| 1. |
- Ali, Kiran, et al.
(författare)
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Rapid Identification of Common Secondary Metabolites of Medicinal Herbs Using High-Performance Liquid Chromatography with Evaporative Light Scattering Detector in Extracts
- 2021
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Ingår i: Metabolites. - : MDPI AG. - 2218-1989 .- 2218-1989. ; 11:8
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Tidskriftsartikel (refereegranskat)abstract
- The discovery and identification of novel natural products of medicinal importance in the herbal medicine industry becomes a challenge. The complexity of this process can be reduced by dereplication strategies. The current study includes a method based on high-performance liquid chromatography (HPLC), using the evaporative light scattering detector (ELSD) to identify the 12 most common secondary metabolites in plant extracts. Twelve compounds including rutin, taxifolin, quercetin, apigenin, kaempferol, betulinic acid, oleanolic acid, betulin, lupeol, stigmasterol, and beta-sitosterol were analyzed simultaneously. The polarity of the compounds varied greatly from highly polar (flavonoids) to non-polar (triterpenes and sterols). This method was also tested for HPLC-DAD and HPLC-ESI-MS/MS analysis. Oleanolic acid and ursolic acid could not be separated in HPLC-ELSD analysis but were differentiated using LC-ESI-MS/MS analysis due to different fragment ions. The regression values (R-2 > 0.996) showed good linearity in the range of 50-1000 mu g/mL for all compounds. The range of LOD and LOQ values were 7.76-38.30 mu g/mL and 23.52-116.06 mu g/mL, respectively. %RSD and % trueness values of inter and intraday studies were mostly <10%. This method was applied on 10 species of medicinal plants. The dereplication strategy has the potential to facilitate and shorten the identification process of common secondary metabolites in complex plant extracts.
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| 2. |
- Bilal, Muhammad, et al.
(författare)
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DFT insights into surface properties of anti-perovskite 3D topological crystalline insulators : A case study of (001) surfaces of Ca3SnO
- 2021
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Ingår i: Physics Letters A. - : Elsevier. - 0375-9601 .- 1873-2429. ; 408
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Tidskriftsartikel (refereegranskat)abstract
- In this letter density functional theory calculations are used for investigating the structural, energetic and electronic properties of CaSn- and Ca2O-terminated (001) surfaces of anti-perovskite Ca3SnO. Our calculations indicate larger structural changes in case of the CaSn-terminated (001) surface of Ca3SnO, however, both CaSn- and Ca2O-terminated surfaces of Ca3SnO are found to be energetically stable. The electronic properties of (001) surfaces of Ca3SnO are examined by taking spin-orbit coupling into account. Comparison of the simulated results of electronic properties for the two (001) surfaces of Ca3SnO with experimentally reported hole carrier densities observed in p-type polycrystalline samples show good agreement.
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| 3. |
- Tehreem, Syeda, et al.
(författare)
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A UPLC-DAD-Based Bio-Screening Assay for the Evaluation of the Angiotensin Converting Enzyme Inhibitory Potential of Plant Extracts and Compounds : Pyrroquinazoline Alkaloids from Adhatoda vasica as a Case Study
- 2021
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Ingår i: Molecules. - : MDPI. - 1431-5157 .- 1420-3049. ; 26:22
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Tidskriftsartikel (refereegranskat)abstract
- Angiotensin converting enzyme (ACE) plays a crucial role in regulating blood pressure in the human body. Identification of potential ACE inhibitors from medicinal plants supported the idea of repurposing these medicinal plants against hypertension. A method based on ultra-performance liquid chromatography (UPLC) coupled with a diode array detector (DAD) was used for the rapid screening of plant extracts and purified compounds to determine their ACE inhibitory activity. Hippuryl-histidiyl-leucine (HHL) was used as a substrate, which is converted into hippuric acid (HA) by the action of ACE. A calibration curve of the substrate HHL was developed with the linear regression 0.999. The limits of detection and quantification of this method were found to be 0.134 and 0.4061 mM, respectively. Different parameters of ACE inhibitory assay were optimized, including concentration, incubation time and temperature. The ACE inhibition potential of Adhatoda vasica (methanolic-aqueous extract) and its isolated pyrroquinazoline alkaloids, vasicinol (1), vasicine (2) and vasicinone (3) was evaluated. Compounds 1-3 were characterized by various spectroscopic techniques. The IC50 values of vasicinol (1), vasicine (2) and vasicinone (3) were found to be 6.45, 2.60 and 13.49 mM, respectively. Molecular docking studies of compounds 1-3 were also performed. Among these compounds, vasicinol (1) binds as effectively as captopril, a standard drug of ACE inhibition.
