Although the antibiotic streptomycin was isolated and characterized a number of years ago, little knowledge has accumulated concerning its synthesis by Xtreptonzyces griseus. In I954 Numerof, Gordon, Virgona, and O’Brien (1) administered glycine and acetate labeled in either the carboxyl or the (Y carbon to cultures of X. griseus. A low extent of incorporation of 1% into the streptomycin synthe...

1. The effects of regeneration of whole bovine albumin on antigenic activity and serological specificity were determined by precipitin measurements on rabbit antisera to (1) native whole albumin, (2) albumin regenerated from 8 M urea, and (3) albumin regenerated from 8 M guanidine hydrochloride. 2. While numerically the mean antibody response to these three antigens was found to decrease in the...

A novel and mild Rh(III)-catalyzed [5+1] oxidative cycloaddition between arylguanidines and alkynes efficiently affords C4-disubstituted 1,4-dihydroquinazolin-2-amines. Members of this family of heterocycles, which contain the relevant cyclic guanidine units, have shown interesting pharmacological properties. The mechanism probably involves the formation of an eight-membered rhodacycle in which...

Guanidine applied to Nitella may lower the threshold of E.M.F. required to produce electrical stimulation and may give rise to trains of action currents. Its effect thus appears to be somewhat similar to that observed in animals. Rapid action currents are produced as well as "square topped" action curves and transitional forms. These effects may be due in part to increased protoplasmic conducti...

Ferrocytochrome b562 [Fe(II)cyt b562] folding can be triggered by photoinduced electron transfer to unfolded Fe(III)cyt b562 in 2-3 M guanidine hydrochloride solutions. The folding rates increase with decreasing guanidine hydrochloride; the extrapolated time constant for this folding process in the absence of denaturant (5 micros) is near the predicted value for intrachain diffusion. The relati...

A new approach for the stereoselective synthesis of the bicyclic guanidine alkaloid (+)-monanchorin has been developed using a palladium(ii)-catalysed MOM-ether directed Overman rearrangement to establish the second stereogenic centre and a cross metathesis reaction to generate the carbon backbone. In the final stage, a one-pot acid mediated deprotection of aldehyde, guanidine and hydroxyl grou...

Guanidine does not inhibit the translation of viral RNA into virus specific proteins but it seems to prevent the generation of functional viral polymerase from precursor material. In the presence of guanidine, "inhibitory protein (s) " responsible for the shut-off of cellular protein synthesis are still produced provided that the multiplicities of infection are high. The incoming (parental) vir...

A novel design as well as a straight-forward synthesis for a photoswitchable guanidine catalyst is reported. Intense studies of the photochromic properties demonstrated the reversible switchability of its photosensitive azobenzene moiety. Its activity in the ring-opening polymerization (ROP) of rac-lactide was investigated as well. The obtained results are discussed, and an additional guanidine...

Marine organisms are prolific resources of guanidine-containing natural products with intriguing structures and promising biological activities. These molecules have therefore attracted the attention of chemists and biologists for their further studies towards potential drug leads. This review focused on the guanidine alkaloids derived from marine sources and discussed the recent progress on th...