In this research we evaluated the calcium channel antagonist activity of various diester analohues of nifedipine on rat ileal smooth muscle.in these analogues,the orthophenyl group at position 4 was replaced by 1 methyl 2-meythylsulfonyl or methylthio 5-imidazolyl.wistar rats(180-250g) were killed by a blow to the head.the intestine was removed above the ileucecal junction and longitudinal smoo...

Conjugation of methotrexate (MTX) (MW 454) with different molecular weights of polyethylene glycol (PEG) including methoxy-peg (mpeg) 750 D and 5000 D and diol-peg 35000 D led to compounds that are physicochemically highly different from the parent compound, MTX. In this study, an HPLC system consisting of C8 column and UV detector (?=342 nm), using a mixture of 30:70 v/v phosphate-citrate buff...

A most effective and less energy demanding method of producing fatty esters, diol esters, by esterifying fatty acids, with neopentyl and ethylenglycol alcohols in the presence of an acidic ion exchange resin catalyst(polyestyrendivinylbenzensulfated) was investigated at elevated temperature. In this process an azeotroping agent, toluene, was used to facilitate continuous removal of water by dis...

dibutyl phthalate (dbp) is a phthalic acid ester and is widely used in polymeric products to make them more flexible. dbp is found in almost every plastic material and is believed to be persistent in the environment. various analytical methods have been used to measure dbp in different matrices. considering the ubiquitous nature of dbp, the most important challenge in dbp analyses is the contam...

background: phthalates are widely used as plasticizers in polyethylene terephthalate (pet) products. several pharmaceutical products have been stored in pet containers, and due to serious health effects of phthalates, migration levels of them into pharmaceutical products must be determined. in the present study, leaching levels of four common phthalate esters including di-n-butyl phthalate (dbp...

Analysis of MCPD esters and glycidyl esters in vegetable oils using the indirect method proposed by the DGF gave inconsistent results when salting out conditions were varied. Subsequent investigation showed that the method was destroying and reforming MCPD during the analysis. An LC time of flight MS method was developed for direct analysis of both MCPD esters and glycidyl esters in vegetable o...

subsequent to phytochemical investigation on scutellaria lateriflora (labiatae) from mazandaran provincein iran, the wax ester fraction of the leaves has been investigated. using tlc, cc glc and glc-ms, the alkyl esters of the epicuticular wax was analysed. total concentration of the esters was 35% and it was shown to be composed of a homologous series having various chain lengths in the range ...

The glycerolysis of methyl esters and triglycerides with crude glycerol. a coproduct from the transesterification of triglycerides, was studied. Three procedures were followed ior this conversion. The first procedure was a one-step glycerolysis with methyl esters. The second procedure was a two-step process. This proced~~re involved an initial partial glycerolysis with methyl esters, followed b...