scholarly journals Alpha-Glucosidase- and Lipase-Inhibitory Phenalenones from a New Species of Pseudolophiostoma Originating from Thailand

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 965 ◽  
Author(s):  
Allan Patrick G. Macabeo ◽  
Luis Agustin E. Pilapil ◽  
Katherine Yasmin M. Garcia ◽  
Mark Tristan J. Quimque ◽  
Chayanard Phukhamsakda ◽  
...  

The alpha-glucosidase- and lipase-inhibitory activities of three phenalenones (1–3) and one phenylpropanoid (4) from the ethyl acetate extracts of a Pseudolophiosptoma sp. are described. They represent the first secondary metabolites reported from the genus Pseudolophiostoma. Scleroderolide (1) and sclerodione (2) exhibited potent α-glucosidase- and porcine-lipase-inhibitory activity during primary screening, with better IC50 values compared to the positive controls, N-deoxynojirimycin and orlistat. In silico techniques were employed to validate the probable biological targets and elucidate the mechanism of actions of phenalenones 1 and 2. Both compounds exhibited strong binding affinities to both alpha-glucosidase and porcine lipase through H-bonding and π–π interactions. Interestingly, favorable in silico ADME (absorption, distribution, metabolism, and excretion) properties such as gastrointestinal absorption were also predicted using software.

2016 ◽  
Author(s):  
◽  
Njabulo Joyfull Gumede

In drug discovery and development projects, metabolism of new chemical entities (NCEs) is a major contributing factor for the withdrawal of drug candidates, a major concern for other chemical industries where chemical-biological interactions are involved. NCEs interact with a target macro-molecule to stimulate a pharmacological or toxic response, known as pharmacodynamics (PD) effect or through the Adsorption, Distribution, Metabolism, and Excretion (ADME) process, triggered when a bio-macromolecule interacts with a therapeutic drug. Therefore, the drug discovery process is important because 75% of diseases known to human kind are not all cured by therapeutics currently available in the market. This is attributed to the lack of knowledge of the function of targets and their therapeutic use in order to design therapeutics that would trigger their pharmacological responses. Accordingly, the focus of this work is to develop cost saving strategies for medicinal chemists involved with drug discovery projects. Therefore, studying the synergy between in silico and in vitro approaches maybe useful in the discovery of novel therapeutic compounds and their biological activities. In this work, in silico methods such as structure-based and ligand-based approaches were used in the design of the pharmacophore model, database screening and flexible docking methods. Specifically, this work is presented by the following case studies: The first involved molecular docking studies to predict the binding modes of catechin enantiomer to human serum albumin (HSA) interaction; the second involved the use of docking methods to predict the binding affinities and enantioselectivity of the interaction of warfarin enantiomers to HSA. the third case study involved a combined computational strategy in order to generate information on a diverse set of steroidal and non-steroidal CYP17A1 inhibitors obtained from literature with known experimental IC50 values. Finally, the fourth case study involved the prediction of the site of metabolisms (SOMs) of probe substrates to Cytochrome P450 metabolic enzymes CYP 3A4, 2D6, and 2C9 making use of P450 module from Schrödinger suite for ADME/Tox prediction. The results of case study I were promising as they were able to provide clues to the factors that drive the synergy between experimental kinetic parameters and computational thermodynamics parameters to explain the interaction between drug enantiomers and thetarget protein. These parameters were correlated/converted and used to estimate the pseudo enantioselectivity of catechin enantiomer to HSA. This approach of combining docking methodology with docking post-processing methods such as MM-GBSA proved to be vital in estimating the correct pseudo binding affinities of a protein-ligand complexes. The enantioselectivity for enantiomers of catechin to HSA were 1,60 and 1,25 for site I and site II respectively. The results of case study II validates and verifies the preparation of ligands and accounting for tautomers at physiological pH, as well as conformational changes prior to and during docking with a flexible protein. The log KS = 5.43 and log KR = 5.34 for warfarin enantiomer-HSA interaction and the enantioselectivity (ES = KS/KR) of 1.23 were close to the experimental results and hence referred to as experimental-like affinity constants which validated and verified their applicability to predict protein-ligand binding affinities. In case study III, a 3D-QSAR pharmacophore model was developed by using 98 known CYP17A1 inhibitors from the literature with known experimental IC50 values. The starting compounds were diverse which included steroidal and non-steroidal inhibitors. The resulting pharmacophore models were trained with 69 molecules and 19 test set ligands. The best pharmacophore models were selected based on the regression coefficient for a best fit model with R2 (ranging from 0.85-0.99) & Q2 (ranging from 0.80-0.99) for both the training and test sets respectively, using Partial Least Squares (PLS) regression. On the other hand, the best pharmacophore model selected was further used for a database screening of novel inhibitors and the prediction of their CYP17A1 inhibition. The hits obtained from the database searches were further subjected to a virtual screening workflow docked to CYP17A1 enzyme in order to predict the binding mode and their binding affinities. The resulting poses from the virtual screening workflow were subjected to Induced Fit Docking workflow to account for protein flexibility during docking. The resulting docking poses were examined and ranked ordered according to the docking scores (a measure of affinity). Finally, the resulting hits designed from an updated model from case study III were further synthesized in an external organic chemistry laboratory and the synthetic protocols as well as spectroscopic data for structure elucidation forms part of the provisional patent specification. A provisional patent specification has been filed (RSA Pat. Appln. 2015/ 07849). The case studies performed in this thesis have enabled the discovery of non-steroidal CYP17A1 inhibitors.


