scholarly journals Screening of Inhibitory Effects of Polyphenols on Akt-Phosphorylation in Endothelial Cells and Determination of Structure-Activity Features

Biomolecules ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 219 ◽  
Author(s):  
Stoyan Dirimanov ◽  
Petra Högger
Keyword(s):  
Endothelial Cells ◽  
Structural Characteristics ◽  
Structural Features ◽  
Cardiovascular Complications ◽  
Cellular Level ◽  
Inhibitory Effects ◽  
Akt Phosphorylation ◽  
Beneficial Effects ◽  
Structure Activity ◽  
Molecular Mode

Polyphenols exert beneficial effects in type 2 diabetes mellitus (T2DM). However, their mechanism of action remains largely unknown. Endothelial Akt-kinase plays a key role in the pathogenesis of cardiovascular complications in T2DM and therefore the modulation of its activity is of interest. This work aimed to characterize effects of structurally different polyphenols on Akt-phosphorylation (pAkt) in endothelial cells (Ea.hy926) and to describe structure-activity features. A comprehensive screening via ELISA quantified the effects of 44 polyphenols (10 µM) on pAkt Ser473. The most pronounced inhibitors were luteolin (44 ± 18%), quercetin (36 ± 8%), urolithin A (35 ± 12%), apigenin, fisetin, and resveratrol; (p < 0.01). The results were confirmed by Western blotting and complemented with corresponding experiments in HUVEC cells. A strong positive and statistically significant correlation between the mean inhibitory effects of the tested polyphenols on both Akt-residues Ser473 and Thr308 (r = 0.9478, p = 0.0003) was determined by immunoblotting. Interestingly, the structural characteristics favoring pAkt inhibition partially differed from structural features enhancing the compounds’ antioxidant activity. The present study is the first to quantitatively compare the influence of polyphenols from nine different structural subclasses on pAkt in endothelial cells. These effects might be advantageous in certain T2DM-complications involving over-activation of the Akt-pathway. The suggested molecular mode of action of polyphenols involving Akt-inhibition contributes to understanding their effects on the cellular level.

Structure-activity studies on open-chain analogues of nucleosides: Inhibition of S-adenosyl-L-homocysteine hydrolase and antiviral activity 1. Neutral open-chain analogues

1985 ◽  
Vol 50 (1) ◽  
pp. 245-261 ◽  
Author(s):  
Antonín Holý ◽  
Ivan Votruba ◽  
Erik De Clercq
Keyword(s):  
Antiviral Activity ◽  
Alkyl Chain ◽  
Structural Features ◽  
Inhibitory Effects ◽  
Open Chain ◽  
Structure Activity ◽  
Vicinal Diol ◽  
Alkyl Derivatives ◽  
Vesicular Stomatitis ◽  
Derivatives Of

Over 70 alkyl derivatives of purine bases were examined for their inhibitory effects toward rat liver S-adenosyl-L-homocysteine hydrolase and their antiviral activity. The following structural features must be fulfilled by an inhibitor of SAH-hydrolase: an intact adenine moiety, an alkyl chain bound at the 9-position and bearing a vicinal diol at the 2',3'-position, with 2S configuration. An additional substitution at the 3-position lowers or annihilates the inhibitory activity. The enzyme inhibition is reversible. Some of the compounds are substrates of adenosine aminohydrolase. All inhibitors of SAH-hydrolase exhibit antiviral activity, e.g. against vesicular stomatitis virus and vaccinia virus in cell culture, and this antiviral correlates with the inhibition of SAH-hydrolase.

HAZARD: An Expert System for Risk Assessment of Environmental Chemicals

1987 ◽  
Vol 26 (01) ◽  
pp. 13-23 ◽  
Author(s):  
H. W. Gottinger
Keyword(s):  
Expert System ◽  
Structural Information ◽  
Chemical Carcinogenesis ◽  
Structural Features ◽  
Environmental Chemicals ◽  
Chemical Carcinogens ◽  
Carcinogenic Activity ◽  
Current State ◽  
Structure Activity ◽  
Carcinogenic Potential

AbstractThe purpose of this paper is to report on an expert system in design that screens for potential hazards from environmental chemicals on the basis of structure-activity relationships in the study of chemical carcinogenesis, particularly with respect to analyzing the current state of known structural information about chemical carcinogens and predicting the possible carcinogenicity of untested chemicals. The structure-activity tree serves as an index of known chemical structure features associated with carcinogenic activity. The basic units of the tree are the principal recognized classes of chemical carcinogens that are subdivided into subclasses known as nodes according to specific structural features that may reflect differences in carcinogenic potential among chemicals in the class. An analysis of a computerized data base of known carcinogens (knowledge base) is proposed using the structure-activity tree in order to test the validity of the tree as a classification scheme (inference engine).

