Erythromycin is produced by a strain of Saccharopolyspora erythraea (formerly Streptomyces erythraeus) and belongs to the macrolide group of antibiotics. It is basic and readily forms salts with acids but it is the base which is microbiologically active. Erythromycin base is (3R *, 4S *, 5S *, 6R *, 7R *, 9R *, 11R *, 12R *, 13S *, 14R *)-4[(2,6-Dideoxy-3-C-methyl3-O-methyl--L-ribo-hexopyranos...

Based on evidence from rodent models, it was hypothesized that furan fatty acids found in corn would inhibit reproduction in the laying hen. An isomeric mixture of furan fatty acids [9, (12)-oxy-10,13-dihydroxystearic acid and 10, (13)-oxy-9,12-dihydroxystearic acid] was administered for a period of 3 wk via the diet (1 and 3 ppm) at levels greater than those in corn to 20-wk-old pullets. There...

Four stereoisomers of oxy-peptide nucleic acids containing ether linkages in the main chain and conformationally-restricted pyrrolidine rings (pyrrolidine-based oxy-PNA = POPNA) were newly synthesized and investigated for binding to DNA. cis-l-POPNA with 9 adenine bases formed the most stable hybrid with dT(9). The POPNA showed high sequence specificity similar to that of the Nielsen-type PNA a...

Erythromycin is produced by a strain of Saccharopolyspora erythraea (formerly Streptomyces erythraeus) and belongs to the macrolide group of antibiotics. It is basic and readily forms salts with acids but it is the base which is microbiologically active. Erythromycin base is (3R *, 4S *, 5S *, 6R *, 7R *, 9R *, 11R *, 12R *, 13S *, 14R *)-4­ [(2,6-Dideoxy-3-C-methyl3-O-methyl--L-ribo-hexopyran...

Coupling reaction between electron-rich 2-morpholino-4(3H)-pyrimidinone and nucleophilic side chains of several natural α-amino acids promoted by phosphonium salt has been developed to prepare new optically active pyrimidin-4-yl amino acids. The best results were obtained using a two-step method through the easily available benzotriazolyl-1-oxy intermediate. A detailed optimization study of thi...

Decarboxylative cross-coupling of alkyl carboxylic acids with vinyl halides has been accomplished through the synergistic merger of photoredox and nickel catalysis. This new methodology has been successfully applied to a variety of α-oxy and α-amino acids, as well as simple hydrocarbon-substituted acids. Diverse vinyl iodides and bromides give rise to vinylation products in high efficiency unde...

This work describes a mild, environmentally friendly method to activate natural carboxylic acids for decarboxylative alkylation. After esterification of biomass-derived acids to N-(acyloxy)phthalimides, the active esters are cleaved reductively by photocatalysis to give alkyl radicals, which undergo C–C bond formation with electron-deficient alkenes. This reaction is catalyzed by the organic dy...

There is increasing international interest in naphthenic acids (NAs, classical formula C(n)H(2n+Z)O(2)) found in the oil sands from Alberta, Canada and in petroleum from around the world. The complexity of NAs poses major analytical challenges for their quantification and characterization. We used ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectr...