3,3',5,5'-Tetrabromophenolsulfonphthalein (bromphenol blue), C19H10Br4O5S

M r=670.02, monoclinic, C2/c, a= 31.003(4), b=11.037(2), c=21.183(3)A, fl= 143.7 (1) °, V= 4291.2/k 3, D,n = 2.06, D x = 2.07Mgm -3, Z=8, MoKa, 2=0.7107/k, /~=7.45 mm -1, F(000) = 2560, T= 293 K, R = 0.061 for 1697 observed reflections. The bromphenol blue molecule consists essentially of three planar groupings: the sulfonphthalein ring system and two dibromophenol rings attached to the tetrahedral C atom of the five-membered ring of the sulfonphthalein system. The dibromophenol rings are inclined with resPect to each other at 73 ° whereas they make angles of 85 and 68 ° with respect to the sulfonphthalein system. The molecules aggregate into helical columns with the non-polar regions of the molecules in the interior and the polar regions on the surface. The columns are held together by a network of hydrogen bonds.

A study of interaction between two He+ ions in terms of the electronic forces

The potential energy curve of the He2+2 system dissociating into two He+ ions is examined in terms of the electronic force exerted on each nucleus as a function of the internuclear separation. The results are compared with the process of bond-formation in H2 from the separated atoms.

In-plane normal vibrations of 1,2,5-oxa-, thia- and selena-diazoles, 1,3,4-oxa- and thia-diazoles and 1,2,3,4-thiatriazoles

In-plane vibration modes of 1,2,5- and 1,3,4-oxa- and thia-diazoles, and 1,2,5-selenadiazole have been assigned on the basis of detailed normal coordinate analysis employing data on several deuterated species. In-plane vibration frequencies of two 1,2,3,4-thiatriazole derivatives have been calculated and compared with observed values.

Examination of the role of FSH in periovulatory events in the hamster

he need for endogenous FSH in the periovulatory events such as oocyte maturation, ovulation, luteinization, maintenance of luteal function and follicular maturation was examined in the cyclic hamster. A specific antiserum to ovine FSH, shown to be free of antibodies to LH and to cross-react with FSH of the hamster, was used to neutralize endogenous FSH at various times. Administration of this antiserum during pro-oestrus did not affect oocyte maturation and ovulation, as judged by the normality of the ova to undergo fertilization and normal implantation. It also had no effect on the process of luteinization or on the maintenance of luteal function, as indicated by the normal levels of plasma and luteal progesterone during pro-oestrus and oestrus during the cycle and in pregnancy. All these processes were, however, disrupted by administration of an antiserum to ovine LH, thereby demonstrating their dependence on endogenous LH. Although FSH antiserum given at pro-oestrus did not prevent the imminent ovulation, it blocked the ovulation occurring at oestrus of the next cycle. This antiserum was effective in preventing the ensuing ovulation when given at any other time of the cycle until the morning of pro-oestrus. It is concluded that, in the hamster, high levels of FSH during pro-oestrus and oestrus are required for initiating maturation of a new set of follicles which are dependent on the trophic support of FSH throughout the cycle until the morning of pro-oestrus. Such follicles then appear to need only LH for subsequent ovulatory and associated processes.

Nucleotide sequence of the 3' terminal region of belladonna mottle virus-Iowa (renamed Physalis mottle virus) RNA and an analysis of the relationships of tymoviral coat proteins

The 3prime terminal 1255nt sequence of Physalis mottle virus (PhMV) genomic RNA has been determined from a set of overlapping cDNA clones. The open reading frame (ORF) at the 3prime terminus corresponds to the amino acid sequence of the coat protein (CP) determined earlier except for the absence of the dipeptide, Lys-Leu, at position 110-111. In addition, the sequence upstream of the CP gene contains the message coding for 178 amino acid residues of the C-terminus of the putative replicase protein (RP). The sequence downstream of the CP gene contains an untranslated region whose terminal 80 nucleotides can be folded into a characteristic tRNA-like structure. A phylogenetic tree constructed after aligning separately the sequence of the CP, the replicase protein (RP) and the tRNA-like structure determined in this study with the corresponding sequences of other tymoviruses shows that PhMV wrongly named belladonna mottle virus [BDMV(I)] is a separate tymovirus and not another strain of BDMV(E) as originally envisaged. The phylogenetic tree in all the three cases is identical showing that any subset of genomic sequence of sufficient length can be used for establishing evolutionary relationships among tymoviruses.