Targeting AMPK in Diabetes and Diabetic Complications: Energy Homeostasis, Autophagy and Mitochondrial Health

2019 ◽  
Vol 26 (27) ◽  
pp. 5207-5229 ◽  
Author(s):  
Y.V. Madhavi ◽  
Nikhil Gaikwad ◽  
Veera Ganesh Yerra ◽  
Anil Kumar Kalvala ◽  
Srinivas Nanduri ◽  
...  
Keyword(s):  
Diabetic Complications ◽  
Energy Homeostasis ◽  
Cardiovascular Complications ◽  
Living System ◽  
Animal Models Of Disease ◽  
Beneficial Effects ◽  
Inflammatory Processes ◽  
Energy Sensing ◽  
Healthy Functioning ◽  
Models Of Disease

Adenosine 5′-monophosphate activated protein kinase (AMPK) is a key enzymatic protein involved in linking the energy sensing to the metabolic manipulation. It is a serine/threonine kinase activated by several upstream kinases. AMPK is a heterotrimeric protein complex regulated by AMP, ADP, and ATP allosterically. AMPK is ubiquitously expressed in various tissues of the living system such as heart, kidney, liver, brain and skeletal muscles. Thus malfunctioning of AMPK is expected to harbor several human pathologies especially diseases associated with metabolic and mitochondrial dysfunction. AMPK activators including synthetic derivatives and several natural products that have been found to show therapeutic relief in several animal models of disease. AMP, 5-Aminoimidazole-4-carboxamide riboside (AICA riboside) and A769662 are important activators of AMPK which have potential therapeutic importance in diabetes and diabetic complications. AMPK modulation has shown beneficial effects against diabetes, cardiovascular complications and diabetic neuropathy. The major impact of AMPK modulation ensures healthy functioning of mitochondria and energy homeostasis in addition to maintaining a strict check on inflammatory processes, autophagy and apoptosis. Structural studies on AMP and AICAR suggest that the free amino group is imperative for AMPK stimulation. A769662, a non-nucleoside thienopyridone compound which resulted from the lead optimization studies on A-592107 and several other related compound is reported to exhibit a promising effect on diabetes and its complications through activation of AMPK. Subsequent to the discovery of A769662, several thienopyridones, hydroxybiphenyls pyrrolopyridones have been reported as AMPK modulators. The review will explore the structure-function relationships of these analogues and the prospect of targeting AMPK in diabetes and diabetic complications.

Naldemedine: Peripherally Acting Opioid Receptor Antagonist for Treating Opioid-induced Adverse Effects

2020 ◽  
Vol 20 (31) ◽  
pp. 2830-2842
Author(s):  
Masanao Inagaki ◽  
Toshiyuki Kanemasa ◽  
Takaaki Yokota
Keyword(s):  
Adverse Effects ◽  
Adverse Events ◽  
Severe Pain ◽  
Lead Compound ◽  
Inhibitory Effects ◽  
Pharmacokinetic Profiles ◽  
Structure Activity ◽  
The Usa ◽  
Relationship Study ◽  
The Eu

Opioids are widely used for pain management in moderate-to-severe pain. However, opioids are associated with adverse events, such as constipation and emesis/vomiting. To reduce these undesired effects, a structure–activity relationship study of morphinan derivatives was conducted, and a promising lead compound with inhibitory effects on opioid receptors was obtained. Further improvement in the potency and pharmacokinetic profiles of the lead compound led to the discovery of naldemedine, which showed anti-constipation and anti-emetic effects against these adverse events that were induced by morphine without influencing morphine’s analgesic effect. Naldemedine was launched in Japan and the USA in 2017 and in the EU in 2019, for treating opioid-induced constipation.

