نتایج جستجو برای: o methylated free trimethyl chitosan
تعداد نتایج: 1077417 فیلتر نتایج به سال:
Per-O-methylated cyclodextrins containing a single 2-O-(2-acetate), 2-O-(3-propanoate) or a 6-carboxylate were investigated for glycosidase activity on p-nitrophenyl glycosides. The former two compounds displayed enzyme catalysis giving rate accelerations of 500-1000, while the latter compound gave marginal catalysis. These results show that per-O-methylated cyclodextrins direct substrate bindi...
Based on chelation effect between iron ions and amino groups of chitosan, in situ mineralization of magnetite nanoparticles in chitosan hydrogel under ambient conditions was proposed. The chelation effect between iron ions and amino groups in CS-Fe complex, which led to that chitosan hydrogel exerted a crucial control on the magnetite mineralization, was proved by X-ray photoelectron spectrum. ...
The Mediterranean Ononis species, O. fruticosa, O. natrix subsp. ramosissima and O. tridentata, have been analyzed for their exudate flavonoids. More than 20 flavonoid aglycones were identified, some of which are rather rare natural compounds. One of them, namely hypolaetin-8,3',4'-trimethyl ether, had been found only once before. The results are presented in a table along with literature data,...
Chitosan the second most abundant polysaccharide is biodegradable, biocompatible, and nontoxic. These properties makes chitosan widely applicable in the pharmaceutical and biomedical fields for controlled release of drugs for wound management and space filling implants etc. In the present study fungal chitosan is isolated form Cunninghamella elegans, characterized by FT-IR spectroscopy by confi...
The title compound {systematic name: (1R,4S,4aS,7R,8aR)-4-bromo-7-[(1S,3R)-3-bromo-1,2,2-trimethyl-cyclo-pent-yl]-1,4a-dimethyl-deca-hydro-naphthalene-1,7,8a-triol}, C(20)H(34)Br(2)O(3), is a neoirieane-type bromo-diterpenoid isolated from Laurencia yonaguniensis Masuda et Abe, species inedita. The absolute stereochemistry was established as (1S,4R,5R,7R,10S,11S,14R). The structure displays int...
Abstract Culture supernatants of Basfia succiniciproducens derived from the industrial production succinic acid exhibit an intense nutty, root vegetable‐like, buttery and sourish smell. By means headspace‐gas chromatography‐mass spectrometry‐olfactometry (HS‐GC‐MS‐O), 14 odour‐active compounds were perceived identified using two GC‐columns different polarity comparison retention indices mass sp...
aacel9a [β-1,4-endoglucanase, (e.c:3.2.1.4)], was immobilized onto glutaraldehyde activated chitosan macrosphere by covalent attachment. the properties of the immobilized aacel9a were investigated by determining the optimum ph and optimum temperature for activity, thermal stability, and kinetic parameters. the immobilization process shifted the enzyme’s optimum temperature from 65 °c for the fr...
The control of size and size distribution of microspheres is necessary for obtaining repeatable controlled release behavior. The chitosan microspheres were prepared by a membrane emulsification technique in this study. Chitosan was dissolved in 1 wt.% aqueous acetic acid containing 0.9 wt.% sodium chloride, which was used as a water phase. A mixture of liquid paraffin and petroleum ether 7:5 (v...
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