2021 ◽  
Vol 7 (10) ◽  
pp. 876
Author(s):  
Geum Seok Jeong ◽  
Prima F. Hillman ◽  
Myung-Gyun Kang ◽  
Sungbo Hwang ◽  
Jong-Eun Park ◽  
...  

Using 126 endogenous lichen fungus (ELF) extracts, inhibitory activities against monoamine oxidases (MAOs) and cholinesterases (ChEs) were evaluated. Among them, extract ELF29 of the endogenous fungus Diaporthe mahothocarpus of the lichen Cladonia symphycarpia showed the highest inhibitory activity against hMAO-A. Compounds alternariol (AT), 5′-hydroxy-alternariol (HAT), and mycoepoxydiene (MED), isolated from the extract, had potent inhibitory activities against hMAO-A with IC50 values of 0.020, 0.31, and 8.68 µM, respectively. AT, HAT, and MED are reversible competitive inhibitors of hMAO-A with Ki values of 0.0075, 0.116, and 3.76 µM, respectively. The molecular docking studies suggested that AT, HAT, and MED had higher binding affinities for hMAO-A (−9.1, −6.9, and −5.6 kcal/mol, respectively) than for hMAO-B (−6.3, −5.2, and −3.7 kcal/mol, respectively). The relative tight binding might result from a hydrogen bond interaction of the three compounds with a Tyr444 residue in hMAO-A, whereas no hydrogen bond interaction was proposed in hMAO-B. In silico pharmacokinetics, the three compounds showed high gastrointestinal absorption without violating Lipinski’s five rules, but only MED showed high probability to cross the blood–brain barrier. These results suggest that AT, HAT, and MED are candidates for treating neuropsychiatric disorders, such as depression and cardiovascular disease.


Antioxidants ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 162 ◽  
Author(s):  
Mariarosaria Leporini ◽  
Monica Rosa Loizzo ◽  
Rosa Tundis ◽  
Chiara La Torre ◽  
Alessia Fazio ◽  
...  

N-Eicosapentaenoyl vanillylamine (EPVA) and N-docosahexaenoyl vanillylamine (DHVA), derived from n-3 polyunsaturated eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively, were studied for their potential antioxidant and carbohydrate-hydrolysing enzyme inhibitory activities together with capsaicin and the corresponding n-3 polyunsaturated fatty acids (PUFAs). The antioxidant potential was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay, β-carotene bleaching test, and ferric reducing ability power (FRAP). In the ABTS assay the following trend of potency could be observed EPVA > DHVA ≥ capsaicin. In addition, except for the FRAP test, all samples showed a greater activity than the positive controls used as reference compounds in the antioxidant assays. Both EPVA and DHVA showed half maximal inhibitory concentration (IC50) values much lower than acarbose, which was used as the reference drug in the carbohydrate-hydrolysing enzyme inhibitory activity assays. It is interesting to note that structural changes in capsaicin derivatives had higher impacts on α-glucosidase than on α-amylase inhibition. Taken together, our data suggest that both EPVA and DHVA, which are not limited in compliance-related considerations with respect to capsaicin, due to absence of pungency, could be proposed as functional ingredients for the development of products for the management of type II diabetes and border-line hyperglycaemic patients.


