نتایج جستجو برای: flash chromatography
تعداد نتایج: 124038 فیلتر نتایج به سال:
Optical resolution of racemic 5-oxo-1-phenyl-pyrazolidine-3-carboxylic acid 2 with L-amino acid methyl ester via the diastereomers formation was investigated. Treatment of racemic 5-oxo-1-phenylpyrazolidine-3-carboxylic acid 2 with L-valine methyl ester gave diastereomers with a total yield of 86%. The diastereomeric dipeptides can be easily separated by flash column chromatography. Acidic clea...
A procedure is described for the purification of cytochrome c peroxidase from Pseudomonas aeruginosa involving extraction by sonication, followed by acid precipitation and chromatography on only two types of gel. The final preparation had a purity ratio A407/A280 of 4.2, and was found to be essentially pure by isoelectric focusing. The enzyme was shown to be unstable during degassing under vacu...
The title compound, C(36)H(58)O(8), was prepared from 20(S)-protopanaxatriol, which was degraded from Panax quinquefolium saponin with sodium in glycerine, extracted and seperated by flash chromatography. Three six-membered rings are in chair conformations, the five-membered ring is in an envelope form and the tetra-hydro-furan ring has a conformation inter-mediate between half-chair and envelo...
A novel procedure for the synthesis of isoxazolin-5-one glycosides starting from unprotected carbohydrates is described. The substrate scope of the one-pot synthetic protocol was explored using D-configured glucose, xylose, maltose, fructose, ribose and 2-deoxyribose. Naturally occurring 2-(β-D-glucopyranosyl)-3-isoxazolin-5-one and four novel isoxazolin-5-one glycosides derived from xylose, ma...
In this paper, we formulate the problem of natural image matting as one of solving Poisson equations with the matte gradient field. Our approach, which we call Poisson matting, has the following advantages. First, the matte is directly reconstructed from a continuous matte gradient field by solving Poisson equations using boundary information from a user-supplied trimap. Second, by interactivel...
Fruits and vegetables are an essential part of a healthy diet, providing humans with vitamins, phytonutrients, minerals. They significantly vulnerable, however, to post-harvest diseases caused by numerous fungal bacterial pathogens. These pathogens can cause significant quantitative qualitative losses from harvest consumption during the handling storage processes. Chemical fungicides commonly u...
Different symptoms in Climacteric period, includes hot flash. Hormone replacement therapy (HRT) is common therapy for relief of menopausal symptoms but has possible contraindications and side effects. Recently Piascledine (combination of Avocado oil with Soybean oil) showed effects in reducing hot flash severity. Present study designed to compare the effects of HRT with Piascledine in treatment...
Condensed tannins and polymeric pigments are essential red wine components that contribute to color stability, taste, mouthfeel. Phenolic polymers in consist of flavan-3-ol monomers anthocyanins cause the perception astringency. Due chemical heterogeneity proanthocyanidin polymers, analytical tools determine polymers’ structural features limited. Incorporation increases complexity even more mak...
Different symptoms in Climacteric period, includes hot flash. Hormone replacement therapy (HRT) is common therapy for relief of menopausal symptoms but has possible contraindications and side effects. Recently Piascledine (combination of Avocado oil with Soybean oil) showed effects in reducing hot flash severity. Present study designed to compare the effects of HRT with Piascledine in treatment...
Herein we describe an efficient and rapid access to 3′-deoxy-3′-(4-substituted-1,2,3-triazol-1-yl)-thymidine derivatives using 1,3-dipolar cycloaddition reaction catalyzed by copper(I). Innovative conditions allow us generate target compounds in a one-pot mixing 3′-azido-3′-deoxythymidine, alkyne, copper sulfate pentahydrate, sodium ascorbate tris(benzyltriazolylmethyl)amine water:tert-butanol ...
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