• Title/Summary/Keyword: Alcoholysis

Search Result 14, Processing Time 0.019 seconds

A Study on Alkyl Glucoside Synthesis by Amphiphilic Phase Enzyme Reaction (양친매상 효소반응에 의한 알킬글루코시드의 합성연구)

  • 허주형;임교빈김해성
    • KSBB Journal
    • /
    • v.11 no.5
    • /
    • pp.511-517
    • /
    • 1996
  • An amphiphilic phase enzyme reaction was used to synthesize alkyl glucosides from glucose and alkyl alcohol with immobilized ${\beta}$-glucosidase using four glycol ether cosolvents(monoglyme, diglyme, 2-methoxyethanol, and 1,4-dioxane). Monoglyme was shown to be the best cosolvent for the amphiphilic phase medium composed of water/cosolvent/alkyl alcohol admixture. To obtain high yield of alkyl glucoside by amphiphilic phase enzyme reaction, hydrophilicity-hydrophobicity of amphiphilic media and enzyme microenvironment was optimized from the viewpoints of substrate solubility, enzyme activity, water activity, and dynamic equilibrium between glucose alcoholysis and glucoside hydrolysis. Under optimum reaction conditions, the highest concentrations of hexyl, octyl, decyl, and dodecyl glucosides were 18.2, 9.68, 7.27, and 6.03g/L, respectively.

  • PDF

Organotitanium Chemistry II. Solvolytic Reaction of Dichlorodiacetatotitanium (IV) with Various Alcohols (유기-티탄화학 (제2보). Dichlorodiacetatotitanium (IV) 여러 알콜과의 가용매반응)

  • Hoo Sung Lee;Young Sun Un;Sohn Youn Soo;Choi Q. Won
    • Journal of the Korean Chemical Society
    • /
    • v.17 no.3
    • /
    • pp.174-181
    • /
    • 1973
  • Dichlorodiacetatotitanium(IV) dissolves in alcohols with chemical reaction. Such solvolytic reaction of $TiCl_2(OAc)_2$with various alcohols has been studied by means of solution NMR spectroscopy and chemical analysis of the isolated products. The reaction of $TiCl_2(OAc)_2$ with primary alcohols has shown to be a quantitative two-step ligand substitution process as shown in the following: $TiCl_2(OAc)_2+ROH{\to}TiCl_2(OAc)_2(OR)+AcOH$ $TiCl_2(OAc)_2(OR)+ROH{\to}TiCl_2(OAc)_2+AcOH$The molecular form initially soluble in organic solvents has been found to be the monosubstituted species $TiCl_2(OAc)(OR)$. Alcoholysis with t-butyl alcohol has shown remarkable differences. When the mole ratio of t-butyl alcohol to $TiCl_2(OAc)_2$ is less than 1/2, the following reaction is dominant. $TiCl_2(OAc)_2+t-ButOH{\to}TiCl_2(OAc)_2+t-ButCl$However, at higher mole ratio another substitution process resembling the first step reaction with primary alcohols is competitively accompanied. The reaction with t-butyl alcohol also differs from that with primary alcohols in that only one either of the two chloro-or acetato-ligands in $TiCl_2(OAc)_2$ is subjected to substitution.

  • PDF

Purification and Biological Activity of Ecdysterone from Korean Achyranthes radix (韓國産 牛膝의 Ecdysterone 抽出과 그 生理活性에 관한 硏究)

