• 공업화학
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• 제16권5호
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• pp.705-711
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• 2005

프로테아제인 subtilisin A를 이용하여 유기 용매 안에서 당에스테르인 라우르산부틸에스테르를 합성하였다. 높은 수율을 얻을 수 있기 때문에 유기 용매로는 피리딘이 주로 사용되었으나 냄새가 심하여 식품과 의약품에 사용되는 당에스테르를 합성하는 데에는 적합하지 않다. 그러므로 이를 대체할 유기 용매를 선정하기 위하여 여러 유기 용매 안에서 당에스테르를 효소 합성하였으나 피리딘에 미치지 못하였다. 이에 피리딘을 근거로 하는 W/O 마이크로에멀젼을 만들어 당에스테르를 합성하였는데, Tween 60, Brij 56, 1-O-octyl-${\beta}$-D-glucopyranose과 같은 비이온 계면활성제를 사용하였을 때 수율이 우수하였다.

• Journal of Microbiology and Biotechnology
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• 제27권8호
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• pp.1392-1400
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• 2017

Galactooligosaccharides (GOSs) are known to be selectively utilized by Bifidobacterium, which can bring about healthy changes of the composition of intestinal microflora. In this study, ${\beta}-GOS$ were synthesized using bifidobacterial ${\beta}-galactosidase$ (G1) purified from recombinant E. coli with a high GOS yield and with high productivity and enhanced bifidogenic activity. The purified recombinant G1 showed maximum production of ${\beta}-GOSs$ at pH 8.5 and $45^{\circ}C$. A matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the major peaks of the produced ${\beta}-GOSs$ showed MW of 527 and 689, indicating the synthesis of ${\beta}-GOSs$ at degrees of polymerization (DP) of 3 and DP4, respectively. The trisaccharides were identified as ${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-glucopyranose, and the tetrasaccharides were identified as ${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-glucopyranose. The maximal production yield of GOSs was as high as 25.3% (w/v) using purified recombinant ${\beta}-galactosidase$ and 36% (w/v) of lactose as a substrate at pH 8.5 and $45^{\circ}C$. After 140 min of the reaction under this condition, 268.3 g/l of GOSs was obtained. With regard to the prebiotic effect, all of the tested Bifidobacterium except for B. breve grew well in BHI medium containing ${\beta}-GOS$ as a sole carbon source, whereas lactobacilli and Streptococcus thermophilus scarcely grew in the same medium. Only Bacteroides fragilis, Clostridium ramosum, and Enterobacter cloacae among the 17 pathogens tested grew in BHI medium containing ${\beta}-GOS$ as a sole carbon source; the remaining pathogens did not grow in the same medium. Consequently, the ${\beta}-GOS$ are expected to contribute to the beneficial change of intestinal microbial flora.

• Journal of Forest and Environmental Science
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• 제13권1호
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• pp.153-165
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• 1997

본 논문에서는 케미루민센스와 HPLC를 사용하여 산소 표백시 수산기 라디칼의 생성과 리그닌 및 탄수화물의 분해와의 상호관련성을 밝히기 위하여 간단한 리그닌 모델화합물인 아포사이놀과 탄수화물 모델화합물인 $\alpha$-D-glucopyranose와 methyl-$\beta$-D-glucopyronoside를 사용하여 연구하였다. 또한 수산기 라디칼의 생성과 금속이온과의 연관성을 검토하고 탈리그닌을 촉진함과 동시에 탄수화물의 분해를 억제하는 최적의 금속이온 농도를 조사하였다. 그 결과 금속이온의 존재가 수산기 라디칼의 형성과 탈리그닌화에 효과적인 영향을 주며, $Cu^{2+}$ > $Mn^{2+}$ > $Mg^{2+}$ > $Fe^{2+}$의 순서로 수산기 라디칼이 생성됨을 알 수 있었다. 이러한 금속이온들은 탄수화물도 분해시키는 문제가 있음을 증명하였다. 그러나 $100{\mu}m\;Mg^{2+}$를 첨가하면 수산기 라디칼의 생성이 억제됨을 알 수 있었다. 또한 $Cu^{2+}$은 탄수화물의 안정성에 나쁜 영향을 미쳤으나, $3{\mu}m\;Mn^{2+}$을 첨가하면 놀랍게도 methyl-$\beta$-D-glucopyranoside에 대해 약간의 보호효과를 나타냄을 알 수 있었다. 이산화염소 라디칼 표백 용액 중에서는 이와 반대로 금속과 관계없이 상당한 양의 수산기 라디칼을 생성하지 않으나 이산화염소 자체의 라디칼이 리그닌만을 선택적으로 분해하였다.

