsions was studied using turbidity measurements of dild. systems at 400 and 800 nm. The method is most suitable for detn. of the required HLB, amt. and type of emulsifier, and the inner water phase fraction. The technique is in a good correlation with other known methods. [on SciFinder(R)]