Subsidiary Dyes in Methylene Blue

Suitable tests have been devised for the detection of azure B (trimethyl thonin) and methylene violet in methylene blue. All samples of methylene blue examined have been found to contain appreciable proportions of azure B.     

Subsidiary Dyes in Methylene Blue

Suitable tests have been devised for the detection of azure B (trimethyl thonin) and methylene violet in methylene blue. All samples of methylene blue examined have been found to contain appreciable proportions of azure B.     

Structure elucidation and phytotoxicity of C13 nor-isoprenoids from Cestrum parqui

Twelve C(13) nor-isoprenoids have been isolated from the leaves of Cestrum parqui (Solanaceae). The structure (2R,6R,9R)-2,9-dihydroxy-4-megastigmen-3-one has been assigned to the new compound. All the structures have been determined by spectroscopic means and chemical correlations. The compounds showed phytotoxic effect on the germination and growth of Lactuca sativa L.     

Interactions of hydrated IIa and IIb group metal cations with thioguanine-cytosine DNA base pair: Ab initio and density functional theory investigation of polarization effects, differences among cations, and flexibility of the cation hydration shell.

The structures and energies of the thioguanine-cytosine Watson-Crick (thioGC WC) base pair interacting with hydrated IIa (Mg2+, Ca2+, Ba2+) and IIb group (Zn2+, Cd2+, Hg2+) cations have been studied using ab initio techniques. Furthermore, complexes between guanine and thioguanine with hydrated cations have been characterized assuming various structures of the hydration shells. The complexes of the thioGC WC base pair with hydrated cations have similar properties as the previously studied GC WC base pair. There is substantial polarization stabilization of the base pairing due to cation binding which amounts to 7 - 11 kcal/mol. Soft Cd2+ and Hg2+ cations have a uniquely strong interaction with the thiogroup and induce substantial nonplanarity of the pairing. The thiogroup tends to reduce the number of water molecules in the first hydration shell of the cation. All complexes were optimized within the Hartree-Fock (HF) approximation while their energetics has been evaluated using the second-order Moller-Plesset perturbational method (MP2). All interaction energy evaluations and a substantial portion of the optimizations of the hydrated cation-(thio)guanine complexes have been repeated using Becke-3LYP Density Functional Theory method. All three approximations used (HF, Becke-3LYP, and MP2) give qualitatively the same results for the present cationic complexes. The results demonstrate specific differences among the cations and provide a set of reference structures and energies for verification and/or parametrization of empirical potentials and other theoretical methods.     

Alpha-cycloPNA: 1-aminocylopentane-1-carboxylic acid-derived peptide nucleic acid

All four diastereoisomers of 3-thymine-1-((t)butoxycarbonyl)aminocyclopentane-1-carboxylic acid have been synthesised from (S)-dimethyl malate and thymine monomer 12 has been incorporated into an alpha-cycloPNA oligomer.     

Synthesis and biological activities of cyclic AMP analogs modified in the 1, 2, and 2′-positions

Analogs of adenosine-3′,5′-cyclic phosphate (cAMP) modified in positions 2 (Cl, Br, SCH₃) and 2′ (2,4-dinitrophenyl) and doubly modified in positions 1 and 2 (N¹O and Cl), 2 and 2′ (Cl and 2,4-dinitrophenyl), have been synthesized by convenient methods. These derivatives have been examined as alternative activators of cAMP-dependent protein kinase isolated from bovine muscle and as alternative substrates for a cyclic phosphodiesterase from bovine heart. All analogs activated the kinase, most of them being more effective than cAMP. All were degraded by the diesterase, several at lower rates.     

The synthesis and biological activity of lipophilic derivatives of bicine conjugated with N³-(4-methoxyfumaroyl)-L-2,3-diaminopropanoic acid (FMDP)-an inhibitor of glucosamine-6-phosphate synthase

A series of bis-N,N-(2-hydroxyethyl)glycine (bicine) derivatives, conjugated with an inhibitor of glucosamine-6-phosphate synthase, have been synthesized and their lipophilic and antifungal properties have been tested. The obtained compounds demonstrated higher lipophilicity than free inhibitor (FMDP) and, in consequence, an increased potential to cross the cytoplasmic membrane. All the tested compounds show better antifungal activity than parent compound.     

