scholarly journals Inhibition of Lipoxygenase and Peroxidase Reaction by Some Flavonols and Flavones: The Structure-Activity Relationship

2017 ◽  
Vol 12 (11) ◽  
pp. 1934578X1701201
Author(s):  
Zbigniew Sroka ◽  
Alina Sowa ◽  
Andrzej Dryś
Keyword(s):  
Correlation Coefficient ◽  
Antioxidant Properties ◽  
Structure Activity Relationship ◽  
Methoxyl Group ◽  
Activity Relationship ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Peroxidase Reaction ◽  
Structure Activity ◽  
Reducing Properties

Some flavonoids were investigated for their effects on lipoxygenase and peroxidase. The strongest inhibitor of lipoxygenase was kaempferol with one hydroxyl group situated at the 4’ position in the B ring, with activity of 21.2±2.03 calculated per μmole of compound. The weakest inhibition was observed for diosmetin with a hydroxyl group at the 3′ position and a methoxyl group at 4′ in the B ring, with activity of 1.17±0.77 per μmole. Peroxidase was most strongly inhibited by quercetin (22.7±0.05) with two hydroxyl groups in the B ring at 3′ and 4′. The weakest inhibitor of peroxidase was genkwanin (0±0.16) with one hydroxyl group at position 4′ in the B ring and methoxyl at position 7 in the A ring. The correlation coefficient between reduction of Fe3+ by flavonoids and inhibition of lipoxygenase by these compounds was 0.72 and the reduction of Fe3+ and inhibition of peroxidase was 0.24. The results show that inhibition of peroxidase is weakly associated with reducing properties of phenols and inhibition of lipoxygenase may be associated with antioxidant properties of flavonoids.

scholarly journals Flavonoids from the Genus Euphorbia: Isolation, Structure, Pharmacological Activities and Structure–Activity Relationships

2021 ◽  
Vol 14 (5) ◽  
pp. 428
Author(s):  
Douglas Kemboi Magozwi ◽  
Mmabatho Dinala ◽  
Nthabiseng Mokwana ◽  
Xavier Siwe-Noundou ◽  
Rui W. M. Krause ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Antioxidant Properties ◽  
Structure Activity Relationship ◽  
Biological Properties ◽  
Therapeutic Agents ◽  
Skeletal Structure ◽  
Activity Relationship ◽  
Hydroxyl Groups ◽  
Structure Activity ◽  
Review Reports

Plants of the genus Euphorbia are widely distributed across temperate, tropical and subtropical regions of South America, Asia and Africa with established Ayurvedic, Chinese and Malay ethnomedical records. The present review reports the isolation, occurrence, phytochemistry, biological properties, therapeutic potential and structure–activity relationship of Euphorbia flavonoids for the period covering 2000–2020, while identifying potential areas for future studies aimed at development of new therapeutic agents from these plants. The findings suggest that the extracts and isolated flavonoids possess anticancer, antiproliferative, antimalarial, antibacterial, anti-venom, anti-inflammatory, anti-hepatitis and antioxidant properties and have different mechanisms of action against cancer cells. Of the investigated species, over 80 different types of flavonoids have been isolated to date. Most of the isolated flavonoids were flavonols and comprised simple O-substitution patterns, C-methylation and prenylation. Others had a glycoside, glycosidic linkages and a carbohydrate attached at either C-3 or C-7, and were designated as d-glucose, l-rhamnose or glucorhamnose. The structure–activity relationship studies showed that methylation of the hydroxyl groups on C-3 or C-7 reduces the activities while glycosylation loses the activity and that the parent skeletal structure is essential in retaining the activity. These constituents can therefore offer potential alternative scaffolds towards development of new Euphorbia-based therapeutic agents.

scholarly journals The Inhibitory Effects of Plant Derivate Polyphenols on the Main Protease of SARS Coronavirus 2 and Their Structure–Activity Relationship