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.

scholarly journals Structure modification, antialgal, antiplasmodial, and toxic evaluations of a series of new marine-derived 14-membered resorcylic acid lactone derivatives

2021 ◽  
Author(s):  
Wei-Feng Xu ◽  
Na-Na Wu ◽  
Yan-Wei Wu ◽  
Yue-Xuan Qi ◽  
Mei-Yan Wei ◽  
...  
Keyword(s):  
Positive Control ◽  
Structure Modification ◽  
Inhibitory Effects ◽  
Cytotoxicity Assays ◽  
Structure Activity ◽  
Novel Drugs ◽  
Systematic Strategy ◽  
Nmr Techniques ◽  
Acid Lactone ◽  
Drug Leads

AbstractMarine natural products play critical roles in the chemical defense of many marine organisms and are essential, reputable sources of successful drug leads. Sixty-seven 14-membered resorcylic acid lactone derivatives 3–27 and 30–71 of the natural product zeaenol (1) isolated from the marine-derived fungus Cochliobolus lunatus were semisynthesized by chlorination, acylation, esterification, and acetalization in one to three steps. The structures of these new derivatives were established by HRESIMS and NMR techniques. All the compounds (1–71) were evaluated for their antialgal and antiplasmodial activities. Among them, 14 compounds displayed antifouling activities against adhesion of the fouling diatoms. In particular, 9 and 34 exhibited strong and selective inhibitory effects against the diatoms Navicula laevissima and Navicula exigua (EC50 = 6.67 and 8.55 μmol/L), respectively, which were similar in efficacy to those of the positive control SeaNine 211 (EC50 = 2.90 and 9.74 μmol/L). More importantly, 38, 39, and 69–71 showed potent antiplasmodial activities against Plasmodium falciparum with IC50 values ranging from 3.54 to 9.72 μmol/L. Very interestingly, the five antiplasmodial derivatives displayed non-toxicity in the cytotoxicity assays and the zebrafish embryos model, thus, representing potential promising antiplasmodial drug agents. The preliminary structure–activity relationships indicated that biphenyl substituent at C-2, acetonide at positions C-5′ and C-6′, and tri- or tetra-substituted of acyl groups increased the antiplasmodial activity. Therefore, combining evaluation of chemical ecology with pharmacological models will be implemented as a systematic strategy, not only for environmentally friendly antifoulants but also for structurally novel drugs.

scholarly journals Synthesis and Characterization of a Fullerenol Derivative for Potential Biological Applications

2020 ◽  
Vol 4 (1) ◽  
pp. 15
Author(s):  
Eduardo Ravelo-Nieto ◽  
Alvaro Duarte-Ruiz ◽  
Luis H. Reyes ◽  
Juan C. Cruz
Keyword(s):  
Phase Transfer ◽  
Protein A ◽  
Structural Features ◽  
Cellular Level ◽  
Cellulose Membrane ◽  
Cell Penetration ◽  
Covalent Functionalization ◽  
Dialysis Tubing ◽  
Surface Functionality

Several biological barriers are generally responsible for the limited delivery of cargoes at the cellular level. Fullerenols have unique structural features and possess suitable properties for interaction with the cells. This study aimed to synthesize and characterize a fullerenol derivative with desirable characteristics (size, charge, functionality) to develop cell penetration vehicles. Fullerenol was synthesized from fullerene (C60) solubilized in toluene, followed by hydroxylation with hydrogen peroxide and tetra-n-butylammonium hydroxide (TBAH) as a phase transfer catalyst. The obtained product was purified by a Florisil chromatography column (water as the eluent), followed by dialysis (cellulose membrane dialysis tubing) and freeze-drying (yield 66%). Subsequently, a silane coupling agent was conjugated on the fullerenol surface to render free amine functional groups for further covalent functionalization with other molecules. Characterization via UV–VIS, FTIR-ATR, Raman, DLS, and SEM techniques was conducted to evaluate the composition, size, morphology, surface functionality, and structural properties. We are currently working on the conjugation of the potent cell-penetrating agents Buforin II (BUFII) and the Outer Membrane Protein A (OmpA) on the surface of the fullerenol to estimate whether cell penetration and endosome escape are improved concerning conventional polymeric vehicles and our previous developments with iron oxide nanoparticles.

