• Journal of Ginseng Research
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• 제45권2호
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• pp.246-253
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• 2021

Background: Ginseng is one of the most valuable herbal supplements. It is challenging to perform quality control of ginseng products due to the diversity of bioactive saponins in their composition. Acid or alkaline hydrolysis is often used for the structural elucidation of these saponins and sugars in their side chains. Complete transformation of the original ginsenosides into their aglycones during the hydrolysis is one of the ways to determine a total saponin group content. The main hurdle of this approach is the formation of various by-products that was reported by many authors. Methods: Separate HPLC assessment of the total protopanaxadiol, protopanaxatriol and ocotillol ginsenoside contents is a viable alternative to the determination of characteristic biomarkers of these saponin groups, such as ginsenoside Rf and pseudoginsenoside F₁₁, which are commonly used for authentication of P. ginseng Meyer and P. quinquefolius L. samples respectively. Moreover, total ginsenoside content is an ideal aggregated parameter for standardization and quality control of ginseng-based medicines, because it can be directly applied for saponin dosage calculation. Results: Different hydrolysis conditions were tested to develop accurate quantification method for the elucidation of total ginsenoside contents in herbal products. Linearity, limits of quantification, limits of detection, accuracy and precision were evaluated for the developed HPLC-MS method. Conclusion: Alkaline hydrolysis results in fewer by-products than sugar elimination in acidic conditions. An equimolar response, as a key parameter for quantification, was established for several major ginsenosides. The developed approach has shown acceptable results in the analysis of several different herbal products.

• Biomolecules & Therapeutics
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• 제16권1호
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• pp.28-33
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• 2008

Atorvastatin calcium salt (1) was obtained through the preparation of lactone compound (8) from 2-((4R,6R)-6-(2-(2-(4-fluorophenyl)-5-isopropyl-3-phenyl-4-(phenylcarbamoyl)-1H-pyrrol-1-yl)-ethyl)-2-phenyl-1,3,2-dioxaborinan-4-yl)acetic acid tert-butyl ester (9) by hydrolysis in basic condition. Efficient hydrolysis of boronate compound 9 aimed at the viable synthesis for commercial production and purification of Atorvastatin calcium is reported. Detail studies of evaluation procedure are also reported.

• 한국염색가공학회지
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• 제12권4호
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• pp.233-238
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• 2000

In this study, the control system of sodium hydroxide was demonstrated to systemize hydrolysis process in polyester dyeing. We mainly focused on the application method of acid-alkali titration for the polyester hydrolysis machine of liquor-flow type. Industrial pH meter with electrode type was used for identifying equivalence point. Three units which were analogue-to-digital card, microprocessor and digital output card were used to control NaOH concentration in the control part of the system. The yielded data are translated to the microprocessor through analogue-digital interfacing card. After calculating, NaOH concentration in NaOH storage tank was controlled through the digital output card and solenoid valves.

• Bulletin of the Korean Chemical Society
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• 제11권3호
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• pp.194-200
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• 1990

Various mechanistic aspects of the A2 hydrolysis of methyl acetimidate were explored using the MNDO method. As in thecorresponding reactions of acetamide and methyl carbamate, a proton transfer pre-equilibrium exists between the N-protonated and the O-protonated tautomers, and the subsequent hydrolysis proceeds from the more stable N-protonated form. Of the two reaction pathways, the $A_{AL}2$ path is favored in the gas phase and in concentrated acid solutions, whereas the $A_{AC}2$ path is favored in less acidic solutions with a stable cationic tetrahedral intermediate formed in the rate determining step. Negative charge development on the alkoxy oxygen in the transition state suggested a rate increase with the increase in the electron withdrawing power of the alkoxy group. Calculations on the reaction processes with AM1 indicated that MNDO is more reliable in this type of work, although AM1 is better than MNDO in reproducing hydrogen bonds.

