Solvent Systems for Crystallization and Polymorph Selection

Author(s):  
JONATHAN M. MILLER ◽  
NAÍR RODRÍGUEZ-HORNEDO ◽  
ANTHONY C. BLACKBURN ◽  
DAINIUS MACIKENAS ◽  
BENJAMIN M. COLLMAN
1969 ◽  
Vol 67 (1_3) ◽  
pp. 168-168
Author(s):  
H. G. Hertz

1963 ◽  
Vol 44 (1) ◽  
pp. 101-106 ◽  
Author(s):  
Wilhelm Dirscherl ◽  
Helmut Thomas

ABSTRACT Perfusion of rat liver with vanillic acid yielded only one metabolite. In paper chromatography with three different solvent systems, the substance showed the same RF-values as vanillyolglycine (3-methoxy-4-hydroxyhippuric acid) and in mixed chromatograms there was only one single spot. After separation by column chromatography, the UV- and IRspectra of the reaction product were identical with those of 3-methoxy4-hydroxy-hippuric acid. During the perfusion experiment, the kinetics of the conjugation were investigated.


2014 ◽  
Vol 21 (1) ◽  
pp. 11-15
Author(s):  
Daiva Kazlauskienė ◽  
Guoda Kiliuvienė ◽  
Palma Nenortienė ◽  
Giedrė Kasparavičienė ◽  
Ieva Matukaitytė

By conducting the toxicological analysis it is meaningful to determine the analytical system that could identify simultaneously several medicinal preparations quickly and precisely. The purpose of this work was to create and validate the method of thin-layer chromatography that would be suitable to separate the components of antidepressant mixture (amitriptyline hydrochloride, paroxetine hydrochloride, sertraline hydrochloride, fluvoxamine maleate and buspirone hydrochloride) and to identify them. The system was validated with regard to the sensitivity, repetition of data, resistance and particularity. The solvent systems with potential of high separation of components in their mixture were created: acetonitrile, methanol, ammonia solution 25 percent (85:10:5); acetonitrile, methanol, ammonia solution 25 percent (75:20:5); dichlormethane, 1,4-dioxane, ammonia solution 25 percent (50:45:5); dichlormethane, 1,4-dioxane, ammonia solution 25 percent (42:55:3); trichlormethane, 1,4-dioxane, ammonia solution 25 percent (25:70:5); trichlormethane, 1,4-dioxane, ammonia solution 25 percent (60:36:4). One of the most suitable solvent systems for separation of the analyzed mixture (sertraline, amitriptyline, paroxetine, buspirone, fluvoxamine) was determined – acetonitrile, methanol, ammonia solution 25 percent (85:10:5). When this solvent system was used, the average Rf values of the analyzed compounds differed the most. Validation was conducted – the relative standard deviation (RSD, percent) of the average Rf value of the analyzed compounds varied from 0,6 to 1,8 percent and did not exceed the permissible error of 5 percent. The sensitivity of methodology was determined by assessing the intensity of the mixture’s spots on the chromatographic plate. The detection limit of buspirone was 0,0012 µg; sertraline – 0,0008 µg; amitriptyline – 0,0004 µg; fluvoxamine – 0,0004 µg; paroxetine – 0,0008 µg. The resistance of results to the changed conditions – it was determined that when the amounts of the solvents acetonitrile and methanol were increased or decreased to two milliliters, the average Rf values of the analyzed compounds did not change statistically significantly


2018 ◽  
Vol 69 (10) ◽  
pp. 2682-2692 ◽  
Author(s):  
Candice Popescu (Popiniuc) ◽  
Carmen Popescu ◽  
Stefan Manea ◽  
Valentin Vladut ◽  
Iulian Voicea ◽  
...  

