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891.
Asim Najmi Sadique A. Javed Mohammed Al Bratty Hassan A. Alhazmi 《Molecules (Basel, Switzerland)》2022,27(2)
Natural products represents an important source of new lead compounds in drug discovery research. Several drugs currently used as therapeutic agents have been developed from natural sources; plant sources are specifically important. In the past few decades, pharmaceutical companies demonstrated insignificant attention towards natural product drug discovery, mainly due to its intrinsic complexity. Recently, technological advancements greatly helped to address the challenges and resulted in the revived scientific interest in drug discovery from natural sources. This review provides a comprehensive overview of various approaches used in the selection, authentication, extraction/isolation, biological screening, and analogue development through the application of modern drug-development principles of plant-based natural products. Main focus is given to the bioactivity-guided fractionation approach along with associated challenges and major advancements. A brief outline of historical development in natural product drug discovery and a snapshot of the prominent natural drugs developed in the last few decades are also presented. The researcher’s opinions indicated that an integrated interdisciplinary approach utilizing technological advances is necessary for the successful development of natural products. These involve the application of efficient selection method, well-designed extraction/isolation procedure, advanced structure elucidation techniques, and bioassays with a high-throughput capacity to establish druggability and patentability of phyto-compounds. A number of modern approaches including molecular modeling, virtual screening, natural product library, and database mining are being used for improving natural product drug discovery research. Renewed scientific interest and recent research trends in natural product drug discovery clearly indicated that natural products will play important role in the future development of new therapeutic drugs and it is also anticipated that efficient application of new approaches will further improve the drug discovery campaign. 相似文献
892.
Rashid Waseem Anas Shamsi Taj Mohammad Md. Imtaiyaz Hassan Syed Naqui Kazim Anis Ahmad Chaudhary Hassan Ahmed Rudayni Mohammed Al-Zharani Faizan Ahmad Asimul Islam 《Molecules (Basel, Switzerland)》2022,27(3)
A sedentary lifestyle or lack of physical activity increases the risk of different diseases, including obesity, diabetes, heart diseases, certain types of cancers, and some neurological diseases. Physical exercise helps improve quality of life and reduces the risk of many diseases. Irisin, a hormone induced by exercise, is a fragmented product of FNDC5 (a cell membrane protein) and acts as a linkage between muscles and other tissues. Over the past decade, it has become clear that irisin is a molecular mimic of exercise and shows various beneficial effects, such as browning of adipocytes, modulation of metabolic processes, regulation of bone metabolism, and functioning of the nervous system. Irisin has a role in carcinogenesis; numerous studies have shown its impact on migration, invasion, and proliferation of cancer cells. The receptor of irisin is not completely known; however, in some tissues it probably acts via a specific class of integrin receptors. Here, we review research from the past decade that has identified irisin as a potential therapeutic agent in the prevention or treatment of various metabolic-related and other diseases. This article delineates structural and biochemical aspects of irisin and provides an insight into the role of irisin in different pathological conditions. 相似文献
893.
Chunmin Yang Afsar Alam Fahad A. Alhumaydhi Mohd Shahnawaz Khan Suliman A. Alsagaby Waleed Al Abdulmonem Md. Imtaiyaz Hassan Anas Shamsi Bilqees Bano Dharmendra Kumar Yadav 《Molecules (Basel, Switzerland)》2022,27(10)
Tyrosine-protein kinase Yes (YES1) belongs to the Tyrosine-protein kinase family and is involved in several biological activities, including cell survival, cell–cell adhesion, cell differentiation, and cytoskeleton remodeling. It is highly expressed in esophageal, lung, and bladder cancers, and thus considered as an attractive drug target for cancer therapy. In this study, we performed a virtual screening of phytoconstituents from the IMPPAT database to identify potential inhibitors of YES1. Initially, the molecules were retrieved on their physicochemical properties following the Lipinski rule of five. Then binding affinities calculation, PAINS filter, ADMET, and PASS analyses followed by an interaction analysis to select safe and clinically better hits. Finally, two compounds, Glabrene and Lupinisoflavone C (LIC), with appreciable affinities and a specific interaction towards the AlphaFold predicted structure of YES1, were identified. Their time-evolution analyses were carried out using an all-atom molecular dynamics (MD) simulation, principal component analysis, and free energy landscapes. Altogether, we propose that Glabrene and LIC can be further explored in clinical settings to develop anticancer therapeutics targeting YES1 kinase. 相似文献
894.