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1924
Author(s):  
Thi Thanh Hanh Nguyen ◽  
Jong-Hyun Jung ◽  
Min-Kyu Kim ◽  
Sangyong Lim ◽  
Jae-Myoung Choi ◽  
...  
Keyword(s):  
Structure Activity Relationship ◽  
Garlic Extract ◽  
Activity Relationship ◽  
Hydroxyl Group ◽  
Inhibitory Effects ◽  
Structure Activity ◽  
Main Protease ◽  
Ic50 Values ◽  
Km Value ◽  
Novel Coronavirus

The main protease (Mpro) is a major protease having an important role in viral replication of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the novel coronavirus that caused the pandemic of 2020. Here, active Mpro was obtained as a 34.5 kDa protein by overexpression in E. coli BL21 (DE3). The optimal pH and temperature of Mpro were 7.5 and 37 °C, respectively. Mpro displayed a Km value of 16 μM with Dabcyl-KTSAVLQ↓SGFRKME-Edans. Black garlic extract and 49 polyphenols were studied for their inhibitory effects on purified Mpro. The IC50 values were 137 μg/mL for black garlic extract and 9–197 μM for 15 polyphenols. The mixtures of tannic acid with puerarin, daidzein, and/or myricetin enhanced the inhibitory effects on Mpro. The structure–activity relationship of these polyphenols revealed that the hydroxyl group in C3′, C4′, C5′ in the B-ring, C3 in the C-ring, C7 in A-ring, the double bond between C2 and C3 in the C-ring, and glycosylation at C8 in the A-ring contributed to inhibitory effects of flavonoids on Mpro.

QUANTITATIVE STRUCTURE ACTIVITY RELATIONSHIP MODELING FOR PREDICTION OF PYRIDINE SUBSTITUTED ANALOGUES WITH K-NEAREST NEIGHBOR STUDIES

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (10) ◽  
pp. 16-22
Author(s):  
M. C. Sharma ◽  
◽  
D.V. Kohli
Keyword(s):  
Correlation Coefficient ◽  
Quantitative Relationship ◽  
Quantitative Structure Activity Relationship ◽  
Structure Activity Relationship ◽  
Field Analysis ◽  
Activity Relationship ◽  
Quantitative Structure ◽  
Angiotensin Ii Receptor ◽  
K Nearest Neighbor ◽  
Structure Activity

A quantitative structure activity relationship study was performed on a series of imidazo[4,5-b]pyridine substituted compounds as angiotensin II receptor antagonists for establishing quantitative relationship between activity and their physicochemical properties. The best quantitative structure activity relationship model was generated with correlation coefficient of 0.8318, cross validated correlation coefficient of 0.7142 and r2 for external test set 0.7965. Molecular field analysis was used to construct the best 3D-QSAR model using PLS method, showing good correlative and predictive capabilities in terms of q2 = 0.7264 and pred_r2 = 0.8164. These results will be useful for the design of new antihypertensive molecules.

scholarly journals Antioxidant Activity of 1’-Hydroxyethylnaphthazarins and their Derivatives

2017 ◽  
Vol 12 (12) ◽  
pp. 1934578X1701201
Author(s):  
Natalia K. Utkina ◽  
Natalia D. Pokhilo
Keyword(s):  
Antioxidant Activity ◽  
Radical Cation ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Hydroxyl Group ◽  
Side Chains ◽  
Scavenging Activity ◽  
Structure Activity

The ABTS•+ radical cation scavenging activity of known (2-5, 9, 10) and new (6-8) 1’-hydroxyethylnaphthazarins and their products of esterification and etherification was evaluated and a structure-activity relationship was studied. It was shown, that the structure of side chains does not affect the radical scavenging activity of 1’-hydroxyethylnaphthazarins and their derivatives. The presence of methoxyl groups on the naphthazarin core slightly enhanced the antioxidant activity of compounds compared with compounds without methoxyl groups. The presence of the additional hydroxyl group on the naphthazarin moiety of isonorlomazarin (5) and its derivative (6) is essential for the activity.