In this paper, a study on the influence of extraction solvent on the active principles content of purslane - Portulaca oleracea extracts was performed. For the study were used both fresh and dried plants, chopped by plant chopping machine. The following extracts were obtained and analysed in the solvent systems mentioned below: (fresh) purslane extract in Ethanol 30%, (dry) purslane extract in Ethanol 30%; (fresh) purslane extract in EtOH 70%, (dry) purslane extract in EtOH 70%; (fresh) purslane extract in propylene glycol 20%, (dry) purslane extract in propylene glycol 20%; (fresh) purslane extract in PG 100%, (dry) purslane extract in PG 100%; (fresh) purslane extract in glycerine 20%, (dry) purslane extract in glycerine 20%; (fresh) purslane extract in R glycerine, (dry) purslane extract in R glycerine; purslane hydro-alcoholic glycerine extract. The results obtained in the study performed on purslane extracts in different solvents show that the capitalization of purslane can become very profitable and with beneficial effects on economy in our country, both in terms of food and as medicinal plant.


Author(s):  
Dr. Akash S Changole ◽  
Mandip Goyal ◽  
Harish CR

Background: Quality control and the standardization of herbal medicines involve steps like standard source and quality of raw materials, good manufacturing practices and adequate analytical screening. These practices play a vital role in guaranting the quality and stability of herbal preparations. Chandrashakaladi Vataka is an Ayurvedic herbal formulation mentioned to be beneficial in Kushtha. Till date no published data is available on its analytical profile. Aim: To develop the Pharmacognostical and Phyto-chemical profile of Chandrashakaladi Vataka. Material and Methods: Chandrashakaladi Vataka was prepared as per classical method and analytical findings were recorded. Samples were subjected to organoleptic analysis, physico-chemical analysis and HPTLC examination by optimizing the solvent systems. Results and Conclusions: Pharmacognostical profile of Chandrashakaladi Vataka was established. Loss on drying, Ash value, Acid insoluble extract, Methanol soluble extract, Chandrashakaladi Vataka was found within prescribed limits. HPTLC profile of Chandrashakaladi Vataka revealed 12 spots at 254 nm and 13 spots at 366 nm.


2021 ◽  
Author(s):  
Amir Al Ghatta ◽  
James D. E. T. Wilton-Ely ◽  
Jason P. Hallett

Process simulations allow the evaluation of the emissions and selling price for the production of the key monomer FDCA based on different feedstocks and solvent systems, alongside considerations of safety and current process development.


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 484
Author(s):  
Aprajita Tiwari Pandey ◽  
Ishan Pandey ◽  
Anurag Kanase ◽  
Amita Verma ◽  
Beatriz Garcia-Canibano ◽  
...  

Mushrooms produce a variety of bioactive compounds that are known to have anti-pathogenic properties with safer and effective therapeutic effects in human disease prognosis. The antibacterial activity of ethanol and methanol extracts of Pleurotus opuntiae were checked against pathogenic microorganisms viz. Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis NCIM 2300, Proteus vulgaris NCIM 5266, Serratia marcescens NCIM 2078, Shigella flexeneri NCIM 5265, Moraxella sp. NCIM 2795, Staphylococcus aureus ATCC 25923 by agar well diffusion method at different concentrations of the extracts. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the extracts was determined by INT (Iodonitrotetrazolium chloride) colorimetric assay. Extracts were standardized by thin layer chromatography (TLC) in different solvent systems. The Retention factors (Rf) of different compounds were calculated by high performance TLC (HPTLC) fingerprinting at UV 254, 366, and 540 nm before and after derivatization. The ethanol and methanol extracts of P. opuntiae showed bactericidal activity against all the test pathogens at MIC values of 15.6 to 52.08 mg/mL and 20.81 to 52.08 mg/mL respectively. Whereas the MBC values for ethanol and methanol extract of P. opuntiae against all pathogens were recorded as 26.03 to 62.5 mg/mL and 125 mg/mL respectively. Preliminary mycochemical screening of both the extracts revealed high contents of bioactive compounds. Amongst all the solvent systems used in TLC, the best result was given by chloroform + hexane (8:2) which eluted out 5 different compounds (spots). HPTLC results revealed spots with different Rf values for all the 24 compounds present. Thus, it can be inferred from the present investigation that the mycoconstituents could be an alternative medication regimen and could play a role in new drug discoveries against different infections. Further, the antimicrobial components of these mushrooms can be transformed to bioengineered antimicrobial coatings for surfaces, drug and other hybrid systems for public health implications in combating persistent infections.


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