Physicochemical Properties of a New Multicomponent Cosolvent System for the pKa Determination of Poorly Soluble Pharmaceutical Compounds

2007 ◽  
Vol 90 (8) ◽  
pp. 1538-1553 ◽  
Author(s):  
Karl J. Box ◽  
Gergely Völgyi ◽  
Rebeca Ruiz ◽  
John E. Comer ◽  
Krisztina Takács-Novák ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Pharmaceutical Compounds ◽  
Poorly Soluble ◽  
Pka Determination

PHYSICOCHEMICAL PROPERTIES DETERMINATION OF PICROSIDE-II

INDIAN DRUGS ◽  
2019 ◽  
Vol 56 (08) ◽  
pp. 27-37
Author(s):  
S. Bhusari ◽  
A Chaudhary ◽  
G Shrangare ◽  
M. Rindhe ◽  
P. Wakte ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Linseed Oil ◽  
Angle Of Repose ◽  
Log P ◽  
P Value ◽  
Solubility Study ◽  
Picroside Ii ◽  
Compressibility Index ◽  
Pka Determination

The aim of the present study is to determine the physicochemical properties of Picroside-II, a phytochemical obtained from the herb of Picrorhiza kurroa. The solubility study of picroside-II shows that it has better solubility in water up to 2.46 mg/mL than organic solvents. The solubility of picroside-II in linseed oil was found to be 71.46 mg/mL. The solubility of Picroside-II in surfactant like Transcutol P and labrasol was found to be 907.80 and 535.90 mg/mL, respectively. Picroside-II had a melting point in the range of 130 to 135°C. The log P value of picroside-II was estimated using shake flask method followed by UV analysis. The log P value of picroside-II was found to be -0.09675, which shows its hydrophilicity. The pKa determination of picroside-II was carried out by using UV-visible spectrophotometer and the pKa value was found to be 7.80. The particle size distribution of picroside-II powder was also carried out and the maximum particles of picroside-II are in the range of 53-75 μm. Flow properties of picroside-II were also studied. bulk and tapped density of picroside-II powder was found to be 0.149 and 0.248, respectively. The Hausner ratio and compressibility index were also calculated and it was found to be 1.66 and 39.99, which confirm the poor flow properities of picroside-II powder. The angle of repose of picroside-II was found to be 41.08°, which shows the passable flow of picroside-II. Water was found to be the better extractive solvent for picroside-II; the extractive value of picroside-II in water was found to be 9.12%.

scholarly journals Determination of molar refractions and Abraham descriptors for tris(acetylacetonato)chromium(iii), tris(acetylacetonato)iron(iii) and tris(acetylacetonato)cobalt(iii)

2017 ◽  
Vol 41 (23) ◽  
pp. 14259-14265 ◽  
Author(s):  
Michael H. Abraham ◽  
William E. Acree ◽  
Anthony F. Fucaloro ◽  
Andrew W. Zanella
Keyword(s):  
Physicochemical Properties ◽  
Chemical Properties

Descriptors for tris(acetylacetonato) complexes of Cr(iii), Fe(iii) and Co(iii) can be used to assess chemical properties of the complexes and to predict numerous physicochemical properties.

scholarly journals pKa Determination of a Histidine Residue in a Short Peptide Using Raman Spectroscopy

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 405 ◽  
Author(s):  
Brett H. Pogostin ◽  
Anders Malmendal ◽  
Casey H. Londergan ◽  
Karin S. Åkerfeldt
Keyword(s):  
Raman Spectroscopy ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Peptide Sequence ◽  
Short Peptide ◽  
Dependent Behavior ◽  
Pka Determination ◽  
Key Functional Groups

Determining the pKa of key functional groups is critical to understanding the pH-dependent behavior of biological proteins and peptide-based biomaterials. Traditionally, 1H NMR spectroscopy has been used to determine the pKa of amino acids; however, for larger molecules and aggregating systems, this method can be practically impossible. Previous studies concluded that the C-D stretches in Raman are a useful alternative for determining the pKa of histidine residues. In this study, we report on the Raman application of the C2-D probe on histidine’s imidazole side chain to determining the pKa of histidine in a short peptide sequence. The pKa of the tripeptide was found via difference Raman spectroscopy to be 6.82, and this value was independently confirmed via 1H NMR spectroscopy on the same peptide. The C2-D probe was also compared to other Raman reporters of the protonation state of histidine and was determined to be more sensitive and reliable than other protonation-dependent signals. The C2-D Raman probe expands the tool box available to chemists interested in directly interrogating the pKa’s of histidine-containing peptide and protein systems.

Relative hydrogen index as a fast method for the simultaneous determination of physicochemical properties of petroleum fractions

Fuel ◽  
2017 ◽  
Vol 210 ◽  
pp. 41-48 ◽  
Author(s):  
Lúcio L. Barbosa ◽  
Luciana F. Montes ◽  
Flávio V.C. Kock ◽  
Vinícius G. Morgan ◽  
Andre Souza ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Simultaneous Determination ◽  
Hydrogen Index ◽  
Fast Method ◽  
Petroleum Fractions

Site-Specific pKa Determination of Selenocysteine Residues in Selenovasopressin by Using 77Se NMR Spectroscopy

2011 ◽  
Vol 50 (50) ◽  
pp. 11952-11955 ◽  
Author(s):  
Mehdi Mobli ◽  
David Morgenstern ◽  
Glenn F. King ◽  
Paul F. Alewood ◽  
Markus Muttenthaler
Keyword(s):  
Nmr Spectroscopy ◽  
Site Specific ◽  
Pka Determination ◽  
77Se Nmr Spectroscopy
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