• Archives of Pharmacal Research
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• 제28권3호
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• pp.280-284
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• 2005

The chromatographic separation of the MeOH extract from the aerial parts of Syneilesis palmata led to the isolation of a new sesquiterpene glycoside 4, together with four known compounds. Their structures were characterized to be 4$\beta$,5$\beta$-epoxy-caryophill-8,(15)-ene (1), 3$\beta$­hydroxy-gultin-5-ene (2), 4$\alpha$,5$\beta$-dihydroxy-caryophill-8,(15)-ene (3), (-)-oplopan-4-one-10-$\alpha$-O­$\beta$-D-glucose (4) and 3-hexenyl-1-O-$\beta$-D-glucopyranose (5), based on spectroscopic and chemical methods. Compound 2 showed moderate cytotoxicity against five human tumor cell lines in vitro with its EDso values ranging from 5.90-1 0.83 $\mu$g/mL.

• 한국미생물·생명공학회지
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• 제24권2호
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• pp.137-142
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• 1996

The biosynthesis and catabolite repression of cyclodextrin glucanotransferase(CGTase) and cyclodextrinase(CDase) were studied in Bacillus sp. KJI6. In accompanying to the cell growth, CGTase was synthesized during early growth phase (20h culture) and CDase was synthesized during late growth phase (60h culture). Synthesis of CGTase was rather constitutive than that of CDase in the absence or presence of carbon source. Production of CDase was strongly stimulated by amylopectin and $\gamma$-CD medium (about 6 times), but CGTase synthesis was slightly increased (about 1.3 times). Easily metabolizable carbohydrates such as D-glucose, D- fructose and D-mannose completely repressed the expression of CDase, whereas their repressive effect to CGTase synthesis was relatively negligible. By addition of 10 mM cAMP, any significant effect on the synthesis of the two enzymes was not observed. Hardly metabolizable glucose analogues such as 2-deoxy-D-glucose and 3-0-methyl-D-glucopyranose also did not show any repression on the syntheses of CGTase and CDase. This indicates that D-glucose has to be metabolized to exert its repressive effect. With these results, it seems likely that the biosynthesis of CGTase and CDase are regulated by the catabolite repression due to unknown metabolite(s) of EM pathway.

• 환경위생공학
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• 제20권2호
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• pp.33-38
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• 2005

Chitosan is a dietary fiber because of a linear polysaccharide composed of $\beta-(1{\rightarrow}4)$-linked 2-amino-2-deoxy-D-glucopyranose. In this study, control release system of vitamin C has been estimated in chitosan molecular network as a vitamin C carrier of controlled release. The amount of released vitamin C were decreased in higher amount of chitosan concentration. Especially, vitamin C were slowly released from chitosan solution in dialysis membrane when compared with vitamin C solution alone in dialysis membrane. These result assumed that chitosan driving force is dependent on chitosan molecular weight and cationic property of amino group with anionic property of vitamin C.

• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 추계 총회 및 학술발표회
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• pp.82-85
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• 1998

1. 서론 : Cyclodextrin(CD) 동족체(homologues)는 $\alpha$-, $\beta$-, $\gamma$-CD로 구분되며, 이들 각각은 $\alpha$-D-glucopyranose 단위체 6,7, 및 8개가 비환원성 환상구조로 연결된 cyclic maltooligosaccaride의 일종으로 외부는 친수성이고, 내부는 소수성인 공동 구조를 갖고 있다. 따라서 각 CD는 동공의 크기가 달라 다른 크기의 소수성 물질들과 선택적인 포접화합물 (inclusion compound)을 형성하는 특징이 있다. CD 동족체는 전분 분해 효소인 cyclodextrin glycosyltransferase(CGTase)에 의해 전분으로부터 생산되는데, 반응용액 내에서의 CD 동족체 농도가 어느 한계값 이상으로 높아지면 생산물 저해와 다른 환원당으로의 분해 때문에 생산성이 감소하여 이의 효과적 생산에 어려움이 있다. 본 연구는 dead-end 및 cross-flow형 막 생물반응기를 사용하여 CGTase에 의한 전분의 CD 동족체로의 분해반응시 생산물 저해를 억제시켜 생산성을 향상시키고, 동시에 조작조건 변화에 따른 생산물인 CD 동족체의 효과적인 연속분리 가능성을 검토하였다.