scholarly journals Cytotoxic Agents in the Minor Alkaloid Groups of the Amaryllidaceae

Planta Medica ◽  
2021 ◽  
Author(s):  
Jerald J. Nair ◽  
Johannes van Staden
Keyword(s):  
Cancer Cells ◽  
Cancer Cell Line ◽  
Structural Features ◽  
Biological Properties ◽  
Cytotoxic Agents ◽  
Plant Family ◽  
Structure Activity ◽  
Significant Interest ◽  
Different Types ◽  
Minor Alkaloid

AbstractOver 600 alkaloids have to date been identified in the plant family Amaryllidaceae. These have been arranged into as many as 15 different groups based on their characteristic structural features. The vast majority of studies on the biological properties of Amaryllidaceae alkaloids have probed their anticancer potential. While most efforts have focused on the major alkaloid groups, the volume and diversity afforded by the minor alkaloid groups have promoted their usefulness as targets for cancer cell line screening purposes. This survey is an in-depth review of such activities described for around 90 representatives from 10 minor alkaloid groups of the Amaryllidaceae. These have been evaluated against over 60 cell lines categorized into 18 different types of cancer. The montanine and cripowellin groups were identified as the most potent, with some in the latter demonstrating low nanomolar level antiproliferative activities. Despite their challenging molecular architectures, the minor alkaloid groups have allowed for facile adjustments to be made to their structures, thereby altering the size, geometry, and electronics of the targets available for structure-activity relationship studies. Nevertheless, it was seen with a regular frequency that the parent alkaloids were better cytotoxic agents than the corresponding semisynthetic derivatives. There has also been significant interest in how the minor alkaloid groups manifest their effects in cancer cells. Among the various targets and pathways in which they were seen to mediate, their ability to induce apoptosis in cancer cells is most appealing.

scholarly journals Triterpene Acid and Phenolics from Ancient Apples of Friuli Venezia Giulia as Nutraceutical Ingredients: LC-MS Study and In Vitro Activities

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1109 ◽  
Author(s):  
Stefania Sut ◽  
Gokhan Zengin ◽  
Filippo Maggi ◽  
Mario Malagoli ◽  
Stefano Dall’Acqua
Keyword(s):  
Radical Scavenging ◽  
Reducing Power ◽  
Total Phenolic ◽  
Inhibitory Effects ◽  
Triterpene Acid ◽  
Beneficial Effects ◽  
Triterpene Acids ◽  
Phenolic Constituents ◽  
Friuli Venezia Giulia

Triterpene acid and phenolic constituents from nine ancient varieties of apple (Malus domestica) fruits cultivated in Fanna, Friuli Venezia Giulia region, northeast Italy, were analyzed and compared with four commercial apples (‘Golden Delicious’, ‘Red Delicious’, ‘Granny Smith’ and ‘Royal Gala’). Total phenolic and flavonoid contents were measured by spectrophotometric assays. The quali-quantitative fingerprint of secondary metabolites including triterpene acid was obtained by LC-DAD-(ESI)-MS and LC-(APCI)-MS, respectively. Based on the two LC-MS datasets, multivariate analysis was used to compare the composition of ancient fruit varieties with those of four commercial apples. Significant differences related mainly to the pattern of triterpene acids were found. Pomolic, euscaphyc, maslinic and ursolic acids are the most abundant triterpene in ancient varieties pulps and peels, while ursolic and oleanolic acids were prevalent in the commercial fruits. Also, the content of the phenolic compounds phloretin-2-O-xyloglucoside and quercetin-3-O-arabinoside was greater in ancient apple varieties. The antioxidant (radical scavenging, reducing power, metal chelating and phosphomolybdenum assays) and enzyme inhibitory effects (against cholinesterase, tyrosinase, amylase and glucosidase) of the samples were investigated in vitro. Antioxidant assays showed that the peels were more active than pulps. However, all the samples exhibited similar enzyme inhibitory effects. Ancient Friuli Venezia Giulia apple cultivars can be a source of chlorogenic acid and various triterpene acids, which are known for their potential anti-inflammatory activity and beneficial effects on lipid and glucose metabolism. Our results make these ancient varieties suitable for the development of new nutraceutical ingredients.

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