This review summarizes the chemoenzymatic synthesis of the biologically active natural products based on a combination of chemical diastereoselectivity and enzymatic enantioselectivity using biocatalyst. Asymmetric reduction of 2-methyl-3-keto ester with yeast gave the optically active syn-2-methyl-3-hydroxy ester, which was converted to natural product such as (-)-oudemansin B. Asymmetric hydr...

Barium salts of dibenzylidene cystines 8a-c were obtained from the reaction of Lcystine with benzaldehyde or its derivatives in the presence of barium hydroxide. Their reduction with zinc and hydrochloric acid in methanol yielded the Narylmethylcysteines ?9a-c?. These can, in turn, be converted by esterification into the methyl esters ?10 a-c. ?Reaction of N, N'-carbonyl diimidazole (Im C...

An array of N-tosylated α-aminoalkylallenic esters was prepared and their cyclization under the influence of nucleophilic phosphine catalysts was explored. The α-aminoalkylallenic esters were prepared through aza-Baylis-Hillman reactions or novel DABCO-mediated decarboxylative rearrangements of allenylic carbamates. Conversion of these substrates to 3-carbethoxy-2-alkyl-3-pyrrolines was facilit...

Incubation of mature sweet corn kernels of Zea mays in dilute solutions of (14)C-labeled indole-3-acetic acid leads to the formation of (14)C-labeled esters of myo-inositol, glucose, and glucans. Utilizing this knowledge it was found that an enzyme preparation from immature sweet corn kernels of Zea mays catalyzed the CoA- and ATP-dependent esterification of indole-3-acetic acid to myo-inositol...

Twenty-four adult male African green grivet monkeys were fed diets containing 42% of calories as lard or menhaden oil and 0.76 mg of cholesterol/kcal for a period of 8 months. Plasma samples from fasting animals were then taken and low density lipoproteins (LDL) were isolated by ultracentrifugation and agarose column chromatography. The LDL were analyzed chemically, and physical properties of t...

There are several lines of evidence which suggest that the liver is a major source of plasma cholesterol esters. First, eviscerated rats cannot maintain a normal concentration of cholesterol esters in the plasma (1); second, when isotopically labeled mevalonic acid is administered to rats, the specific radioactivity of the hepatic cholesterol esters initially exceeds that of the plasma choleste...