2011 ◽  
Vol 14 (2) ◽  
pp. 36-42
Author(s):  
Nhi Thi Y Nguyen ◽  
Qui Kim Tran ◽  
Quan Le Tran

Two new limonoids, named nimbandiol A (1) and azadirachtolid E (2) were isolated from the leaves of Azadirachta indica, along with deoxyazadirachtolid (3), a known compound. Their structures were determined by spectroscopic methods and compared with literatures. Three compounds (1-3) showed moderate a-glucosidase inhibitory activities against Saccharomyces cerevisiae a-glucosidase with IC50 values of 38.7 mM, 85.76 mM and 48.24 mM, respectively.


Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1149
Author(s):  
Ninon G. E. R. Etsassala ◽  
Jelili A. Badmus ◽  
Jeanine L. Marnewick ◽  
Emmanuel I. Iwuoha ◽  
Felix Nchu ◽  
...  

Diabetes mellitus (DM) is one of the most dangerous metabolic diseases with a high rate of mortality worldwide. It is well known that insulin resistance and deficiency in insulin production from pancreatic β-cells are the main characteristics of DM. Due to the detrimental side effects of the current treatment, there is a considerable need to develop new effective antidiabetic drugs, especially alpha-glucosidase and alpha-amylase inhibitors with lesser adverse effects. These inhibitors are known to be directly involved in the delay of carbohydrate digestion, resulting in a reduction of glucose absorption rate and, consequently, reducing the postprandial rise of plasma glucose, which can reduce the risk of long-term diabetes complications. Furthermore, natural products are well-known sources for the discovery of new bioactive compounds that can serve as scaffolds for drug discovery, including that of new antidiabetic drugs. The phytochemical investigation of Salvia aurita collected from Hogobach Pass, Eastern Cape Province, South Africa (SA), yielded four known abietane diterpenes namely carnosol (1), rosmanol (2), 7-methoxyrosmanol (3), 12-methoxycarnosic acid (4), and one flavonoid named 4,7-dimethylapigenin (5). Structural characterization of these isolated compounds was conducted using 1 and 2D NMR, in comparison with reported spectroscopic data. These compounds are reported for the first time from S. aurita. The biological evaluation of the isolated compound against alpha-glucosidase exhibited strong inhibitory activities for 3 and 2 with the half maximal inhibitory concentration (IC50) values of 4.2 ± 0.7 and 16.4 ± 1.1 µg/mL respectively, while 4 and 1 demonstrated strong alpha-amylase inhibitory activity amongst the isolated compounds with IC50 values of 16.2 ± 0.3 and 19.8 ± 1.4 µg/mL. Molecular docking analysis confirms the strong inhibitory activity of 3 against alpha-glucosidase. Additionally, excellent antioxidant capacities were displayed by 2, 1, and 3, respectively, with oxygen radical absorbance capacity (ORAC) (25.79 ± 0.01; 23.96 ± 0.01; 23.94 ± 0.02) mM Trolox equivalent (TE)/g; 1 and 2 as ferric-ion reducing antioxidant power (FRAP) (3.92 ± 0.002; 1.52 ± 0.002) mM ascorbic acid equivalent (AAE)/g; 5 and 2 as Trolox equivalent absorbance capacity (TEAC) (3.19 ± 0.003; 2.06 ± 0.003) mM TE/g. The methanolic extract of S. aurita is a rich source of abietane diterpenes with excellent antioxidant and antidiabetic activities that can be useful to modulate oxidative stress and might possibly be excellent candidates for the management of diabetes. This is the first scientific report on the phytochemical isolation and biological evaluation of the alpha-glucosidase and alpha-amylase inhibitory activities of Salvia aurita.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2981
Author(s):  
Erman Salih Istifli

