• Title/Summary/Keyword: weak acid hydrolysis

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Synthesis of trifluoromethylated dihydro-1,4-dithiin carboxamides and their antifungal activities (Trifluoromethylated Dihydro-1,4-dithiin carboxanilide 유도체의 합성 및 살균활성)

  • Hahn, Hoh-Gyu;Nam, Kee-Dal;Chang, Kee-Hyuk;Lee, Seon-Woo;Cho, Kwang-Yun
    • The Korean Journal of Pesticide Science
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    • v.5 no.2
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    • pp.26-32
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    • 2001
  • [ ${\alpha},{\beta}$ ]-Unsaturated carboxamides 12 with trifluromethylated dihydro-1,4-dithiins were synthesized for the purpose of development of new agrochemical fungicide. Chlorination of trifluoromethylated ${\beta}$-ketoester 4 followed by tile reaction with 1,2-ethanedithiol gave intermediate 1,4-dithiane 9. Without purification of 9 substitution of hydroxy by chlorine followed by dehydrochlorination in the presence of triethylamine afforded trifluoromethylated dihydro-1,4-dithiin ethyl ester 7. Activation of the hydroxy of the carboxylic acid 10 obtained from the hydrolysis of 7 and then reacted with various amines gave the corresponding trifluoromethylated dihydro-1,4-dithiin carboxamides. Antifungal screening (in vivo) against typical plant diseases, Rice Blast, Rice Sheath Blight, Cucumber Gray Mold, Tomato Late Blight, Wheat Leaf Rust, and Barley Powdery Mildew of the synthesized compounds was carried out. As a result, most of the compounds shlowed weak antifungal activities and some compounds in which isopropyl group was substituted in meta of the phenyl showed antifungal activity (99%) at 250 ppm against the disease Wheat Leaf Rust.

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Effect of Biomass-derived Inhibitors on Ethanol Production (바이오매스 유래의 저해물질이 에탄올 생산에 미치는 영향)

  • Lee, Myung-Gu;Cho, Dae-Haeng;Kim, Yong-Hwan;Lee, Jin-Won;Lee, Jong-Ho;Kim, Seung-Wook;Cho, Jae-Hoon;Lee, Do-Hoon;Kim, Sang-Yong;Park, Chul-Hwan
    • KSBB Journal
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    • v.24 no.5
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    • pp.439-445
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    • 2009
  • The process for ethanol production requires lignocellulosic biomass to be hydrolyzed to generate monomeric sugars for the fermentation. During hydrolysis step, a monomeric sugars and a broad range of inhibitory compounds (furan derivatives, weak acids, phenolics) are formed and released. In this study, we investigated the effects of inhibitory compounds on the fermentative performance of Saccharomyces cerevisiae K35 and Pichia stipitis KCCM 12009 in ethanol production, two yeast strains were fermented in the synthetic medium including six inhibitory compounds such as 5-hydroxymethylfurfura (5-HMF), furfural, acetic acid, syringaldehyde, vanillic acid and syringic acid. Ethanol of over 40 g/L was produced by two yeast strains in the absence of inhibitory compounds, respectively. Most inhibitory compounds except acetic acid had a little effect on the ethanol production, but acetic acid showed high inhibition effect on the cell growth and ethanol production.

Evaluation of the Anti-oxidant Activity of Pueraria Extract Fermented by Lactobacillus rhamnosus BHN-LAB 76 (Lactobacillus rhamnosus BHN-LAB 76에 의한 Pueraria 발효 추출물의 항산화 활성 평가)

  • Kim, Byung-Hyuk;Jang, Jong-Ok;Lee, Jun-Hyeong;Park, Ye-Eun;Kim, Jung-Gyu;Yoon, Yeo-Cho;Jeong, Su Jin;Kwon, Gi-Seok;Lee, Jung-Bok
    • Journal of Life Science
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    • v.29 no.5
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    • pp.545-554
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    • 2019
  • The phytochemical compounds of Pueraria, a medicinally important leguminous plant, include various isoflavones that have weak estrogenic activity and a potential role in preventing chronic disease, cancer, osteoporosis, and postmenopausal syndrome. However, the major isoflavones are derivatives of puerarin and occur mainly as unabsorbable and biologically inactive glycosides. The bioavailability of the glucosides can be increased by hydrolysis of the sugar moiety using ${\beta}$-glucosidase. In this study, we investigated the antioxidant effects of a Pueraria extract after fermentation by Lactobacillus rhamnosus BHN-LAB 76. The L. rhamnosus BHN-LAB 76 strain was inoculated into Pueraria powder and fermented at $37^{\circ}C$ for 72 hr. The total polyphenol content of the Pueraria extract increased by about 134% and the total flavonoid content increased around 110% after fermentation with L. rhamnosus BHN-LAB 76 when compared to a non-fermented Pueraria extract. Superoxide dismutase-like activities, DPPH radical scavenging, and ABTS radical scavenging increased by approximately 213%, 190%, and 107%, respectively, in the fermented Pueraria extract compared to the non-fermented Pueraria extract. Fermentation of Pueraria extracts with L. rhamnosus BHN-LAB 76 is therefore possible and can effectively increase the antioxidant effects. These results can be applied to the development of improved foods and cosmetic materials.