scholarly journals Isolation and structural elucidation of the degradation products of pregnanediol disulfate obtained by hot acid hydrolysis (Clinical analysis on steroids. XXI).

1982 ◽  
Vol 30 (7) ◽  
pp. 2474-2486 ◽  
Author(s):  
ITSUO YOSHIZAWA ◽  
RYOKO OHUCHI ◽  
KYOKO NAGATA ◽  
SHINJI ITOH ◽  
NORIO KAWAHARA
Keyword(s):  
Acid Hydrolysis ◽  
Degradation Products ◽  
Clinical Analysis ◽  
Structural Elucidation

Structural Elucidation of Unknown Oxidative Degradation Products of Mycophenolate Mofetil Using LC-MSn

2016 ◽  
Vol 79 (13-14) ◽  
pp. 919-926 ◽  
Author(s):  
Ana Protić ◽  
Marina Radišić ◽  
Jelena Golubović ◽  
Biljana Otašević ◽  
Mira Zečević ◽  
...  
Keyword(s):  
Mycophenolate Mofetil ◽  
Degradation Products ◽  
Oxidative Degradation ◽  
Structural Elucidation

Investigation of acid hydrolysis for carbohydrate analysis in kraft black liquor

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Silvia Maitz ◽  
Marlene Kienberger
Keyword(s):  
Acid Hydrolysis ◽  
High Performance ◽  
Degradation Products ◽  
Black Liquor ◽  
Amperometric Detection ◽  
Kraft Process ◽  
Kraft Black Liquor ◽  
Carbohydrate Degradation ◽  
Reliable Detection ◽  
Hydrolysis Of

Abstract Black liquor (BL) from the kraft process is considered a promising feedstock for several biorefinery scenarios. Besides lignin and carboxylic acids, this liquor also contains hemicelluloses and their degradation products. A simple and reliable detection of those is of importance for further processing of the liquor. The present paper presents a thorough investigation of quantitative analysis of carbohydrates, by performing acid hydrolysis experiments with a concentrated BL sample of 44% total dry solids. The hydrolysates were then analysed for the four monosaccharides arabinose, xylose, galactose and glucose, by high performance ion chromatography (HPIC) with pulsed amperometric detection. The amount of sulphuric acid needed for complete hydrolysis of the carbohydrates was determined in the range of 3.5–5 mol kg−1 of BL. A lower acid concentration led to insufficient liberation of galactose and glucose, while higher acid concentrations led to degradation of arabinose and xylose. The carbohydrate degradation was also investigated over time for different dilutions and hydrolysis temperatures. These experiments confirmed that the hexoses require considerably harsher conditions for complete liberation compared to xylose and arabinose. The use of internal recovery standards (RSs) was tested; the highest recoveries were obtained by direct spiking of the samples with the RS prior to hydrolysis.

Characterization of stress degradation products of blonanserin by UPLC-QTOF-tandem mass spectrometry

RSC Advances ◽  
2015 ◽  
Vol 5 (85) ◽  
pp. 69273-69288 ◽  
Author(s):  
Pradipbhai D. Kalariya ◽  
Prinesh N. Patel ◽  
Mahesh Sharma ◽  
Prabha Garg ◽  
R. Srinivas ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Tandem Mass Spectrometry ◽  
Degradation Products ◽  
Structural Elucidation ◽  
Forced Degradation ◽  
Tandem Mass ◽  
Degradation Study ◽  
Stress Degradation

Forced degradation study of blonanserin and structural elucidation of its degradation products was performed using high resolution tandem mass spectrometry.

scholarly journals A Novel Acylated Flavone Glycoside from Andrographis nallamalayana

2007 ◽  
Vol 2 (5) ◽  
pp. 1934578X0700200
Author(s):  
Nimmanapalli P. Reddy ◽  
Bandi A.K. Reddy ◽  
Duvvuru Gunasekar ◽  
Alain Blond ◽  
Bernard Bodo ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Acid Hydrolysis ◽  
Structural Elucidation ◽  
Flavone Glycoside ◽  
Whole Plant ◽  
Nmr Techniques ◽  
Labdane Diterpenoids

A new acylated flavone glycoside, skullcapflavone I 2′- O-β-D-(6″- E-cinnamoyl) glucopyranoside (1), together with two known flavones, 5,2′-dihydroxy-7-methoxyflavone (2) and 5,2′,6′-trihydroxy-7-methoxyflavone-2′- O-β-D-glucopyranoside (3), and two known labdane diterpenoids, 14-deoxy-11,12-didehydroandrographolide (4) and andrographolide (5) were isolated from the whole plant of Andrographis nallamalayana. Structural elucidation of the new compound, as well as of the known compounds was achieved by various NMR techniques including 1H-1H COSY, HSQC, HMBC and ROESY experiments, ESITOF mass spectrometry, acid hydrolysis and saponification studies.

scholarly journals Implementation of Auto-Hydrolysis Process for the Recovery of Antioxidants and Cellulose from Wheat Straw

2020 ◽  
Vol 10 (17) ◽  
pp. 6112 ◽  
Author(s):  
Andrea Bassani ◽  
Cecilia Fiorentini ◽  
Vellingiri Vadivel ◽  
Alessandro Moncalvo ◽  
Giorgia Spigno
Keyword(s):  
Acid Hydrolysis ◽  
Wheat Straw ◽  
Degradation Products ◽  
Cost Effective ◽  
Point Of View ◽  
Full Potential ◽  
Cellulose Yield ◽  
Whole Process ◽  
Hydrolysis Process ◽  
Environmentally Friendly Process

Wheat straw is an easily affordable, cost-effective and natural source of antioxidants and cellulose, but its full potential is not yet utilized. In the present investigation, an auto-hydrolytic process was applied to recover both antioxidant phenolic compounds and cellulose from wheat straw. Two three-step acid/alkaline fractionation processes were applied differing for the first step: a conventional mild acid hydrolysis or an auto-hydrolysis. The liquors from the first step were analyzed for the recovery of antioxidants, while the final residues from the whole process were analyzed for cellulose yield and purity. The auto-hydrolysis process led to a higher yield in antioxidants but also in sugars (glucose and xylose) and sugar degradation products (5-HMF, 5-MF, furfural) than the acid hydrolysis process. The overall cellulose recovery (about 45% g/100 gcellulose wheat straw dm) and purity was comparable in the two processes; therefore, the auto-hydrolysis-based process could be recommended as a potentially more environmentally friendly process to recover antioxidants and cellulose from wheat straw for different applications. Finally, a first study on the optimization of hydrolysis step was provided from the point of view of improving the cellulose yield, monitoring the sugars release during both the acid hydrolysis and the auto-hydrolysis process.

Mechanism driven structural elucidation of forced degradation products from hydrocortisone in solution

2016 ◽  
Vol 128 ◽  
pp. 333-341 ◽  
Author(s):  
Fa Zhang ◽  
Jay Zhou ◽  
Yiqun Shi ◽  
Panagiotis Tavlarakis ◽  
Kenneth Karaisz
Keyword(s):  
Degradation Products ◽  
Structural Elucidation ◽  
Forced Degradation
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