The presence of a remarkably high concentration of pteridiineS in the blue green alga, Anacystis nidulanis 5, wvas demonstrated by Forrest, van Baalen, and Myers in 1957 (2). A number of (lifferent pteridines were then isolated and ideentifie(l. These included 2-amino-4-hydroxypteridine, 2,6-diamino-4-hydroxypteridline (10), a yellow pteridine assigned the structure 2-aimino-4-hydroxv-6-propion...

Some new nitrogen bridge-head pyrido[1,2-b][1,2,4]triazepines incorporating 6methylchromone moiety have been synthesized from the reaction of 1,6-diamino-4-(6methyl-4-oxo-4H-chromen-3-yl)-2-oxo-1,2-dihydropyridine-3,5-dicarbonitrile (4) with some α,γ-bifunctional electrophiles including 2-cyano-3,3-bis(methylthio)acrylonitrile, 2cyano-3,3-bis(methylthio)prop-2-enamide, 5-chloro-3-methyl-1-pheny...

In the crystal structure of the title compound, C(4)H(7)N(4)O(+)·Cl(-)·2H(2)O, adjacent cations are connected to one another through N-H⋯O hydrogen bonds, forming infinite chains along the b axis. These chains are further hydrogen bonded to the chloride anions and water mol-ecules, resulting in a three-dimensional network. The pyrimidine rings of adjacent mol-ecules are arranged in an anti-para...

In the title salt, 2C4H6ClN4(+)·C4H2O4(2-), the complete fumarate dianion is generated by crystallographic inversion symmetry. The cation is essentially planar, with a maximum deviation of 0.018 (1) Å. In the anion, the carboxyl-ate group is twisted slightly away from the attached plane, the dihedral angle between the carboxyl-ate and (E)-but-2-ene planes being 12.78 (13)°. In the crystal, the ...

1,9-Diamino-5-azanonane (1, H2N(CH2)4NH(CH2)4NH2), symmetrical “homospermidine,” previously unreported in nature, has now been discovered in sandal (Santalum album L.), where it comprises 0.5-1.5% of the weight of the dried leaves. The new polyamine is conveniently isolated from an aqueous extract of the leaves by ion-exchange 1^) uring a routine examination of the amino acids from an ethanolic...

The kinetics of excision of damaged purine bases from oxidatively damaged DNA by Escherichia coli Fpg protein were investigated. DNA substrates, prepared by treatment with H2O2/Fe(III)-EDTA or by gamma-irradiation under N2O or air, were incubated with Fpg protein, followed by precipitation of DNA. Precipitated DNA and supernatant fractions were analyzed by gas chromatography/isotope-dilution ma...

The synthesis of 3-amino-1-nitroguanidine (3-ANQ) and 5-hydrazino tetrazole (5-HT) derivatives as new energetic materials are described. Reaction of 3-ANQ with triethyl orthoformate leads to the formation of 3-nitramino triazole while no reaction was observed whit 5-HT. Addition of NaN3 to a mixture of 3-ANQ and triethyl orthoformate, afforded 1-nitroguanidyl tetrazole in excelle...

A bis-bisurea receptor (L) based on the R,R-cyclohexane-1,2-diamino scaffold forms an uncommon 2 : 2 complex (1) with the monohydrogen phosphate ion (HPO(4)(2-)) and a 1 : 1 complex (2) with the sulfate ion (SO(4)(2-)). Solution binding properties of the two anions were studied by (1)H NMR, UV-vis, and circular dichroism (CD) methods.