• Natural Product Sciences
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• 제6권4호
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• pp.193-198
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• 2000

Phytochemical study of the constitutive polyphenolics of the flower aqueous alcohol extract of Tamarix tetragyna was carried out. The new sulphated flavonol, quercetin 3',4'-dimethyl ether $3-O-KSO_3$ as well as the new natural galloyl glucose, $2-O-galloyl-({\alpha}/{\beta})-^4C_1-glucopyranose$ were isolated and characterized. The known sulphated flavonols, kaempferol 7,4-dimethyl ether $3,5-di-O-KSO_3$, quercetin 7-methyl ether $3,3',4'-tri-O-KSO_3$, quercetin 7,4'-dimethyl ether $3-O-KSO_3$ and quercetin $3-O-KSO_3$ and the known sulphated phenolics, isoferulic acid $3-O-KSO_3$ and ellagic acid 4,4'-dimethyl ether $3-O-KSO_3$ were also separated and identified. The structures were established by conventional methods of analysis and confirmed by $^1H-,\;^{13}C-NMR$ and negative ESI-mass spectrometry. 2D-homonuclear chemical shift correlation NMR experiment was applied for the new natural galloylglucose.

• Journal of Microbiology and Biotechnology
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• 제18권9호
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• pp.1544-1549
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• 2008

MhMTS and MhMTH are trehalose ($\alpha$-D-glucopyranosyl-[1,1]-$\alpha$-D-glucopyranose) biosynthesis genes of the thermophilic microorganism Metallosphaera hakonensis, and encode a maltooligosyltrehalose synthase (MhMTS) and a maltooligosyltrehalose trehalohydrolase (MhMTH), respectively. In this study, the two genes were fused in-frame in a recombinant DNA, and expressed in Escherichia coli to produce a bifunctional fusion enzyme, MhMTSH. Similar to the two-step reactions with MhMTS and MhMTH, the fusion enzyme catalyzed the sequential reactions on maltopentaose, maltotriosyltrehalose formation, and following hydrolysis, producing trehalose and maltotriose. Optimum conditions for the fusion enzyme-catalyzed trehalose synthesis were around $70^{\circ}C$ and pH 5.0-6.0. The MhMTSH fusion enzyme exhibited a high degree of thermostability, retaining 80% of the activity when pre-incubated at $70^{\circ}C$ for 48 h. The stability was gradually abolished by incubating the fusion enzyme at above $80^{\circ}C$. The MhMTSH fusion enzyme was active on various sizes of maltooligosaccharides, extending its substrate specificity to soluble starch, the most abundant natural source of trehalose production.

• 한국식품저장유통학회지
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• 제12권6호
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• pp.656-661
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• 2005

목초액을 천연보존료로 이용하기 위하여 기계식전용 탄화로에서 제조된 목초액을 대상으로 이화적인 특성 및 휘발성분의 함량을 분석하여 다음과 같은 결과를 얻었다. 목초액은 pH, 비중, 산도, 굴절률, 투과률은 각각 2.40, 1.020, $0.8\%$, $1.354\%$, $89.05\%$이었고, 용해타르 및 작열잔사는 각각 $2.31\%,\;0.008\%$이었다. 한편 무기성분은 Al 0.11, Cu 4.13, Fe 2.92, Mn 0.15, Zn 4.37, Ca 3.49, K 5.89, Mg 0.43, Na 6.88 mg/L 함유하고 있었으나 유해중금속인 Pb, Cd, As, Hg, Cr 등은 검출되지 않았다. GC-MS에 의한 목초액의 성분을 분석한 결과 유기성 분획에 함유된 화합물은 ketones 및 diketone계 화합물이 5,472.3 ${\mu}g/100mg$, phenol류가 5,170.3 ${\mu}g/100mg$, methoxyphenol 화합물이 6,002.7 ${\mu}g/100mg$, dimethoxyphenol 화합물이 5,790.7 ${\mu}g/100mg$, furan 및 pyran 화합물이 5,604.5 ${\mu}g/100mg$, pyrocatechol류가 4,790.3 ${\mu}g/100mg$ 함유되어 있었다. 성분별로는 2, 6-dimethoxyphenol (syringol) 3,453 ${\mu}g/100mg$으로 가장 높은 함량을 나타냈고, 2-hydroxy-2-cyclopenten-1-one 2,480.3 ${\mu}g/100mg$, catechol 2,097.5 ${\mu}g/100mg$, Phenol 2,037.2 ${\mu}g/100mg$, 2(5H)-furanone 1,826.7 ${\mu}g/100mg$, 2-methoxyphenol (guaiacol) 1,812.9 ${\mu}g/100mg$, 5-hydro-2-furancarboxaldehyde (HMF) 1,636.8 ${\mu}g/100mg$함유되어 있었다. 수용성 분획에서는 catechol 501.2 ${\mu}g/100mg$, cyclopropyl carbinol 442.0 ${\mu}g/100mg$, 2-hydroxy-2-cyclopenten-1-one 270.0 ${\mu}g/100mg$, 5-hydro-2-furancarboxaldehyde 120.5 ${\mu}g/100mg$, 1,4:3,6-dianhydro-$\alpha$-d-glucopyranose 121.9 ${\mu}g/100mg$ 함유되어 있었다.