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| 4. |
- Aziz, Nudrat, et al.
(författare)
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Erythroid induction activity of Aquilegia fragrans and Aquilegia pubiflora and identification of compounds using liquid chromatography-tandem mass spectrometry
- 2021
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Ingår i: JOURNAL OF KING SAUD UNIVERSITY SCIENCE. - : Elsevier. - 1018-3647 .- 2213-686X. ; 33:1
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Tidskriftsartikel (refereegranskat)abstract
- Aquilegia fragrans (AF) and Aquilegia pubiflora (AP) are the two medicinally important species of genus Aquilegia used for the treatment of various diseases and infections. This paper describes the potential of fetal hemoglobin induction activity of the methanolic extracts of AF and AP in K562 cell line. AF and AP have shown 27.147 +/- 1.376 and 32.786 +/- 1.048 percent erythroid induction, respectively at 15.625 (mg/mL) concentration which suggested that both plants can be the source of potential fetal hemoglobin inducers and may be used for the treatment of beta-thalassemia. Phytochemical analyses of both species were also evaluated by using high-resolution LC-ESI-QTOF-MS/MS techniques. A Total of thirty compounds were identified using positive and negative ionization modes. The identification was based on the matching of high-resolution masses, isotopic pattern, and MS/MS fragmentation. Several statistical analyses were performed to evaluate the distribution of compounds in both species. Identified compounds belong to various classes including flavonoids, steroids, lignans, terpenoids, benzofuran and coumarins. The established chemical fingerprints will be helpful in standardization and quality control of plant extracts.
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| 5. |
- Bhatti, Muhammad Salman, et al.
(författare)
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Repurposing of pharmaceutical drugs by high-throughput approach for antihypertensive activity as inhibitors of angiotensin-converting enzyme (ACE) using HPLC-ESI-MS/MS method
- 2021
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Ingår i: Arabian Journal of Chemistry. - : Elsevier. - 1878-5352 .- 1878-5379. ; 14:8
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Tidskriftsartikel (refereegranskat)abstract
- Angiotensin-converting enzyme (ACE) plays an important role in regulating blood pressure in the body by converting angiotensin-I into angiotensin-II. It is the basic component of Renin angiotensin aldosterone system (RAAS), imbalance of RAAS may leads to many cardiovascular and renal diseases. There are many marketed available drugs for the inhibition of ACE, but prolonged use of some drugs may cause the progressive side effects. Repurposing of existing drugs can be a way to find new inhibitors of ACE. In this study, a high-throughput and sensitive method of HPLC-ESI-QqQ-MS with good reproducibility (%RSD < 9.98) and linearity (R-2 = 0.999) was used to investigate the 77 commercial drugs for their inhibitory potential as antihypertensive drugs. Among these drugs, 41 drugs were found active and 36 of them showed moderate to good inhibition with lowest IC50 = 272 mu M. This study showed that different pharmaceutical drugs can also be used as ACE inhibitor after necessary clinical trials or validation.
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| 6. |
- Kumari, Sindhia, et al.
(författare)
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Metabolomics approach to understand the hepatitis C virus induced hepatocellular carcinoma using LC-ESI-MS/MS
- 2021
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Ingår i: Arabian Journal of Chemistry. - : Elsevier. - 1878-5352 .- 1878-5379. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Hepatocellular carcinoma (HCC) is a typical cancer that has region specified analysis with the incidence of hepatitis C virus (HCV) infection. This study was conducted to improve the understanding of metabolic alterations associated with HCV induced HCC which can open up new strategies to monitor the high risk of HCC. Samples of the subjects with HCV, HCV induced chronic liver disease (CLD), HCV induced HCC, and healthy controls (HS) were collected after complete blood count (CBC), hepatitis viral load, st-fetoprotein (AFP), liver function tests, and albumin. A total of 147 serum samples including HCC (n = 11), CLD (n = 24), HCV (n = 71), and HS (n = 41) were analyzed by LC-ESI-MS/MS. The 21 compounds were found to be responsible for group discrimination after the application of chemometric tools. Nfructosyl tyrosine and hydroxyindoleacetic acid showed an increase in level whereas L-aspartylL-phenylalanine and thyroxine showed a consistent decrease in the progression of HCV to HCC in comparison with HS indicating their importance for early detection. The biological pathways such as glycerophospholipid metabolism, phenylalanine, tyrosine, and tryptophan biosynthesis, phenylalanine metabolism and tryptophan metabolism showed alteration in some metabolites. The method was internally validated by ROC plot showing AUC value for HS, HCV, CLD, and HCC as 0.99, 1, 1, and 0.89, respectively; while 16 blind samples were also validated with 93% specificity. The untargeted metabolomics investigation of HCV, CLD, and HCC can help to understand the progression of HCV-induced HCC. It reveals significant differences in metabolites to predict prognostic and diagnostic markers. (C) 2020 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.
