LIPASE AND ACETYL ESTERASE ACTIVITIES IN INTACT BACILLUS COAGULANS SPORES

1966 ◽  
Vol 44 (6) ◽  
pp. 677-685 ◽  
Author(s):  
Thomas L. Roberts ◽  
Harris Rosenkrantz
Keyword(s):  
Ethyl Acetate ◽  
Ultraviolet Light ◽  
Copper Acetate ◽  
Bacillus Coagulans ◽  
Fluorescein Diacetate ◽  
Ethyl Butyrate ◽  
Acetyl Esterase ◽  
Enzyme Substrates ◽  
Hydrolysis Of ◽  
Esterase Activities

Since data on esterase content of intact dormant spores are meager, a study was carried out with various enzyme substrates and several methods of product detection on intact and ruptured preparations of Bacillus coagulans. Measurement of hydrolysis of triacetin, naphthyl acetates, fluorescein diacetate, ethyl acetate, and ethyl butyrate demonstrated the presence of arylesterase, carboxylesterase, acetyl esterase, and lipase activities in both the intact and ruptured preparations of the non-germinated organism used. It was observed that spore esterase was inhibited by normal and basic copper acetate, eserine, taurocholate, 253.7 mμ ultraviolet light, and temperatures between 50 and 100 °C.

ACETYL ESTERASE IN BACILLUS CEREUS SPORES

1966 ◽  
Vol 44 (6) ◽  
pp. 671-675 ◽  
Author(s):  
Thomas L. Roberts ◽  
Harris Rosenkrantz
Keyword(s):  
Bacillus Cereus ◽  
Enzyme Inhibition ◽  
Esterase Activity ◽  
Fluorescein Diacetate ◽  
Bacterial Spores ◽  
Acetyl Esterase ◽  
Esterase Activities

The paucity of data on esterase activity in intact, dormant spores encouraged further examination of Bacillus cereus spores with more sensitive fluorescent methods. Esterase activities of intact and ballistically ruptured spore preparations against α-naphtyl acetate and fluorescein diacetate in phosphate and carbonate buffers were compared. Enzyme inhibition with toluene and molybdate was also inspected. It was found that intact spores and the supernatant from ruptured spores readily hydrolyzed both acetate substrates. Toluene caused approximately an 80% inhibition, whereas that with molybdate was complete. It was suggested that esterase activity in bacterial spores varies with species.

scholarly journals TESTS FOR HYDROLYSIS OF PEPTIDE BONDS BY ULTRAVIOLET LIGHT

1950 ◽  
Vol 187 (2) ◽  
pp. 543-545
Author(s):  
Dorothy J. McLean ◽  
Arthur C. Giese
Keyword(s):  
Ultraviolet Light ◽  
Peptide Bonds ◽  
Hydrolysis Of

Direct Fluorescent Detection of Organothiophosphorus Pesticides and Some of Their Sulfur-containing Breakdown Products After Thin Layer Chromatography

1967 ◽  
Vol 50 (5) ◽  
pp. 1088-1098
Author(s):  
Mohamed Tawfik H Ragab
Keyword(s):  
Thin Layer ◽  
Ethyl Acetate ◽  
Thin Layer Chromatography ◽  
Ultraviolet Light ◽  
Congo Red ◽  
Fluorescent Detection ◽  
Bromine Vapor ◽  
Layer Chromatography ◽  
Sulfur Containing ◽  
Dark Blue

Abstract A rapid, simple, convenient, and widely applicable method for the direct fluorescent detection of organothiophosphorus pesticides and some postulated breakdown products of these compounds is presented. The coinpounds were spotted on thin layer chromatographic sheets, developed in ethyl acetate :nhexane, and made visible by exposure to bromine vapor followed by spraying with ferric chloride and 2-(o-hydroxy phenyl) benzoxazole. Of the 47 compounds tested, 32 compounds produced fluorescent blue spots vinder longwave ultraviolet light; these consisted of 25 organothiophosphorus pesticides, 5 sulfur-containing breakdown products, and phosphoric and hypophosphorous acids. A superimposed Congo red spray destroyed the fluorescence and resulted in dark blue spots against a red backgrovind. The sensitivity of this method is in the range of 0.2 to 5.0 μg, depending on the specific compound.

scholarly journals HPTLC determination of diosgenin in fenugreek seeds

2018 ◽  
Vol 68 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Barbara Król-Kogus ◽  
Khenifi Mohammed Lamine ◽  
Piotr Migas ◽  
Messaoud Boudjeniba ◽  
Mirosława Krauze-Baranowska
Keyword(s):  
Ethyl Acetate ◽  
Acid Hydrolysis ◽  
Methanolic Extract ◽  
Soxhlet Extraction ◽  
African Origin ◽  
Fenugreek Seeds ◽  
Hydrolysis Products ◽  
Hydrolysis Of

