Results 221 to 230 of about 822,971 (285)

The structural properties of a noncentrosymmetric polymorph of 4-aminobenzoic acid

Acta Crystallographica Section C Structural Chemistry, 2014
The crystal structure of a polymorph of 4-aminobenzoic acid (PABA), C7H7NO2, at 100 K is noncentrosymmetric, as opposed to centrosymmetric in the structures of the other known polymorphs. The two crystallographically independent PABA molecules form pseudocentrosymmetric O—H...O hydrogen-bonded dimers that are further linked by N—H...O hydrogen bonds ...
El-Eulmi Bendeif, Radhwane Takouachet, Rim Benali-Cherif, Nourredine Benali-Cherif   +3 more
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Screening for cocrystals of succinic acid and 4-aminobenzoic acid

CrystEngComm, 2012
The ability of the pharmaceutically acceptable cocrystallising agents, succinic acid and 4-aminobenzoic acid, to form cocrystals with ten small organic molecules with hydrogen bonding acceptors but no donors, was investigated by grinding, hot-stage microscopy and solution based crystallisation experiments. The reproducible results obtained by different
Nizar Issa, Royston C. B. Copley, Sharmarke Mohamed, Doris E. Braun, Derek A. Tocher, Sarah A. Barnett, Sarah L. Price   +6 more
openaire   +3 more sources

A long lasting sunscreen controversy of 4-aminobenzoic acid and 4-dimethylaminobenzaldehyde derivatives resolved by ultrafast spectroscopy combined with density functional theoretical study.

Physical Chemistry, Chemical Physics - PCCP, 2020
4-Aminobenzoic acid (PABA) is one of the earliest patented and most commonly used sunscreen components. There is however a long-lasting controversy on its photo-protective efficacy owing to the lack of information on its protolytic equilibrium and photo ...
C. Chan, Chensheng Ma, Ruth Chau-Ting Chan, Hui-Min Ou, Han-Xin Xie, Allen Ka-Wa Wong, Ming-Liang Wang, W. Kwok   +7 more
semanticscholar   +1 more source

The Effects of Analyte Concentration on the Protonation Sites of 4-Aminobenzoic Acid Upon Atmospheric Pressure Chemical Ionization as Revealed by Gas-phase Ion-molecule Reactions.

Journal of the American Society for Mass Spectrometry, 2020
The most basic site of 4-aminobenzoic acid in aqueous solution is the amino nitrogen while the carbonyl oxygen is calculated to be the most basic site in the gas phase.
Rashmi Kumar, H. Kenttämaa
semanticscholar   +1 more source

The synthesis of 2‐mercapto‐4‐aminobenzoic acid

Recueil des Travaux Chimiques des Pays-Bas, 1951
AbstractThe synthesis of 2‐mercapto‐4‐aminobenzoic acid, a compound which is the sulphur analogue of p‐amino‐salicylic acid (2‐hydroxy‐4‐aminobenzoic acid), is described.
W. van Der Lugt, C. van der Stelt, W. Th. Nauta   +2 more
openaire   +2 more sources

Isoniazid and 4-aminobenzoic acid in the treatment of murine tuberculosis

Experientia, 1961
Bei der Mausetuberkulose war die kombinierte Therapie von Isoniazid mit 4-Aminobenzoesaure (PABA) (3 mg/Tag/Tier) wirksamer als diejenige von Isoniazid allein. Bei niedrigerer PABA-Dosis wurde der Synergismus nicht nachgewiesen.
Z. Šimáně, I. Reil, R. Urbančík, P. Kraus   +3 more
openaire   +3 more sources

Growth and characterization of an adduct 4-aminobenzoic acid with nicotinic acid

Journal of Crystal Growth, 2011
Abstract Synthesis, crystal growth of an adduct 2:1 4-aminobenzoic acid–nicotinic acid (AMN) and characterization are reported. The crystallographic data of the title compound are obtained from single crystal X-ray diffraction technique. The optical absorbance spectrum from 200 to 2250 nm shows the cutoff occurs at 490 nm.
T.S. Shyju, M. Rajalakshmi, R. Gopalakrishnan, S. Anandhi   +3 more
openaire   +2 more sources

Decarboxylation of substituted 4‐aminobenzoic acids in acidic aqueous solution

Recueil des Travaux Chimiques des Pays-Bas, 1967
AbstractRates of decarboxylation have been determined of the following substituted 4‐aminobenzoic acids 2‐H‐, 2‐CH3‐, 2‐Cl‐, 2‐Br‐, 2‐NO2‐, 2‐OH‐, 2‐OCH3‐, 3‐Br‐, 2,6‐(CH3)2‐, 2,6‐(C2H5)2‐, 2,6‐Cl2‐ and 2,6‐Br2‐ in aqueous hydrochloric acid solution (pH ranging from about 0 to about 2), at 50° and an ionic strength of 0.1 (except for the lowest pH ...
R. F. Rekker, C. H. T. Tonsbeek, J. M. Los   +2 more
openaire   +2 more sources

On the mechanism of increasing the tuberculostatic activity of isoniazid in the presence of 4-aminobenzoic acid [PDF]

Experientia, 1961
4-Acetaminobenzoesaure hatin vitro im Unterschied zu 4-Aminobenzoesaure, keinen gunstigen Einfluss auf die antituberkulotische Wirkung von Isoniazid. Bei den StammenMycobacterium 607 und H37Rv wurde jedoch chromatographisch keine Bildung acetylierter 4-Aminobenzoesaure nachgewiesen.
P. Kraus, R. Urbančík, Z. Šimáně
openaire   +2 more sources

The Azo Dye from 4‐Aminobenzoic Acid and Thymol – Proof of 4‐Aminobenzoic Acid as a decompostion product of Procaine

Archiv der Pharmazie, 1988
AbstractWir danken Herrn Prof. Dr. G. Zinner, Institut für Pharm. Chemie der Techn. Universität Braunschweig, für die Elementaranalyse. Herrn L. Schulte danken wir für seine gewissenhafte Mitarbeit.
Grigat H, Büsing G
openaire   +4 more sources