Twenty-two new esters of natural (-)-cephalotaxine with synthetic acids possessing widely divergent structural features have been synthesized. Murinichloroethyl carbonate (27) esters of cephalotaxine are the most active of this group; this activity is less than that of harringtonine and other naturally occurring cephalotaxine esters. Other synthetic esters exhibiting activity are methyl cephalo...

The abuse of esters of natural androgenic steroids in cattle fattening and sports is hard to control via routine urine testing. The esters are rapidly hydrolysed in vivo into substances which are also endogenously present in urine. In veterinary control strange findings of 17beta-testosterone and 17alpha-testosterone in urine are often ignored because of the lack of statistically sound referenc...

Temperature-dependent techniques (differential scanning calorimetry, polarizing microscopy, and x-ray scattering and diffraction techniques) were used to compare the properties of human plasma low density lipoproteins (LDL) with its extracted lipid classes. Three types of thermal transitions were characterized: (a) a reversible transition in intact LDL near body temperature associated with a li...

Part A I. General methods S1-S2 II. Synthesis of boronate esters (Table 1) S3-S6 III. Competition studies (Table 1) S7 IV. Synthesis of haloboronate esters (Scheme 1) S8-S13 V. Selective Suzuki-Miyaura coupling with haloboronate esters (Table 2) S14-S18 VI. Deprotection of boronate esters (Table 2) S19-S22 VII. Total synthesis of ratanhine (Scheme 3) S23-S39 Part B VIII. NMR spectra Part C IX. ...

Three types, esters, amides and 1,2,3-triazoles, of ferrocenyl-podophyllotoxin conjugates were synthesised, and their anticancer activity was evaluated. We observed that the most potent ferrocenyl derivatives were esters. Esters 15, 16 and 17 acted in a similar way to podophyllotoxin, i.e. reduced the number of G1 phase cells and induced G2/M blockage, while esters 14 and 18 and amide 19 blocke...

This review is concerned with lipase catalyzed synthesis of sugar fatty acid esters in water immiscible organic solvents. Sugar esters are widely used nonionic and nontoxic biosurfactants. Certain sugar esters inhibit microbial growth and have other activities. Lipase mediated synthesis has important advantages over conventional chemical synthesis of sugar esters. Lipase catalyzed synthesis is ...

7alpha- and 7beta-hydroxycholesteryl esters, 7-ketocholesteryl esters, and 5,6alpha- and 5,6beta-epoxycholesteryl esters have been identified in tissues of patients affected by Wolman's disease. Their structural identities were determined by mass spectroscopy and nuclear magnetic resonance spectroscopy and confirmed by chemical synthesis. It is postulated that cholesteryl ester hydrolase defici...

Coenzyme A esters of all-trans- and 13-cis-retinoic acid were synthesized for use in studying vitamin A metabolism. The esters were obtained by two different synthetic methods starting from retinoic acids, which were converted to activated succinimidyl esters or anhydrides. These in turn were coupled with coenzyme A to form their respective thioesters. The retinoyl coenzyme A esters were purifi...

The choline esters potentiated the choline-catalysed decarbamoylation of dimethylcarbamoyl-acetylcholinesterase in proportion to the length of acyl group, although esters containing an acyl chain longer than the hexanoyl group exhibited a corresponding decrease in the potentiation. In structural requirement analysis it was found that both the quaternary ammonium moiety and the ester bond were i...

Methyl sterculate was rearranged by use of 0.5% of rhodium catalyst to isomeric conjugated diene fatty acid methyl esters containing both methyleneand methyl-branched isomers. The rearranged products were hydrogenated directly to saturated, methyl-substituted, branched-chain fatty acid methyl esters with the methyl substituent at one of the positions formerly occupied by the cyclopropenoid ring...