Detection and substitution-pattern determination of guanidines

1976 ◽  
Vol 32 (3) ◽  
pp. 284-285
Author(s):  
Renée A. Corral ◽  
O. O. Orazi ◽  
María E. González
Keyword(s):  
Substitution Pattern ◽  
Pattern Determination

scholarly journals Liquid Phase and Microwave-Assisted Extractions for Multicomponent Phenolic Pattern Determination of Five Romanian Galium Species Coupled with Bioassays

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1226 ◽  
Author(s):  
Andrei Mocan ◽  
Alina Diuzheva ◽  
Sabin Bădărău ◽  
Cadmiel Moldovan ◽  
Vasil Andruch ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Iridoid Glycosides ◽  
Deep Eutectic Solvent ◽  
Inhibitory Effect ◽  
Total Phenolic ◽  
Extraction Solvent ◽  
Microwave Assisted ◽  
Pattern Determination ◽  
Natural Deep Eutectic Solvent

Background: Galium is a plant rich in iridoid glycosides, flavonoids, anthraquinones, and small amounts of essential oils and vitamin C. Recent works showed the antibacterial, antifungal, antiparasitic, and antioxidant activity of this plant genus. Methods: For the determination of the multicomponent phenolic pattern, liquid phase microextraction procedures were applied, combined with HPLC-PDA instrument configuration in five Galium species aerial parts (G. verum, G. album, G. rivale, G. pseudoaristatum, and G. purpureum). Dispersive Liquid–Liquid MicroExtraction (DLLME) with NaCl and NAtural Deep Eutectic Solvent (NADES) medium and Ultrasound-Assisted (UA)-DLLME with β-cyclodextrin medium were optimized. Results: The optimal DLLME conditions were found to be: 10 mg of the sample, 10% NaCl, 15% NADES or 1% β-cyclodextrin as extraction solvent—400 μL of ethyl acetate as dispersive solvent—300 μL of ethanol, vortex time—30 s, extraction time—1 min, centrifugation at 12000× g for 5 min. Conclusions: These results were compared with microwave-assisted extraction procedures. G. purpureum and G. verum extracts showed the highest total phenolic and flavonoid content, respectively. The most potent extract in terms of antioxidant capacity was obtained from G. purpureum, whereas the extract obtained from G. album exhibited the strongest inhibitory effect against tyrosinase.

Determination of substituent distribution of viscoses by GPC

Holzforschung ◽  
2006 ◽  
Vol 60 (5) ◽  
pp. 467-473 ◽  
Author(s):  
Axel Rußler ◽  
Antje Potthast ◽  
Thomas Rosenau ◽  
Thomas Lange ◽  
Bodo Saake ◽  
...  
Keyword(s):  
Enzymatic Degradation ◽  
Laser Light ◽  
Gel Permeation Chromatography ◽  
Narrow Molecular Weight Distribution ◽  
Substitution Pattern ◽  
Degradation Pattern ◽  
Long Time ◽  
Ultrasonic Degradation ◽  
Insight Into

Abstract Based on previous investigations on the substitution pattern of stabilized and fresh viscose, different viscoses were analyzed by gel permeation chromatography (GPC) with multiple-angle laser light scattering, refractive index (RI), and UV detection. Viscoses derivatized with N-methyl-N-phenyl-iodoacetanilide are stable over a long time and largely improve handling for analytical purposes. In addition, the derivatized xanthogenate groups exhibit UV absorbance that can be used to detect their distribution along the polymer molecule, once the polymer is dissolved. UV assay indicated that in technical viscoses the distribution of substituents is uniform. Enzymatic degradation with endoglucanases was followed by analysis of the degradation pattern by GPC. Even though the degree of substitution (DS) of xanthogenate groups ranged from γ=0.4 to 0.6, endoglucanases were able to slightly degrade the viscose. Ultrasonic degradation resulted in a narrow molecular weight distribution (MWD), notably without cleavage of substituents, and was also used to improve the solubility of the stabilized viscoses for further analysis. The techniques applied provide more insight into the xanthogenate distribution along the MWD. Remarkable differences in the degradation behavior of both viscose samples were observed.

scholarly journals Application of INDOR and NOE techniques to determination of the substitution pattern on an aromatic ring of erythrinan alkaloids.

1978 ◽  
Vol 26 (2) ◽  
pp. 563-570 ◽  
Author(s):  
MOTOHARU JU-ICHI ◽  
YOSHIKO ANDO ◽  
AKIKO SATOH ◽  
JUNICHI KUNITOMO ◽  
TETSURO SHINGU ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Substitution Pattern

scholarly journals Binding Pattern Determination Of Class of Antifungal Drugs

2010 ◽  
Author(s):  
Arpit Tandon ◽  
Arpit Tandon ◽  
A Naqvi ◽  
Nitin Chitranshi ◽  
Siddharth Sinha
Keyword(s):  
Antifungal Drugs ◽  
Binding Pattern ◽  
Pattern Determination
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