Staphylococcal enterotoxin types A and C, were observed by viscosimetry and near-ultraviolet difference spectroscopy to unfold at concentrations of aqueous guanidine hydrochloride greater than 1 M. Apparent rate constants of unfolding calculated from spectral curves differed markedly for the two enterotoxins. Rate constants for the unfolding of enterotoxin A in 2 or 3 M guanidine hydrochloride ...

The mechanism of guanidine-catalyzed enantioselective isomerization of 3-alkynoates to allenoates is investigated using density functional theory methods. The calculations predict that the isomerization reaction includes two hydrogen-transfer steps and one conformational change mediated by the TBO catalyst. The first hydrogen-transfer step corresponds to the migration of hydrogen from C(4) of t...

Infection of cells treated with guanidine and actinomycin D and then washed to remove the guanidine inhibition of virus growth had no effect on antiviral activity already established by interferon. Protein synthesis in interferon-treated cells infected under these conditions was decreased as compared to control cells similarly treated but not exposed to interferon. In these control cells, analy...

A set of small nonpeptidic diaryl phosphonate inhibitors was prepared. The phosphonate derivatives were synthesized through Birum-Oleksyszyn reaction followed by reduction of the nitro-group which undergo to Boc-protected guanidine derivatives. After removing of Boc-group by TFAA/DCM afford the guanidine phosphonates.

Polycyclic guanidine natural products, such as batzelladines A, E, and F, exhibit a rich and diverse array of interesting biological activities (Figure 1). Some polycyclic guanidine alkaloids have been shown to inhibit protein–protein interactions, including the binding of HIV gp120 to CD4 on human T-cells. Furthermore, many polycyclic guanidines display potent antiviral, antimalarial, and immu...

cDNA fragments representing the region in polypeptide 2C containing mutations in a guanidine-resistant or -dependent mutant were cloned into the wild-type background of an infectious clone. Transfection of COS-1 cells with these plasmids yielded viruses that were either completely resistant to 2.0 mM guanidine hydrochloride or dependent on this concentration of drug for growth.

In farms, Atlantic halibut (Hippoglossus hippoglossus) exhibit low appetite to formulated feeds, resulting in slow growth rate and feed wastage. Addition of attractants and/or stimulants in feeds may motivate them to actively feed in optimum quantities. In this study, olfactory and gustatory (facial) nerve responses to some feed-related chemical compounds were recorded. The olfactory thresholds...

A simple synthesis of cyclic guanidine derivatives is presented in this study. The construction of the central basic scaffolds is achieved by the application of microwave-assisted chemistry. This process completed without use of any extra reagent or protecting group manipulations. The formation of products of substituted guanidine was controlled by the temperature.

Novel guanidine-bisurea bifunctional organocatalysts 5 bearing a chiral pyrrolidine moiety on guanidine were designed with the guidance of DFT calculations. The resulting organocatalysts 5 were examined for α-hydroxylation of tetralone-derived β-keto esters, and good selectivity was obtained with 5j bearing a methoxymethyl ether-containing chiral pyrrolidine moiety.