Abstract A new HPTLC-densitometric method for diosgenin determination in fenugreek seeds was established after optimization of the conditions for efficient saponin extraction and acid hydrolysis. Several procedures were tested, the best of which was a three-step Soxhlet extraction, followed by hydrolysis of the obtained methanolic extract with 2 mol L-1 H2SO4. Best diosgenin separation from other hydrolysis products was obtained on HPTLC Si60F254 plates u sing a mixture of n-heptane/ethyl acetate (7:3, V/V) and modified anisaldehyde as a spraying reagent. The method was preliminarily validated and the determined amounts of diosgenin in fenugreek seeds of Polish and African origin were found to be similar and ranged from 0.12-0.18 %.

A Qualitative Gas Chromatographic Analysis of Substituted 5,6-Dihydroxyindoles from the Urine of Patients with Melanoma

1981 ◽  
Vol 67 (4) ◽  
pp. 325-332 ◽  
Author(s):  
Stanislav Pavel ◽  
Frits A. J. Muskiet ◽  
Alena Budešínská ◽  
Jirí Duchon
Keyword(s):  
Ethyl Acetate ◽  
Chromatographic Analysis ◽  
Helix Pomatia ◽  
Nitrogen Atmosphere ◽  
Spectrometric Analysis ◽  
Gas Chromatographic Analysis ◽  
Indolic Compounds ◽  
Hydrolysis Of ◽  
Ethyl Acetate Extracts ◽  
Chromatographic Mass

A qualitative gas chromatographic analysis of trimethylsilylated ethyl acetate extracts of melanotic urine revealed 5 indolic compounds, which have been identified as substituted 5,6-dihydroxyindoles. Ethyl acetate extracts of melanotic urines at pH 2.0 contained isomeric 5-hydroxy-6-methoxy and 6-hydroxy-5-methoxy-indolyl-2-carboxylic acids which were not separable under the conditions used. A careful hydrolysis of melanotic urine with a Helix pomatia preparation followed by extraction at pH 6.5 in a nitrogen atmosphere released 3 additional indolic compounds from their conjugated form. Using gas chromatographic-mass spectrometric analysis they were identified as 5-hydroxy-6-methoxy, 6-hydroxy-5-methoxyindole and 5,6-dihydroxyindole.

scholarly journals O-acetylated Gangliosides as Targets for Cancer Immunotherapy

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 741 ◽  
Author(s):  
Sumeyye Cavdarli ◽  
Philippe Delannoy ◽  
Sophie Groux-Degroote
Keyword(s):  
Cancer Immunotherapy ◽  
Current Knowledge ◽  
Cancer Development ◽  
Acetyl Esterase ◽  
Pathological Conditions ◽  
Ganglioside Biosynthesis ◽  
The Central Nervous System ◽  
Neuroectodermal Origin ◽  
Ganglioside Species ◽  
Esterase Activities

O-acetylation of sialic acid residues is one of the main modifications of gangliosides, and modulates ganglioside functions. O-acetylation of gangliosides is dependent on sialyl-O-acetyltransferases and sialyl-O-acetyl-esterase activities. CAS1 Domain-Containing Protein 1 (CASD1) is the only human sialyl-O-acetyltransferases (SOAT) described until now. O-acetylated ganglioside species are mainly expressed during embryonic development and in the central nervous system in healthy adults, but are re-expressed during cancer development and are considered as markers of cancers of neuroectodermal origin. However, the specific biological roles of O-acetylated gangliosides in developing and malignant tissues have not been extensively studied, mostly because of the requirement of specific approaches and tools for sample preparation and analysis. In this review, we summarize our current knowledge of ganglioside biosynthesis and expression in normal and pathological conditions, of ganglioside O-acetylation analysis and expression in cancers, and of the possible use of O-acetylated gangliosides as targets for cancer immunotherapy.

A self-confinement synthesis of a POM-decorated MOF thin film for actively hydrolyzing ethyl acetate

2020 ◽  
Vol 56 (89) ◽  
pp. 13840-13843
Author(s):  
Zhou Fang ◽  
Danke Chen ◽  
Zhuoyi Li ◽  
Xu Ma ◽  
Xinyi Wan ◽  
...  
Keyword(s):  
Thin Film ◽  
Ethyl Acetate ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Hydrolysis Of Esters ◽  
Hydrolysis Of

A solid acid catalyst POM@MOF thin film was prepared and utilized for the efficient hydrolysis of esters with a long durability.

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