scholarly journals SYNTHESIS, CHARACTERIZATION, QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIP, DOCKING, ANTIBACTERIAL ACTIVITY, AND BRINE SHRIMP LETHAL STUDIES ON L-PHENYLALANINE SCHIFF BASES

2016 ◽  
Vol 9 (9) ◽  
pp. 203
Author(s):  
Easwaramoorthi Deivanayagam ◽  
Jayaprakash R ◽  
Aroj Kumar Sha ◽  
Hemalatha S
Keyword(s):  
Antibacterial Activity ◽  
Schiff Base ◽  
Schiff Bases ◽  
Brine Shrimp ◽  
Quantitative Structure Activity Relationship ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Hydroxyl Group ◽  
Quantitative Structure ◽  
Structure Activity

ABSTRACTObjective: Aim of this work is to synthesize and characterization of the hydroxyl group the hydroxyl group substituted L-phenylalanine Schiff basesto compare their predicted quantitative structure-activity relationship (QSAR) and molecular docking against Escherichia coli protein ZipA (1s1j)outcomes with the antibacterial activity and brine shrimp lethal assay (BSLA) results.Methods: The Schiff bases of L-Phenylalanine were synthesized by the simple condensation reaction using methanol, water in 2:1 ratio at reflux andwere characterized by spectral techniques. QSAR parameters of the Schiff bases were predicted using java-based online and offline tools. Moleculardocking carried through online mcule server and CLC Drug Discovery Workbench 3. Antibacterial activity and toxicity studies were conducted usingbroth dilution and brine shrimp lethal assay methods, respectively.Results: The Schiff bases fulfilled the QSAR drug-likeness parameters and showed the docking score between −6.8 and −6.0 Kcal/mol which arehigher than amoxilicillin and gentamicin like standard drugs. They also possess good inhibition for urinary tract infection causing E. coli bacteria,and minimum inhibitory concentrations (MIC) exists between 3.25 and 5.25 μg/ml. The brine shrimp lethal concentration for 50% mortality [LC50])between 58.73 and 135.6 μg/ml.Conclusion: Para, meta and 2,4 hydroxyl substituted Schiff bases exhibited good inhibition against Gram-negative E. coli bacteria at low concentrationand the MIC exists below the LC50 value. The Schiff base showed high drug score, high docking score, and low toxicity than other Schiff base. Dockingscore, high inhibition, low clogP, low MICKeywords: L-phenylalanine, Schiff base, Quantitative structure-activity relationship, Docking, Antibacterial, Lethal concentration for 50% mortality.

scholarly journals Aromatic Hydroxyl Group Plays a Critical Role in Antibacterial Activity of the Curcumin Analogues

2012 ◽  
Vol 7 (1) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Mi Kyoung Kim ◽  
Jun Cheol Park ◽  
Youhoon Chong
Keyword(s):  
Antibacterial Activity ◽  
Critical Role ◽  
Antibacterial Activities ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Hydroxyl Group ◽  
Curcumin Analogues ◽  
Structure Activity ◽  
Relationship Study

The aim of this study was to investigate the role of the aromatic substituents of the curcumin scaffold on the antibacterial activity of the resulting curcumin analogues. Six curcumin analogues with different aromatic substituents were prepared and their antibacterial activities were evaluated against two Gram-positive and four Gram-negative bacteria. The structure-activity relationship study demonstrated that antibacterial activity of the curcumin analogues was critically dependent upon the aromatic hydroxyl group. Thus, hydroxycurcumin with an additional aromatic hydroxyl group on the curcumin scaffold showed antibacterial activity against all six pathogens tested and it remained effective even against ampicillin-resistant Enterobacter cloacae. Along with the previously reported antioxidative effect, the broad-spectrum antibacterial activity of the hydroxycurcumin warrants further investigation of its biological activity as well as extensive structure-activity relationship study of the curcumin analogues with various aromatic substituents.

