Synthesis and Chiral Separation of Some 4-thioflavones

2021 ◽  
Author(s):  
Mohammed El Amin Zaid ◽  
Nasser Belboukhari ◽  
Khaled Sekkoum ◽  
Bousmaha Ibtissam ◽  
Hassan Y Aboul Enein
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Wittig Reaction ◽  
Stationary Phases ◽  
Enantiomeric Separation ◽  
Chiral Separations ◽  
Chiral Discrimination ◽  
Set Up

Abstract A thionation reaction was performed on some chiral flavanones using Lawesson’s reagent (LR) and leads to the formation of new chiral thiocarbonyl flavanes. LR in this thionation reaction with Hesperetin and Naringenin gives new flavan-4-thiones with yields ranged between 41 and 52%. Based on the Wittig reaction principle, LR is currently the most widely used reagent for this type of reaction. Enantiomeric separation by high-performance liquid chromatography methods was then set-up using three different polysaccharide-based chiral stationary phases (CSPs). Chiral separations were successfully accomplished with high resolution (1.22 ≤ Rs ≤ 5.23). The chiral discrimination mechanism(s) between the analytes under study, mobile phase, and the CSPs were discussed.

scholarly journals HPLC separation of panthenol enantiomers on different types of chiral stationary phases

2018 ◽  
Vol 11 (2) ◽  
pp. 114-119 ◽  
Author(s):  
Anna Lomenova ◽  
Katarína Hroboňová ◽  
Terézia Šolónyová
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Stationary Phases ◽  
Pharmaceutical Preparations ◽  
Chiral Stationary Phases ◽  
Biologically Active ◽  
Different Types

Abstract Panthenol is a biologically active compound closely related to vitamin B5 (pantothenic acid). This work deals with the separation of panthenol enantiomers using high performance liquid chromatography. Different types of chiral stationary phases (β-cyclodextrin, isopropyl carbamate cyclofructan 6, amylose tris(3,5-dimethylphenylcarbamate)) were tested in normal phase separation mode. Effect of mobile phase composition on the resolution and retention of enantiomers was studied. Two types of detectors, low-wavelength UV and polarimetric, were used. The optimal chromatographic system includes a chiral stationary phase based on amylose and a mobile phase of hexane/ethanol (60/40, v/v) where the resolution of enantiomers reached the value Rs = 2.49. Suitable chromatographic conditions were applied for the determination of panthenol enantiomers in samples of pharmaceutical preparations with the obtained recovery of more than 92 %. Linearity of the high performance liquid chromatography method with spectrophotometric detection was from 1.0 × 10−3 to 1.3 mg mL−1 (R2 = 0.998), with the limit of detection of 0.3 × 10−3 mg mL−1 for both enantiomers.

Direct Enantiomeric Separation of Flavanones by High Performance Liquid Chromatography using Various Chiral Stationary Phases

Planta Medica ◽  
1995 ◽  
Vol 61 (02) ◽  
pp. 171-176 ◽  
Author(s):  
Paola Ficarra ◽  
Rita Ficarra ◽  
Carlo Bertucci ◽  
Silvana Tommasini ◽  
Maria Calabrò ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Stationary Phases ◽  
Chiral Stationary Phases ◽  
Enantiomeric Separation

scholarly journals Direct Enantiomeric Separation and Determination of Hexythiazox Enantiomers in Environment and Vegetable by Reverse-Phase High-Performance Liquid Chromatography

2020 ◽  
Vol 17 (10) ◽  
pp. 3453
Author(s):  
Ping Zhang ◽  
Sheng Wang ◽  
Dongmei Shi ◽  
Yangyang Xu ◽  
Furong Yang ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
High Performance ◽  
Enantiomeric Separation ◽  
Reverse Phase ◽  
Column Temperature ◽  
Resolution Factor ◽  
Phase Temperature ◽  
Lower Temperature

In the present study, the direct enantiomeric separation of hexythiazox enantiomers on Lux cellulose-1, Lux cellulose-2, Lux cellulose-3, Lux cellulose-4, Lux amylose-1 and Chirapak IC chiral columns were carefully investigated by reverse-phase high-performance liquid chromatography (RP-HPLC). Acetonitrile/water and methanol/water were used as mobile phase at a flow rate of 0.8 mL·min−1. The effects of chiral stationary phase, temperature, thermodynamic parameters, mobile phase component and mobile phase ratio on hexythiazox enantiomers separation were fully evaluated. Hexythiazox enantiomers received a baseline separation on the Lux cellulose-3 column with a maximum resolution of Rs = 2.09 (methanol/water) and Rs = 2.74 (acetonitrile/water), respectively. Partial separations were achieved on other five chiral columns. Furthermore, Lux amylose-1 and Chirapak IC had no separation ability for hexythiazox enantiomers when methanol/water was used as mobile phase. Temperature study indicated that the capacity factor (k) and resolution factor (Rs) decreased with column temperature increasing from 10 °C to 40 °C. The enthalpy (ΔH) and entropy (ΔS) involved in hexythiazox separation were also calculated and demonstrated the lower temperature contributed to better separation resolution. Moreover, the residue analytical method for hexythiazox enantiomers in the environment (soil and water) and vegetable (cucumber, cabbage and tomato) were also established with reliable accuracy and precision under reverse-phase HPLC condition. Such results provided a baseline separation method for hexythiazox enantiomers under reverse-phase conditions and contributed to an environmental and health risk assessment of hexythiazox at enantiomer level.

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