Structure of Sesbania mosaic virus at 3 angstrom resolution

Sesbania mosaic virus (SMV) is an isometric, ss-RNA plant virus found infecting Sesbania grandiflora plants in fields near Tirupathi, South India. The virus particles, which sediment at 116 S at pH 5.5, swell upon treatment with EDTA at pH 7.5 resulting in the reduction of the sedimentation coefficient to 108 S. SMV coat protein amino acid sequence was determined and found to have approximately 60% amino acid sequence identity with that of southern bean mosaic virus (SBMV). The amino terminal 60 residue segment, which contains a number of positively charged residues, is less well conserved between SMV and SBMV when compared to the rest of the sequence. The 3D structure of SMV was determined at 3.0 Å resolution by molecular replacement techniques using SBMV structure as the initial phasing model. The icosahedral asymmetric unit was found to contain four calcium ions occurring in inter subunit interfaces and three protein subunits, designated A, B and C. The conformation of the C subunit appears to be different from those of A and B in several segments of the polypeptide. These observations coupled with structural studies on SMV partially depleted of calcium suggest a plausible mechanisms for the initiation of the disassembly of the virus capsid.

A comparative study of the early effects of phenobarbital and 3-methylcholanthrene on the synthesis and transport of ribonucleic acid in rat liver.

At 2-3 h after phenobaribtal administration, the drug has no effect on nucleoplasmic RNA synthesis and decreases nucleolar RNA synthesis. However, at this time there is an increase in the labelling of cytoplasmic poly(A)-containing RNA, even though there is decreased labelling of total polyribosomal RNA. The decrease in labelling of nucleolar and total polyribosomal RNA owing to phenobarbital is a transient phenomenon. Under similar conditions, 3-methylcholanthrene has no effect on nucleolar RNA synthesis, but leads to an increase in synthesis of nucleoplasmic and cytoplasmic poly(A)-containing RNA. Cytosol isolated from phenobarbital-treated, but not from 3-methyl-cholanthrene-treated, animals facilitates an enhanced transport of RNA from nuclei. At the time points investigated, 3-methylcholanthrene or its metabolite shows a 10-15-fold higher concentration in the chromatin than that of phenobarbital or its metabolite. It is suggested that the primary effect of phenobarbital is at the cytoplasmic level, promoting the transport of RNA from the nuclei, which can act as a trigger for enhanced transcription at later periods. 3-Methylcholanthrene or its metabolite directly binds to the chromatin and evokes a selective transcriptional response.

Study of As2(Se,Te)3 glasses by X-ray absorption and photoelectron spectroscopy

Arsenic selenide-telluride glasses have been investigated by X-ray absorption and photoelectron spectroscopy. The core electron energy shifts and chemical shifts in K-absorption edge measurements associated with the glass-crystal transitions of pure As2Se3 and As2Te3 have been studied. The effect of composition on the core level energy and valence bands of As2(Se,Te)3 glasses, has been discussed. Mixed-composition glasses are found to be considerably ionic.

N-{1-[(3-Bromopropyl)aminocarbonyl]ethyl}-2-(2-nitrobenzenesulfonamido)propionamide

In the title compound, C15H21BrN4O6S, all three NH groups are involved in intermolecular N-H center dot center dot center dot O interactions which, together with two intermolecular C-H center dot center dot center dot O contacts, lead to a continuous antiparallel beta-sheet structure. There are no pi-pi interactions between molecules, and two C-H center dot center dot center dot pi interactions primarily govern the linkage between sheets.

4-Chloro-N-(3-chlorophenyl)benzamide

The title compound, C13H9Cl2N, has an intramolecular C-H center dot center dot center dot O close contact, and presents the NH group syn to the meta-chloro group in the aniline ring and trans to the C=O group. The crystal packing is formed by infinite chains of N-H center dot center dot center dot O hydrogen bonds along the c axis. Cl center dot center dot center dot Cl [3.474 (1) angstrom] contacts link chains. The crystal used for data collection was a twin, the domains related by the twin law 0.948 (1)/0.052 (1).

