scholarly journals Acetyltransferase activity in Pseudomonas sp. capable of acetylating the C-4 hydroxyl group of nivalenol-type trichothecenes

2016 ◽  
Vol 62 (6) ◽  
pp. 326-329 ◽  
Author(s):  
Akira Tanaka ◽  
Shohei Saikawa ◽  
Takuro Suzuki ◽  
Akinobu Echigo ◽  
Kazuyuki Maeda ◽  
...  
Keyword(s):  
Hydroxyl Group ◽  
Acetyltransferase Activity

Detection method of combustion oscillation characteristics under strong noise background

2020 ◽  
Vol 21 (6) ◽  
pp. 612
Author(s):  
Yunkun Wei ◽  
Tianhong Zhang ◽  
Zhonglin Lin ◽  
Qi Xie ◽  
Yan Zhang
Keyword(s):  
Radiation Thermometry ◽  
Hydroxyl Group ◽  
Interference Signal ◽  
Engine Vibration ◽  
Combustion Technology ◽  
Lean Fuel ◽  
Combustion Oscillation ◽  
Aero Engines ◽  
Temperature Measurement System ◽  
Multispectral Radiation Thermometry

After the lean fuel premixed combustion technology is applied to aero engines, severe combustion oscillations will be cased and led to hidden safety hazards such as engine vibration, further energy waste and other problems. Therefore, it is increasingly important to actively control combustion oscillations. In this paper, a multispectral radiation thermometry (MRT) is used to analyze the hydroxyl group, which is a measurable research object in the combustion chamber of an aero engine, and to fit the functional relationship between the radiation intensity ratio and the temperature in different bands. The theoretical value of the error is <2%. At the same time, in order to solve the problem of weak detection signal and excessive interference signal, an improved frequency domain filtering method based on fast Fourier transform is designed. Besides, the FPGA platform is used to ensure the real-time performance of the temperature measurement system, and simulations and experiments are performed. An oscillating signal with an oscillation frequency of 315 Hz is obtained on the established test platform, and the error is only 1.42%.

CONTEXTUAL LEARNING IN THE MORRIS WATER MAZE

2018 ◽  
pp. 13-20
Author(s):  
Е.И. Захарова ◽  
З.И. Сторожева ◽  
А.Т. Прошин ◽  
М.Ю. Монаков ◽  
А.М. Дудченко
Keyword(s):  
Morris Water Maze ◽  
Choline Acetyltransferase ◽  
Water Maze ◽  
Synaptic Membranes ◽  
Projection Neurons ◽  
Synaptic Organization ◽  
Acetyltransferase Activity ◽  
Cholinergic Interneurons ◽  
Late Stages ◽  
Choline Acetyltransferase Activity

Цель - исследование холинергической синаптической организации функций обучения и памяти у крыс с разными когнитивными способностями. Методы. Крыс обучали на пространственной обстановочной модели в водном лабиринте Морриса. Через 2-3 сут. после окончания тренировок животных декапитировали, из неокортекса и гиппокампа с помощью центрифугирования выделяли субфракции синаптических мембран и синаптоплазмы легких и тяжелых синаптосом. В синаптических субфракциях определяли активность ключевого фермента холинергических нейронов холинацетилтрансферазы (ХАТ). Сравнивали результаты тестирования (время достижения скрытой платформы) и активность фермента у способных и неспособных к обучению крыс. Результаты. Были выявлены: 1) различия в холинергической организации исследованных функций в процессе обучения у способных и неспособных к обучению крыс, в том числе: положительные корреляции активности ХАТ в синапсах проекционных нейронов неокортекса у способных крыс со временем достижения платформы на промежуточных этапах обучения и в синапсах проекционных нейронов гиппокампа у неспособных крыс на позднем этапе обучения; разнонаправленные корреляции активности ХАТ в синапсах, предположительно, интернейронов гиппокампа (фракция тяжелых синаптосом) у способных и неспособных крыс на начальном и позднем этапах обучения; 2) индивидуальность холинергической организации функций на всех этапах обучения. Выводы. Полученные данные свидетельствуют в пользу представлений о специфике холинергической организации функций пространственного обстановочного обучения у крыс с выраженными и слабыми способностями к обучению, а также избирательной роли холинергических интернейронов гиппокампа на исходном этапе обучения и в консолидации памяти. In order to expand the knowledge about neuronal organization of the cognitive functions required for understanding plastic processes in the brain, we investigated the cholinergic synaptic organization of learning and memory functions in rats with different cognitive abilities. Methods. Rats were trained on a contextual situation model in the Morris water maze. At 2-3 days after the end of training, animals were decapitated, and subfractions of synaptic membranes and synaptoplasm of light and heavy synaptosomes were isolated from the cortex and the hippocampus by centrifugation. In synaptic subfractions, activity of the key enzyme of cholinergic neurons, choline acetyltransferase, was measured. We compared the test results (latent period to reach the hidden platform) and the enzyme activity in capable (lower quartile) and incapable of learning rats (upper quartile). Results. The following was found: 1) differences in the cholinergic organization of studied functions in capable and uncapable of learning rats during training, including: positive correlations of choline acetyltransferase activity in synapses of projection neurons in the cortex of capable rats with latency to reach the platform at intermediate stages of training and in the hippocampus ofincapable rats at late stages of training; multidirectional correlations of choline acetyltransferase activity in synapses of hippocampal, presumably, interneurons (heavy synaptosomes) in capable and incapable rats at early and late stages of training; 2) distinctness of the cholinergic organization of functions at all stages of training. Conclusions. The study demonstrated for the first time a specificity of the cholinergic organization of functions in spatial situational learning of rats with strong and poor learning abilities and a selective role of hippocampal cholinergic interneurons at the initial stage of learning and in memory consolidation.

