[60]Fulleropyrrolidine-containing poly(benzyl ether) dendrimers 1-4 were synthesized via 1,3-dipolar cycloaddition of amino acid and aldehyde derivatives and [60]fullerene. Their dielectric and electrooptical (Kerr effect) solution properties were studied and compared with poly(propyleneimine) dendrimers, namely DAB-dendr-(alkyl chain)n and DAB-dendr-(CN)n, and with known symmetrical and non-sy...

In Salmonella enterica, 5-aminoimidazole ribonucleotide (AIR) is the precursor of the 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP) pyrophosphate moiety of thiamine and the last intermediate in the common HMP/purine biosynthetic pathway. AIR is synthesized de novo via five reactions catalyzed by the purF, -D, -T, -G, and -I gene products. In vivo genetic analysis demonstrated that in the abs...

A new series of pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine (PTP) derivatives has been developed in order to explore their affinity and selectivity profile at the four adenosine receptor subtypes. In particular, the PTP scaffold was conjugated at the C2 position with the 1-(3-trifluoromethyl-benzyl)-1H-pyrazole, a group believed to confer potency and selectivity toward the human (h) A2B ade...

A bacterium, Ochrobactrum anthropi, produced a large amount of a nucleosidase when cultivated with purine nucleosides. The nucleosidase was purified to homogeneity. The enzyme has a molecular weight of about 170,000 and consists of four identical subunits. It specifically catalyzes the irreversible N-riboside hydrolysis of purine nucleosides, the K(m) values being 11.8 to 56.3 microM. The optim...

Rat embryos (9.5 days gestation) were cultured for 48 h in heat-inactivated homologous serum containing [3-14C] serine. Analysis of the distribution of the radioactive label in the conceptus demonstrated that almost one half of the incorporated serine was cleaved to provide one-carbon units for the synthesis of purine and pyrimidine nucleotides. Analysis of the free amino acids in the serum, th...

The deboronation of enantiomers planar-chiral benzyl (3-formamido-1,2-dicarba-closo-dodecaboran-1-yl)acetate gave the individual (RP)- and (SP)-enantiomers (ee > 98%) a new amino acid containing nido-carborane fragment, (3-ammonio-7,8-dicarba-nido-undecaboran-7-yl)acetic acid. Chiral HPLC methods for analysis enantiomeric purity this compound was developed.

Hydrogen-bonded frameworks self-assembled from metal–nucleobase complexes and hexafluoro anions are reported by Wei Zhou, Zongbi Bao et al. in their Research Article (e202117609). Amino-rich ligands provide multiple H-bonding sites to stabilize the frameworks. In confined channels, electron-rich combined with electron-deficient purine rings generate a micro-electric field polarize lock Xe atoms...

Purine bias, which is usually referred to as an "ancestral codon", is known to result in short-range correlations between nucleotides in coding sequences, and it is common in all species. We demonstrate that RWY is a more appropriate pattern than the classical RNY, and purine bias (Rrr) is the product of a network of nucleotide compensations induced by functional constraints on the physicochemi...

The stimulation by yeast extract of acid production in milk by various lactobacilli was studied. It was found that supplementing milk with purine and pyrimidine bases and amino acids allowed nearly maximal acid production by Lactobacillus bulgaricus strain 7994, L. acidophilus 4796, 4356, and 4357, and L. leichmannii 326 and 327. Further supplementation with deoxyribotides allowed maximal acid ...

Nucleophilic addition of the chiral lithium enolates of (S)-(−)-4-benzyl-2-oxazolidinone acetamide with N-tosyl arylaldehyde imines gives -aryl-amino acid derivatives in good yields and excellent diastereoselectivity. © 2002 Elsevier Science Ltd. All rights reserved. -Amino acids and their derivatives have attracted considerable attention in recent years due to their occurrence in biologically ...