Ethyl 3-oxo-2-[(4-sulfamoylphenyl)hydrazono]butyrate

In the title compound, C12H15N3O5S, an intramolecular N-H center dot center dot center dot O hydrogen bond between the hydrazine unit and one of the carbonyl groups may influence the molecular conformation. In the crystal structure, intermolecular N-H center dot center dot center dot O hydrogen bonds, including one which is bifurcated, link the molecules into a two-dimensional network.

Ethyl 4-(4-hydroxyphenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carbox ylate monohydrate

In the title compound, C14H16N2O4 center dot H2O, the dihedral angles between the planes of the 4-hydroxyphenyl and ester groups with the plane of the six-membered tetrahydropyrimidine ring are 87.3 (1) and 75.9 (1)degrees, respectively. The crystal structure is stabilized by O-H center dot center dot center dot O and N-H center dot center dot center dot O hydrogen bonding between the water molecule and the organic functionalities.

Ethyl 4-(4-chlorophenyl)-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate

In the title compound, C14H15ClN2O2S, the tetrahydropyrimidine ring adopts a twisted boat conformation with the carbonyl group in an s-trans conformation with respect to the C C double bond of the six-membered tetrahydropyrimidine ring. The molecular conformation is determined by an intramolecular C-H center dot center dot center dot pi interaction. The crystal structure is further stabilized by intermolecular N-H center dot center dot center dot O molecular chains and centrosymmetric N-H center dot center dot center dot S dimers.

Voltage gated Na+ channels contribute to membrane voltage fluctuation in \alpha T3-1 pituitary gonadotroph cells

\alpha T3-1 cells showed a slope resistance of 1.8 G\omega. The cell membrane surface was not smooth and a scanning electron micrograph showed a complex structure with blebs and microvilli like projections. The cells showed spontaneous fluctuations at zero current resting membrane potential and hyperpolarization increased the amplitude of membrane potential fluctuations. The amplitude of membrane potential fluctuations at hyperpolarized membrane potential was attenuated on application of TTX to the bath solution. The potential at which half steady state inactivation of isolated sodium current occurred, was at a very hyperpolarized potential (-95.4 mV). The study presented in this paper shows that the voltage gated sodium channels contribute to the increase in the amplitude of electrical noise with hyperpolarization in \alpha T3-1 cells.

Synthesis and Evaluation of a Novel Class of G-Quadruplex-Stabilizing Small Molecules Based on the 1,3-Phenylene-Bis(piperazinyl benzimidazole) System

Achieving stabilization of telomeric DNA in G-quadruplex conformation by Various organic compounds has been an important goal for the medicinal chemists seeking to develop new anticancer agents. Several compounds are known to stabilize G-quadruplexes. However, relatively few are known to induce their formation and/or alter the topology, of the preformed quadruplex DNA. Herein, four compounds having the 1,3-phenylene-bis(piperazinyl benzimidazole) unit as a basic skeleton have been synthesized, and their interactions with the 24-mer telomeric DNA sequences from Tetrahymena thermophilia d(T(2)G(4))(4) have been investigated using high-resolution techniques Such as circular dichroism (CD) spectropolarimetry, CD melting, emission spectroscopy, and polyacrylamide gel electrophoresis. The data obtained, in the presence of one of three ions (Li+, Na+, or K+), indicate that all the new compounds have a high affinity for G-quadruplex DNA, and the strength of the binding with G-quadruplex depends on (1) phenyl ring substitution, (ii) the piperazinyl side chain, and (iii) the type of monovalent cation present in the buffer. Results further Suggest that these compounds are able to abet the conversion of the Intramolecular quadruplex into parallel stranded intermolecular G-quadruplex DNA. Notably, these compounds are also capable of inducing and stabilizing the parallel stranded quadruplex from randomly structured DNA in the absence of any stabilizing cation. The kinetics of the structural changes Induced by these compounds could be followed by recording the changes in the CD signal as a function of time. The implications of the findings mentioned above are discussed in this paper.