• Bulletin of the Korean Chemical Society
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• 제20권1호
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• pp.59-64
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• 1999

Based on the study of hydrolysis behaviour of U(Ⅵ) ion and major fission product metal ions such as Cs(Ⅰ), Ce(Ⅲ), Nd(Ⅲ), Mo(Ⅵ), Ru(Ⅱ), and ZR(Ⅳ) in the titration media, the performance of noncomplexing-alkalimetric titration method for the determination of free acid in the presence of these metal ions was investigated and its results were compared to those from the completing methods. The free acidities could be determined as low as 0.05 meq in uranium solutions in which the molar ratio of U(Ⅵ)/H+ was less than 5, when the end-point of titration was estimated by Gran plot. The biases in the determinations were less than 1% and about +3% respectively for 0.4 meq and 0.05 meq of free acid at the U(Vl)/H+ molar ratio of up to 5. Applicability of this method to the determination of free acid in spent fuel solutions was confirmed by the analysis of nitric acid content in simulated spent fuel solutions and in a real spent fuel solution.

• Journal of Pharmaceutical Investigation
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• 제11권1호
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• pp.1-5
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• 1981

Through hydrolysis of hydantoin with barium hydroxide amino acid can be prepared. By applying this method new four ${\alpha}-phenyl-cysteine$ derivatives were synthesized.

• 생약학회지
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• 제12권2호
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• pp.88-93
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• 1981

One hundred and forty-four extracts have been tested for the presence of saponins, using the method of froth formation, precipitate formation by acid hydrolysis, Liebermann-Buchard reaction on the acid hydrolysate, and hemolytic activity of the extracts. Among the samples tested, thirteen extracts showed positive saponin reaction in all the tests employed and one hundred and thirty-six showed positive in one or more tests of saponins. The results are tabulated.

• Bulletin of the Korean Chemical Society
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• 제27권2호
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• pp.302-304
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• 2006

• Bulletin of the Korean Chemical Society
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• 제9권4호
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• pp.231-235
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• 1988

Through the Bucherer-Berg method, new 5-alkylthiomethyl or 5-alkylsulfonylmethylhydantoins were prepared. The reaction of ethyl chloroacetate with these compounds gave 3-acetate and the subsequent hydrolysis with dilute sodium hydroxide resulted in 3-hydantoinacetic acid derivatives. These products are expected to exhibit anti-inflammatory and analgestic activities.

• 산업식품공학
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• 제15권1호
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• pp.41-47
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• 2011

쌀부산물인 탈지미강을 상업적으로 사용되는 8가지 protease를 최적화된 조건에서 단일 혹은 혼합 처리하여 수용성 단백질을 분리하였다. 이렇게 분리된 단백질을 Lowry, Kjeldahl 그리고 Gravimetric method 등 총 3가지 방법으로 분석을 한 결과 Protamex, Alcalase, Protease N이 가장 높은 분해율을 나타냈다. 3가지 방법에서 모두 Protamex, Alcalase, Protease N이 가장 높은 분해율을 나타내었고, Gravimetric method의 경우 다른 두 분석방법인 Lowry, Kjeldahl method에 비해 더 높은 단백질 함량을 보였다. 또한 위의 단일처리결과를 바탕으로 3가지 protease를 혼합하여 처리하였을 때 단일효소처리에 비해 상승효과가 나타나는 것을 알 수 있었는데, 이것은 protease의 경우 가수분해 할 수 있는 특정 peptide 혹은 amino acid가 있는데 각각의 protease가 분해하지 못하는 peptide 혹은 amino acid를 서로 분해해줌으로써 상승효과가 나타난 것으로 생각된다. 효소처리를 하여 얻어진 단백질의 사이즈를 알아보기 위해 SDS PAGE를 한 결과 어떠한 밴드도 형성이 되지 않았고 이는 분해된 단백질이 marker의 최소 사이즈인 15 kDa보다 작기때문인 것으로 생각된다. 따라서 일반 단백질보다 사이즈가 작은 polypeptide나 amino acid로써 분해된 것을 뜻하고 실제로 섭취하였을 때는 신체에서 생성되는 단백질 분해효소인 trypsin이나 chymotrypsin의 분해 없이도 쉽게 흡수 할 수 있을 것이라 판단된다. 또한 효소의 종류가 많을수록 총 아미노산의 함량이 높아짐으로써 식품첨가물로써 활용도가 높은 단백질가수분해물로 분해되었음을 확인할 수 있었다.