In this work, we define cumulative residual q-Fisher (CRQF) information measures for the survival function (SF) of the underlying random variables as well as for the model parameter. We also propose q-hazard rate (QHR) function via q-logarithmic function as a new extension of hazard rate function. We show that CRQF information measure can be expressed in terms of the QHR function. We define further generalized cumulative residual divergence measures between two SFs. We then examine the cumulative residual q-Fisher information for two well-known mixture models, and the corresponding results reveal some interesting connections between the cumulative residual q-Fisher information and the generalized cumulative residual divergence measures. Further, we define Jensen-cumulative residual (JCR-) measure and a parametric version of the Jensen-cumulative residual Fisher information measure and then discuss their properties and inter-connections. Finally, for illustrative purposes, we examine a real example of image processing and provide some numerical results in terms of the CRQF information measure. 相似文献
895.
The carburizing of titanium (Ti) is accomplished by utilizing
energetic ion pulses of a 1.5 kJ Mather type dense plasma focus (DPF)
device operated in methane discharge. X-ray diffraction (XRD)
analysis confirms the deposition of polycrystalline titanium carbide
(TiC). The samples carburized at lower axial and angular positions
show an improved texture for a typical (200)TiC plane.
The Williamson--Hall method is employed to estimate average crystallite
size and microstrains in the carburized Ti surface. Crystallite size
is found to vary from ~ 50 to 100~nm, depending on the deposition
parameters. Microstrains vary with the sample position and hence ion
flux, and are converted from tensile to compressive by increasing
the flux. The carburizing of Ti is confirmed by two major doublets
extending from 300 to 390~cm-1 and from 560 to 620~cm-1 corresponding to acoustic and optical active modes in Raman
spectra, respectively. Analyses by scanning electron
microscopy/energy dispersive x-ray spectroscopy (SEM/EDS) have
provided qualitative and quantitative profiles of the carburized
surface. The Vickers microhardness of Ti is significantly improved after
carburizing. 相似文献
896.
Mouhammad El Hassan Hassan Hassan Assoum Vaclav Sobolik Jér?me Vétel Kamel Abed-Meraim André Garon Anas Sakout 《Experiments in fluids》2012,52(6):1475-1489
The wall shear stress and the vortex dynamics in a circular impinging jet are investigated experimentally for Re = 1,260 and 2,450. The wall shear stress is obtained at different radial locations from the stagnation point using the polarographic method. The velocity field is given from the time resolved particle image velocimetry (TR‐PIV) technique in both the free jet region and near the wall in the impinging region. The distribution of the momentum thickness is also inspected from the jet exit toward the impinged wall. It is found that the wall shear stress is correlated with the large-scale vortex passing. Both the primary vortices and the secondary structures strongly affect the variation of the wall shear stress. The maximum mean wall shear stress is obtained just upstream from the secondary vortex generation where the primary structures impinge the wall. Spectral analysis and cross-correlations between the wall shear stress fluctuations show that the vortex passing influences the wall shear stress at different locations simultaneously. Analysis of cross-correlations between temporal fluctuations of the wall shear stress and the transverse vorticity brings out the role of different vortical structures on the wall shear stress distribution for the two Reynolds numbers. 相似文献
897.
898.
An efficient one-pot synthesis of tetrahydrobenzo[b]pyran is described. This involved the three-component reaction of aromatic aldehydes, molononitrile, and dimedone in the presence of a catalytic amount of Caro's acid supported on silica gel in ethanol/water under reflux. 相似文献
899.
900.
Hassan Hosseini-Monfared Massomeh Ghorbanloo Christoph Janiak Peter Mayer 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):226-234
Abstract A new type of cascade cyclization was observed in the phosphorylation reaction of (R,R)- or (S,S)-N,N′-bis(salicylidene)cyclohexanediimine with phosphoryltrichloride, which resulted in the formation of bis(chlorophosphorylated) decahydro-2,4-di(2-hydroxyphenyl)benzo[d][1,3,6]oxadiazepine with two new stereogenic phosphorus atoms and two new stereogenic carbon atoms in the oxadiazepine ring in the β-position to phosphorus. During the synthesis, the N atom attacks the phosphorodichloridate group with the formation of the P–N bond to give an asymmetric phosphorus atom and an iminium ion. This compound with six stereogenic centers crystallizes in the monoclinic centrosymmetric space group P21/c and the crystal structure together with solution and solid-state MAS 13C and 31P NMR studies reveals a preferential formation of stereoisomers. 相似文献