The aim of this study was to investigate the chemical composition, antioxidant and enzyme inhibitory activities of methanol (MeOH) extracts from Onosma bourgaei (Boiss.) and O. trachytricha (Boiss.). In addition, the interactions between phytochemicals found in extracts in high amounts and the target enzymes in question were revealed at the molecular scale by performing in silico molecular docking simulations. While the total amount of flavonoid compounds was higher in O. bourgaei, O. trachytricha was richer in phenolics. Chromatographic analysis showed that the major compounds of the extracts were luteolin 7-glucoside, apigenin 7-glucoside and rosmarinic acid. With the exception of the ferrous ion chelating assay, O. trachytricha exhibited higher antioxidant activity than O. bourgaei. O. bourgaei exhibited also slightly higher activity on digestive enzymes. The inhibitory activities of the Onosma species on tyrosinase were almost equal. In addition, the inhibitory activities of the extracts on acetylcholinesterase (AChE) were stronger than the activity on butyrylcholinesterase (BChE). Molecular docking simulations revealed that luteolin 7-glucoside and apigenin 7-glucoside have particularly strong binding affinities against ChEs, tyrosinase, α-amylase and α-glucosidase when compared with co-crystallized inhibitors. Therefore, it was concluded that the compounds in question could act as effective inhibitors on cholinesterases, tyrosinase and digestive enzymes.


2019 ◽  
Vol 16 (3) ◽  
pp. 290-296 ◽  
Author(s):  
Dikdik Kurnia ◽  
Eti Apriyanti ◽  
Cut Soraya ◽  
Mieke H. Satari

Background: A significant number of antibiotics are known to inhibit peptidoglycan synthesis in the cross-linking stage, while the drug fosfomycin is the only one known to inhibit MurA. Escalated antibiotic resistance has had an impact on the efficacy of fosfomycin, thus demanding the discovery of suitable substitutes with improved potential for MurA inhibition. The aim of this work is to isolate antibacterial compounds from Sarang Semut (Myrmecodia pendans) and to evaluate their antibacterial activity against pathogenic oral bacteria of Enterococcus faecalis ATCC 29212 and inhibitory activity against MurA enzyme. Methods: The antibacterial compounds from Sarang Semut were isolated by a bioactivity-guided separation method with various solvents and combination of column chromatography on normal and reverse phases. The compounds with concentrations of 1000 and 5000 ppm were assessed against E. faecalis ATCC 29212 by agar well diffusion method, with chlorhexidine and fosfomycin being used as positive controls. Results: Two antibacterial compounds isolated from Sarang Semut were identified as two new flavonoids derivates of 1 (10 mg) and 2 (4 mg). Both compounds were tested for antibacterial activities against E. faecalis. MIC values of compounds 1 and 2 were 8.15 and 8.05 mm at 1000 ppm and 8.62 and 8.55 mm at 5000 ppm, respectively. MBC values were 156 and 625 ppm for 1 and 625 and 2500 ppm for 2, respectively. In an inhibitory murA enzyme activity assay, compounds 1 and 2 were shown to inhibit the enzyme activity by IC50 values of 21.7 and 151.3 ppm. Conclusion: The study demonstrated that ethyl acetate fraction of Sarang Semut contained antibacterial flavonoids as active constituents that showed activity against E. faecalis. These results showed the plant’s potential in herbal medicine and the development of new antibacterial agent for pathogenic dental caries.


2019 ◽  
Vol 16 (6) ◽  
pp. 474-477 ◽  
Author(s):  
Pham Van Khang ◽  
Nguyen Thi Hien Lan ◽  
Le Quang Truong ◽  
Mai Thi Minh Chau ◽  
Mai Xuan Truong ◽  
...  

In this report, two new steroidal glycosides were isolated and determined from n-butanol fraction of A.asphodeloides. The structures were confirmed in comparison with the spectral data of known compounds by using different spectroscopic analysis approaches including 1D & 2D-NMR techniques and HRMS. The anti-proliferation screening against cancer cell lines A549 and HeLa indicated that compound 1 exhibited good inhibitory activities with IC50 values of 0.79 and 0.55 µg/mL, respectively.


2019 ◽  
Vol 16 (3) ◽  
pp. 256-272
Author(s):  
Uzma Salar ◽  
Khalid Mohammed Khan ◽  
Syeda Abida Ejaz ◽  
Abdul Hameed ◽  
Mariya al-Rashida ◽  
...  