Purification of biomolecules by the method of adsorptional chromatography in the expanded bed. I. Principles of the method

Principles the Expanded Bed Adsorption (EBA) have been described in the survey. The paper also deals with critical operation parameters, principles of the method design and optimization, which will guarantee maximum operation of this unique operation stage. All these problems have been discussed. The survey is illustrated by the examples of various types of biological molecules which have been purified using EBA.     

Phloroglucinol derivatives of Hagenia abyssinica

Four phloroglucinol derivatives have been isolated from Hagenia abyssinica (Bruce) Gmel. The structure (IV) and partial structures (V), (VI) and (VII) are proposed. All are mixtures of isobutyryl (iB), isovaleryl (iV) and 2-methylbutyryl (2-MeB) side chain homologues. The two latter acyl groups have been detected for the first time in kousso.     

DNA metabolism during maturation of male germ cells. II. Amplification structures in the nuclei of rat germ and somatic cells

Amplification structures have been found in preparations of histone-depleted somatic (liver) and sex (spermatogonia, spermatocytes 1) rat cells. Multi-forked chromosomal (2-4 replicative forks originating from a single strand of DNA) and extrachromosomal circular amplification structures have been detected in the nuclei of sex cells. All the circular molecules of DNA detected belong, according to size, to the class of small nuclear polydispersed circular DNAs. Chromosomal amplification structures (eye-in-eye or several replicative forks originating from one DNA strand) have been only detected in the nuclei of somatic cells.     

Isolation and characterization of pLS 1 plasmid mutants with increased copy numbers

Abstract Streptococcus pneumoniae genetic systems designed for isolation of plasmid mutants with copy-up phenotypes have been developed. The target plasmids have the pLS1 replicon, and two different strategies have been followed: (i) selection of clones exhibiting augmented resistance to antibiotics, or (ii) obligatory co-existence of incompatible plasmids. We have isolated 23 plasmid mutants exhibiting increased number of copies. All the mutations corresponded to four different alleles of the copG gene of plasmid pLS1. These strategies could be used with other plasmids.     

Syntheses of polymeric vesicles containing partial structures of N-acetyl-muramyl-dipeptide (MDP)

The syntheses of 11-methacroylaminoundecanoyl-L-alanyl-D-isoglutamine (3) and 2-[2-(11-methacroylaminoundecanoyl)aminoethoxy]propanoyl-L- alanyl-D-isoglutamine (13) are described. Each of these monomers has been copolymerized with 11-methacroyloxyundecyltrimethylammonium bromide (16), yielding polymeric vesicles that contain partial structures of N-acetyl muramyl dipeptide (MDP). All products have been characterized by 1H- and 13C-NMR spectroscopy and the polymeric vesicles have been studied by electron microscopy. The potential use of these structures as immunostimulating products is discussed.     

Synthesis and antimicrobial evaluation of new chalcones containing piperazine or 2,5-dichlorothiophene moiety

Two new series of chalcones have been synthesized by reacting 1-(4-piperazin-1-yl-phenyl)ethanone and 1-(2,5-dichloro-3-thienyl)-1-ethanone with different substituted benzaldehydes in turn by Claisen-Schmidt condensation. The compounds have been characterized by IR, (1)H NMR spectral and microanalysis data. All the synthesized compounds have been evaluated for antimicrobial activity. Some of these derivatives are potentially active against Gram-positive bacteria, Staphylococcus aureus and Escherichia coli while the most potent compound (1) in this study showed MIC(50) value of 2.22 microg/mL against Candida albicans.     

Construction of restriction enzyme fragment libraries containing DNA from human adenovirus types 2 and 5

Restriction-fragment libraries containing adenovirus type 2 (Ad2) DNA have been constructed, using the pBR322 plasmid (Bolivar et al., 1977) as a vector. Clones have been isolated which contain all the HindIII fragments of Ad2 DNA except the terminal G- and K-fragments inserted into the HindIII cleavage site of the vector. All the 13 SmaI-fragments of Ad2 DNA were separately inserted into the PstI site of the pBR322 vector after addition of homopolymeric poly(dG) tails to the fragments and poly(dC) tails to the linearized plasmid. Two large fragments of adenovirus type 5 (AD5) DNA, located between map positions 17.0 and 59.5 and between map positions 59.5 and 97.3, respectively, were cloned using bacteriophage lambda as a vector. All clones, which are described in the present report, are available upon request.     

