نتایج جستجو برای: epoxy compounds
تعداد نتایج: 239236 فیلتر نتایج به سال:
Eight new withanolides were isolated from the aerial parts of Vassobia lorentzii and characterized by spectroscopic methods and with the aid of molecular modeling. The compounds were identified as (17S,20R,22R)-5beta,6beta:18,20-diepoxy-18-hydro xy-1-oxowitha-2,5, 24-trienolide (1); (17S,20R,22R)-18,20-epoxy-4beta, 18-dihydroxy-1-oxowitha-2,5,24-trienolide (2); (17S,18R,20R, 22R)-4beta-hydroxy-...
migration of compounds from packaging materials is one of the most important aspects of food safety. epoxy resins have been in inner coatings of food cans since the 1960s. these resins can be produced from bisphenol-a diglycidyl ether (badge) that is also utilized as a starter. migration of potentially toxic compounds in epoxy resins used for commercial cans is a very important food safety issu...
An overview of the synthesis and applications of chiral 2,3-epoxy alcohols containing unsaturated chains is presented. One of the fundamental synthetic routes to these compounds is Sharpless asymmetric epoxidation, which is reliable, highly chemoselective and enables easy prediction of the product enantioselectivity. Thus, unsaturated epoxy alcohols are readily obtained by selective oxidation o...
Various situations are explored in which the nickel(0)-catalyzed enyne-epoxide reductive coupling was utilized to access key intermediates towards the total synthesis of (-)-cyatha-3,12-diene (1). Enantioenriched 3,5-dien-1-ols with a variety of functionality were obtained in a straightforward manner from easily accessible 1,3-enynes and terminal epoxides.
A strain of the fungus Fusarium equiseti isolated from soybean cyst nematode secretes nematode-antagonistic compounds. Bioassay-guided fractionation of an extract of the culture broth was undertaken to identify the compounds. Fractions were assayed for activity against a root-knot nematode (Meloidogyne incognita), a plant pathogen that attacks the roots of numerous plant species. Two trichothec...
1. Oxidation of vitamin A acetate with monoperphthalic acid gave 5,6-monoepoxyvitamin A acetate, C(22)H(32)O(3), obtained as pale-yellow crystals, m.p. 65-66 degrees . 2. Saponification of 5,6-monoepoxyvitamin A acetate yielded 5,6-monoepoxyvitamin A alcohol, which was readily oxidized with manganese dioxide to 5,6-monoepoxyvitamin A aldehyde, obtained as yellow crystals, m.p. 101-102 degrees ....
in this research, mesoporous silica was applied as the host of corrosion inhibitor (molybdate). the loaded mesoporous silica was dispersed in an epoxy matrix. the composite was then coated on the mild steel plate. results showed that the corrosion resistance of the scratched epoxy/mesoporous silica loaded by molybdate was better than the one without molybdate or neat epoxy. on the other hand, e...
A total of two new (1, 2) and four known (3-6) withanolides were isolated from the whole plant of Withania somnifera. Their structures were elucidated on the basis of spectroscopic techniques and were characterized as 6alpha,7alpha-epoxy-3beta,5alpha,20beta-trihydroxy-1-oxowitha-24-enolide (1), 5beta,6beta-epoxy-4beta,17alpha,27-trihydroxy-1-oxowitha-2,24-dienolide (2), withaferin-A (3), 2,3-di...
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