Background: Alkaline Phosphatase (AP) is a physiologically important metalloenzyme that belongs to a large family of ectonucleotidase enzymes. Over-expression of tissue non-specific alkaline phosphatase has been linked with ectopic calcification including vascular and aortic calcification. In Vascular Smooth Muscles Cells (VSMCs), the high level of Reactive Oxygen Species (ROS) resulted in the up-regulation of TNAP. Accordingly, there is a need to identify highly potent and selective inhibitors of APs for treatment of disorders related to hyper activity of APs. </P><P> Methods: Herein, a series of coumarinyl alkyl/aryl sulfonates (1-40) with known Reactive Oxygen Species (ROS) inhibition activity, was evaluated for alkaline phosphatase inhibition against human Tissue Non-specific Alkaline Phosphatase (hTNAP) and Intestinal Alkaline Phosphatase (hIAP). </P><P> Results: With the exception of only two compounds, all other compounds in the series exhibited excellent AP inhibition. For hIAP and hTNAP inhibition, IC50 values were observed in the range 0.62-23.5 &#181;M, and 0.51-21.5 &#181;M, respectively. Levamisole (IC50 = 20.21 &#177; 1.9 &#181;M) and Lphenylalanine (IC50 = 100.1 &#177; 3.15 &#181;M) were used as standards for hIAP and hTNAP inhibitory activities, respectively. 4-Substituted coumarinyl sulfonate derivative 23 (IC50 = 0.62 &#177; 0.02 &#181;M) was found to be the most potent hIAP inhibitor. Another 4-substituted coumarinyl sulfonate derivative 16 (IC50 = 0.51 &#177; 0.03 &#181;M) was found to be the most active hTNAP inhibitor. Some of the compounds were also found to be highly selective inhibitors of APs. Detailed Structure-Activity Relationship (SAR) and Structure-Selectivity Relationship (SSR) analysis were carried out to identify structural elements necessary for efficient and selective AP inhibition. Molecular modeling and docking studies were carried out to rationalize the most probable binding site interactions of the inhibitors with the AP enzymes. In order to evaluate drug-likeness of compounds, in silico ADMETox evaluation was carried out, most of the compounds were found to have favorable ADME profiles with good predicted oral bioavailability. X-ray crystal structures of compounds 38 and 39 were also determined. </P><P> Conclusion: Compounds from this series may serve as lead candidates for future research in order to design even more potent, and selective inhibitors of APs.


2020 ◽  
Vol 17 (11) ◽  
pp. 1330-1341
Author(s):  
Yan Zhang ◽  
Niefang Yu

Background: Fibroblast growth factors (FGFs) and their high affinity receptors (FGFRs) play a major role in cell proliferation, differentiation, migration, and apoptosis. Aberrant FGFR signaling pathway might accelerate development in a broad panel of malignant solid tumors. However, the full application of most existing small molecule FGFR inhibitors has become a challenge due to the potential target mutation. Hence, it has attracted a great deal of attention from both academic and industrial fields for hunting for novel FGFR inhibitors with potent inhibitory activities and high selectivity. Objective: Novel 5-amino-1H-pyrazole-1-carbonyl derivatives were designed, synthesized, and evaluated as FGFR inhibitors. Methods: A series of 5-amino-1H-pyrazole-1-carbonyl derivatives were established by a condensation of the suitable formyl acetonitrile derivatives with either hydrazine or hydrazide derivatives in the presence of anhydrous ethanol or toluene. The inhibitory activities of the target compounds were screened against the FGFRs and two representative cancer cell lines. Tests were carried out to observe the inhibition of 8e against FGFR phosphorylation and downstream signal phosphorylation in human gastric cancer cell lines (SNU-16). The molecular docking of all the compounds were performed using Molecular Operating Environment in order to evaluate their binding abilities with the corresponding protein kinase. Results: A series of 5-amino-1H-pyrazole-1-carbonyl derivatives have been designed and synthesized, screened for their inhibitory activities against FGFRs and cancer cell lines. Most of the target compounds showed moderate to good anti-proliferate activities against the tested enzymes and cell lines. The most promising compounds 8e suppressed FGFR1-3 with IC50 values of 56.4, 35.2, 95.5 nM, and potently inhibited the SNU-16 and MCF-7 cancer cells with IC50 values of 0.71 1.26 μM, respectively. And 8e inhibited the growth of cancer cells containing FGFR activated by multiple mechanisms. In addition, the binding interactions were quite similar in the molecular models between generated compounds and Debio-1347 with the FGFR1. Conclusion: According to the experimental findings, 5-amino-1H-pyrazole-1-carbonyl might serve as a promising template of an FGFR inhibitor.


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