scholarly journals 2D-QSAR and 3D-QSAR Analyses for EGFR Inhibitors

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Manman Zhao ◽  
Lin Wang ◽  
Linfeng Zheng ◽  
Mengying Zhang ◽  
Chun Qiu ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
3D Qsar ◽  
Qsar Model ◽  
Quantitative Structure Activity Relationship ◽  
Structure Activity Relationship ◽  
Egfr Inhibitors ◽  
Activity Relationship ◽  
Quantitative Structure ◽  
2D Qsar ◽  
Structure Activity

Epidermal growth factor receptor (EGFR) is an important target for cancer therapy. In this study, EGFR inhibitors were investigated to build a two-dimensional quantitative structure-activity relationship (2D-QSAR) model and a three-dimensional quantitative structure-activity relationship (3D-QSAR) model. In the 2D-QSAR model, the support vector machine (SVM) classifier combined with the feature selection method was applied to predict whether a compound was an EGFR inhibitor. As a result, the prediction accuracy of the 2D-QSAR model was 98.99% by using tenfold cross-validation test and 97.67% by using independent set test. Then, in the 3D-QSAR model, the model with q2=0.565 (cross-validated correlation coefficient) and r2=0.888 (non-cross-validated correlation coefficient) was built to predict the activity of EGFR inhibitors. The mean absolute error (MAE) of the training set and test set was 0.308 log units and 0.526 log units, respectively. In addition, molecular docking was also employed to investigate the interaction between EGFR inhibitors and EGFR.

Antioxidant properties of phenolic Schiff bases: structure–activity relationship and mechanism of action

2013 ◽  
Vol 27 (11) ◽  
pp. 951-964 ◽  
Author(s):  
El Hassane Anouar ◽  
Salwa Raweh ◽  
Imene Bayach ◽  
Muhammad Taha ◽  
Mohd Syukri Baharudin ◽  
...  
Keyword(s):  
Schiff Bases ◽  
Mechanism Of Action ◽  
Antioxidant Properties ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Structure Activity

3D-QSAR and Molecular Docking Studies on Design Anti-Prostate Cancer Curcumin Analogues

2020 ◽  
Vol 16 (3) ◽  
pp. 245-256 ◽  
Author(s):  
Xi Meng ◽  
Lianhua Cui ◽  
Fucheng Song ◽  
Mingyuan Luan ◽  
Junjie Ji ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Biological Activity ◽  
Molecular Docking ◽  
Correlation Coefficient ◽  
Structure Activity Relationship ◽  
Docking Studies ◽  
Activity Relationship ◽  
Molecular Docking Studies ◽  
Curcumin Analogs ◽  
Structure Activity

Background: Prostate cancer is one of the most common tumors in the world and the fifth leading cause of male cancer death. Although the treatment of localized androgen-dependent prostate cancer has been successful, the efficacy of androgen-independent metastatic disease is limited. Curcumin, a natural product, has been found to inhibit the proliferation of prostate cancer cells. Objective: To design curcumin analogs with higher biological activity and lower toxicity and side effects for the treatment of prostate cancer. Methods: In this study, the three dimensional-quantitative structure activity relationship (3DQSAR) and molecular docking studies were performed on 34 curcumin analogs as anti-prostate cancer compounds. We introduced OSIRIS Property Explorer to predict drug-related properties of newly designed compounds. Results: The optimum CoMSIA model exhibited statistically significant results: the cross-validated correlation coefficient q2 is 0.540 and non-cross-validated R2 value is 0.984. The external predictive correlation coefficient Rext 2 is 0.792. The information of structure-activity relationship can be obtained from the CoMSIA contour maps. In addition, the molecular docking study of the compounds for 3ZK6 as the protein target revealed important interactions between active compounds and amino acids. Conclusion: Compound 28i may be a new type of anti-prostate cancer drug with higher biological activity and more promising development.

Sign in / Sign up

Export Citation Format

Share Document