  • Kim, Jeong-Il;Lee, Jae-Yong;Kim, Chun-Su;Park, Kwang-E.
    • Journal of Sericultural and Entomological Science
    • /
    • v.25 no.1
    • /
    • pp.1-20
    • /
    • 1983
  • It has been known that the insect molting hormone and its analogues exist also in plant kingdom and their concentration has been found to be about 0.1~2.0% of dry matter, which is equivalent to $10^3{\sim}10^5$ times of those in insects. This study was carried out; 1) to isolate the phytoecdysones from Korean Achyranthes radix and characterize their physico-chemical properties. 2) to investigate the biological activity of this phytoecdysone on Bombyx mori larvae. The resuls were summarized as follows; 1. The extraction method of phytoecdysones was optimized by three consecutive reflux for 1hr using 200g of dried and milled radix per 1l methanol. 2. The purification from the crude extract was made by a series of steps such as precipitation of gum-type polymer with n-Butyl acetate, adsorption on technical grade silica and chromatography with neutral alumina. The conditions of each step were optimized and the resulting crude crystal was about 500mg per kg dry radix. 3. The crude crystal from the cultivated Achyranthes(Achyranthes japonia) contained ecdysterone (20-hydroxyecdysone) and inokosterone in the proportion of one to one. In order to separate these, a series of processes such as acetylation, separation by alumina column chromatography deacetylation by alcoholysis, deionization and crystallization were introduced and optimized 125mg of ecdysterone and 18mg of inokosterone per kg dry radix were thus obtained. 4. The wild Achyranthes (Achyranthes obtusifolia) radix was found to contain the ecdysterone only. A 285mg of ecdysterone was crystallized per kg dry radix. 5. Isolated ecdysterone, inodosterone and acetylated compounds were characterized by IR., UV., NMR spectroscopy, mp, TLC and densitometry. 6. Ligation experiment was undertaken to confirm the biological activity of the purified ecdysterone; the ecdysterone could induce larval-pupal metamorphosis in the ligated abdomen of 4th instar larvae injecting 0.5~1.0${\mu}g$. 7. By ecdysterone feeding experiment using artificial diet, it was elucidated that the critical time of feeding would be the first half of each instar resulting in increased weight of silk layer. 8. The ecdysterone was fed to 5th instar silkworm at the level of 1, 2, 3, 5ppm of dry feed of artificial diet containing 5% mulberry leaves for 72hrs. At 2ppm of the concentration. body weight and silk layer weight were arrived at maximum. But at higher concentrations body weight and silk layer weight decreased than the control group. At 2ppm of the concentration, body weight was increased by 12.5%. 9. Feeding 2ppm of ecdysterone at the later half of 5th instar, the duration of larvae was shortened.

  • PDF

Development of High-Functional Hyaluronic Acid/Salmon Extract Formulation Using Gamma-Ray (감마선을 이용한 고기능성 히알루론산/연어추출물 제형개발)

  • Kweon, Dong-Keon;Shim, Jae-Goo;Ha, Man
    • Journal of the Korean Society of Radiology
    • /
    • v.12 no.1
    • /
    • pp.9-16
    • /
    • 2018
  • Hangover after drinking is different from person to person symptoms and degree, but usually thirst, fatigue, headache, general boredom, gastrointestinal disorder, vomiting, diarrhea, deficiency of vitamin appears. This hanging phenomenon is caused by the action of precursors such as ethyl acetate and acetaldehyde, which are the by products of fermentation contained in alcohol and alcohol accumulated in hepatocytes and body. In order to solve the hangover phenomenon, the same Origin as polysaccharide Polydeoxyribonucleotide, which is a nucleic acid-sugar-phosphate complex, which is a semen or testicular extract in salmon extract, and a water soluble salmon extract powder having the same structure and lower price than Polydeoxyribonucleotide And D-Glucuronic acid and N-Acetyl glucosamine. It has excellent biocompatibility, viscoelasticity and moisturizing power. It has effect on reduction of body water loss and skin moisture content in hangover phenomenon. It is antioxidant and skin moisturizing effect Hyaluronic acid was irradiated with gamma rays, and the composition was prepared by using the salmon extract powder and the main raw material. The ethanol degradation, the acetaldehyde reduction amount, the blood acetaldehyde concentration and the acetic acid concentration were measured to evaluate the alcoholysis effect, Skin moisture evaporation rate To examine the evaluation unit water content of the skin was improved determine whether the antioxidant and provide skin moisturizing effect. The addition of ethanol extracts of salmon extracts showed a decrease of 5 to 7 times compared with no addition, and a decrease of 3 to 5 times of acetaldehyde. In addition, the change of acetaldehyde concentration and acetic acid concentration in blood showed a rapid decrease compared to the no - added control group. In addition, when the raw material of hyaluronic acid was used, skin moisture content was high and skin moisture evaporation amount was decreased. Therefore, hyaluronic acid, which is a polysaccharide polymer, has excellent viscoelasticity and moisturizing ability, It is considered to provide antioxidant and skin moisturizing effect. Therefore, it can be said that the composition containing salmon extract powder and hyaluronic acid as a main ingredient is effective for the hangover phenomenon which occurs after drinking.