α-Glucosidase Inhibition and Docking Studies of 5-Deoxyflavonols and Dihydroflavonols Isolated from Abutilon pakistanicum

2019 ◽  
Vol 23 (17) ◽  
pp. 1857-1866
Author(s):  
Munawar Hussain ◽  
Zaheer Ahmed ◽  
Shamsun N. Khan ◽  
Syed A. A. Shah ◽  
Rizwana Razi ◽  
...  
Keyword(s):  
Methanolic Extract ◽  
Docking Studies ◽  
Hydroxyl Group ◽  
Coumaric Acid ◽  
In Vitro Activity ◽  
Aerial Parts ◽  
First Time ◽  
Acid Esters ◽  
Phenol Moiety

Three new 5-deoxyflavonoid and dihydroflavonoids 2, 3 and 4 have been isolated from the methanolic extract of Abutioln pakistanicum aerial parts, for which structures were elucidated explicitly by extensive MS- and NMR-experiments. In addition to these, 3,7,4′-trihydroxy-3′-methoxy flavonol (1) is reported for the first time from Abutioln pakistanicum. Compound 2 and 4 are p-coumaric acid esters while compounds 2–4 exhibited α-glucosidase inhibitory activity. Docking studies indicated that the ability of flavonoids 2, 3 and 4 to form multiple hydrogen bonds with catalytically important residues is decisive hence is responsible for the inhibition activity. The docking results signified the observed in-vitro activity quite well which is in accordance with previously obtained conclusion that phenol moiety and hydroxyl group are critical for the inhibition of α-glucosidase enzyme.

Combinatorial Synthesis of Novel 9R-Acyloxyquinine Derivatives as Insecticidal Agents

2020 ◽  
Vol 23 (2) ◽  
pp. 111-118
Author(s):  
Zhiping Che ◽  
Jinming Yang ◽  
Di Sun ◽  
Yuee Tian ◽  
Shengming Liu ◽  
...  
Keyword(s):  
Natural Products ◽  
Double Bond ◽  
Insecticidal Activity ◽  
Structural Modification ◽  
Combinatorial Synthesis ◽  
Hydroxyl Group ◽  
Botanical Insecticide ◽  
Mythimna Separata ◽  
Lead Compounds

Background: It is one of the effective ways for pesticide innovation to develop new insecticides from natural products as lead compounds. Quinine, the main alkaloid in the bark of cinchona tree as well as in plants in the same genus, is recognized as a safe and potent botanical insecticide to many insects. The structural modification of quinine into 9R-acyloxyquinine derivatives is a potential approach for the development of novel insecticides, which showed more toxicity than quinine. However, there are no reports on the insecticidal activity of 9Racyloxyquinine derivatives to control Mythimna separata. Methods: Endeavor to discover biorational natural products-based insecticides, 20 novel 9Racyloxyquinine derivatives were prepared and assessed for their insecticidal activity against M. separata in vivo by the leaf-dipping method at 1 mg/mL. Results: Among all the compounds, especially derivatives 5i, 5k and 5t exhibited the best insecticidal activity with final mortality rates of 50.0%, 57.1%, and 53.6%, respectively. Conclusion: Overall, a free 9-hydroxyl group is not a prerequisite for insecticidal activity and C9- substitution is well tolerated; modification of out-ring double-bond is acceptable, and hydrogenation of double-bond enhances insecticidal activity; Quinine ring is essential and open of it is not acceptable. These preliminary results will pave the way for further modification of quinine in the development of potential new insecticides.

The Influence of Hydrogen atoms on the Performance of Radial Distribution Function Based Descriptors in the Chemoinformatic Studies of HIV-1 Prote-ase Complexes with Inhibitors.

2020 ◽  
Vol 17 ◽  
Author(s):  
Jurica Novak ◽  
Maria A. Grishina ◽  
Vladimir A. Potemkin
Keyword(s):  
Distribution Function ◽  
Radial Distribution Function ◽  
Radial Distribution ◽  
Current Model ◽  
Direct Interaction ◽  
Hydroxyl Group ◽  
Linear Regression Method ◽  
Hydrogen Atoms ◽  
Protease Enzyme ◽  
Hiv 1

: In this letter the newly introduced approach based on the radial distribution function (RDF) weighted by the number of va-lence shell electrons is applied for a series of HIV-1 protease enzyme and its complexes with inhibitors to evaluate the influ-ence of hydrogen atoms on the performance of the model. The multiple linear regression method was used for the selection of the relevant descriptors. Two groups of residues having dominant contribution to the RDF descriptor are identified as relevant for the inhibition. In the first group are residues like Arg8, Asp25, Thr26, Gly27 and Asp29, which establish direct interaction with the inhibitor, while the second group consists of the amino acids at the interface of the two homodimer sub-units or with the solvent. The crucial motif pointed out by our approach as the most important for inhibition of the enzyme’s activity and present in all inhibitors is hydroxyl group that establish hydrogen bond with Asp25 side chain. Additionally, the comparison to the model without hydrogen showed that both models are of similar quality, but the downside of the current model is the need for the determination of residues’ protonation states.

Sign in / Sign up

Export Citation Format

Share Document