Summer annual plants exhibit germination responses to an aridity gradient consistent with both delayed germination and phenotypic plasticity

Plant Ecology - Two adaptive strategies to face variable environments have been proposed for annual plants in deserts: delayed and plastic (predictive) germination. All theories and models have...     

The separation and synthesis of lipidic 1,2- and 1,3-diols from natural phenolic lipids for the complexation and recovery of boron

A study has been made of the semi-synthesis of 1,3-diols (anacardic alcohols) from natural phenolic lipid resources from Anacardium occidentale and Anacardium giganteum which have given C15 and C11 derivatives, respectively. An isomeric 1,3-diol (isoanacardic alcohol) has been obtained from cardanol separated from technical cashew nut-shell liquid. Homologous 1,3-diols have been synthesised from a range of synthetic 2-alkyl-, 3-alkyl- and 4-alkylphenols and from 6-alkylsalicylic acids. The natural 1,2-diol, urushiol, from Rhus vernicifera has been purified. All these lipidic compounds have been studied for their complexation and the potential recovery of boron as boric acid.     

基于光学性质的纳米生物探针设计策略

纳米生物复合探针具有多功能复合、多检测路径、易于信号放大、制备简便等多种优越性。基于其优越的光学性质,人们可以利用常规光学设备实现生物检测,甚至可以实现目视检测。现就本实验室在光学纳米生物探针制备和应用的研究进展作一简要综述,所述纳米生物探针类型主要有:基于表面等离子体效应的纳米生物探针、基于量子效应的纳米生物探针和基于比表面效应的纳米生物探针,并介绍如何应用这些探针进行生物传感和生物芯片的构建。     

Sequential 1H-NMR assignment and solution structure of bovine pancreatic ribonuclease A

Assignments for 1H-NMR resonances of most of the residues of bovine pancreatic ribonuclease (RNase A) have been obtained by sequence-specific methods. Identification and classification of spin systems have been carried out by two-dimensional phase-sensitive correlated spectroscopy (360 MHz) and single relayed coherence transfer spectroscopy. Sequence-specific assignments have been achieved by phase-sensitive two-dimensional nuclear Overhauser effect spectroscopy. To overcome the problem of spectral overlap use has been made of (a) an exhaustive analysis of partly exchanged RNase A (spectra in D2O), (b) a comparison with the subtilisin-modified enzyme (RNase S) and (c) small spectral perturbations caused by changes in pH and temperature. The secondary structure elements have been identified from the observed sequential, medium and long-range nuclear Overhauser effects together with data from amide-exchange rates. All information collected leads to the conclusion that the crystal and the solution structures are closely similar.     

Synthesis of peptidyl ureas employing O-succinimidyl-(9H-fluoren-9-ylmethoxycarbonylamino) methylcarbamate derivatives as activated monomers

A convenient and efficient method for the synthesis of dipeptidyl ureas and urea acids employing O-succinimidyl-(9H-fluoren-9-ylmethoxycarbonyl amino)methylcarbamates has been described. All the compounds, obtained in good yields, have been fully characterized by mass and NMR spectra.     

A 3D model of the peripheral benzodiazepine receptor and its implication in intra mitochondrial cholesterol transport

A three-dimensional (3D) model of the peripheral benzodiazepine receptor (PBR) has been built using molecular dynamics simulations.The transmembrane domain of the receptor has been modeled as five alpha-helices, which are not long enough to cross the entire bilaver membrane hut correspond approximately to only one phospholipid layer. The receptor model has also been tested as a cholesterol carrier, and molecular dynamics simulations have shown that it could indeed accommodate a cholesterol molecule within the five helices. All three known PBR sequences have been modeled, and no significant difference has been found between them.