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| 7. |
- Mugheri, Abdul Qayoom, et al.
(författare)
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Chemically Coupled Cobalt Oxide Nanosheets Decorated onto the Surface of Multiwall Carbon Nanotubes for Favorable Oxygen Evolution Reaction
- 2021
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Ingår i: Journal of Nanoscience and Nanotechnology. - : AMER SCIENTIFIC PUBLISHERS. - 1533-4880 .- 1533-4899. ; 21:4, s. 2660-2667
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Tidskriftsartikel (refereegranskat)abstract
- Cobalt oxide has been widely investigated among potential transition metal oxides for the electrochemical energy conversion, storage, and water splitting. However, they have inherently low electronic conductivity and high corrosive nature in alkaline media. Herein, we propose a promising and facile approach to improve the conductivity and charge transport of cobalt oxide Co3O4 through chemical coupling with well-dispersed multiwall carbon nanotubes (MWCNTs) during hydrothermal treatment. The morphology of prepared composite material consisting of nanosheets which are anchored on the MWCNTs as confirmed by scanning electron microscopy (SEM). A cubic crystalline system is exhibited by the cobalt oxide as confirmed by the X-ray diffraction study. The Co, O, and C are the only elements present in the composite material. FTIR study has indicated the successful coupling of cobalt oxide with MWCNTs. The chemically coupled cobalt oxide onto the surface of MWCNTs composite is found highly active towards oxygen evolution reaction (OER) with a low onset potential 1.44 V versus RHE, low overpotential 262 mV at 10 mAcm(-2) and small Tafel slope 81 mV dec(-1). For continuous operation of 40 hours during durability test, no decay in activity was recorded. Electrochemical impedance study further revealed a low charge transfer resistance of 70.64 Ohms for the composite material during the electrochemical reaction and which strongly favored OER kinetics. This work provides a simple, low cost, and smartly designing electrocatalysts via hydrothermal reaction for the catalysis and energy storage applications.
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| 8. |
- Mustafa, Ghulam M., et al.
(författare)
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Study of optoelectronic and transport properties of MgLu2Z4 (Z=S, Se) spinels for optoelectronic and energy harvesting applications
- 2021
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Ingår i: Materials Science in Semiconductor Processing. - : Elsevier. - 1369-8001 .- 1873-4081. ; 121
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Tidskriftsartikel (refereegranskat)abstract
- Intense research has been done to build materials that are potential candidates for energy storage applications. Spinels are of great interest in this respect because they have vast potential to be used in Mg-based batteries. To explore their energy storage as well as transport response, we calculate Mg-based spinels, namely MgLu2Z4 (ZS, Se). The full potential linearized augmented plane wave method has been used to examine their optoelectronic and transport response. An increase in the lattice constant has been observed by replacing S with Se, and our calculated values are in good agreement with those obtained experimentally. The Tran-Blaha modified Becke-Johnson exchange potential (TB-mBJ), has been used to study the optoelectronic and thermoelectric characteristics of the respective spinels. The dependence of these properties on the bandgap has also been observed. Replacing S with Se resulted in the transformation of the electronic bandgap from near-infrared to the visible region (MgLu2S4: 2.60 eV and MgLu2Se4: 2.00 eV). These results showed that these materials have the potential to be used in optoelectronic devices. The optical properties are discussed as a function of energy. Besides, the thermal transports are discussed with the help of Seebeck coefficient and figure of merit as a function of chemical potential and temperature.
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| 9. |
- Salo-Ahen, Outi M. H., et al.
(författare)
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Molecular Dynamics Simulations in Drug Discovery and Pharmaceutical Development
- 2021
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Ingår i: Processes. - : MDPI. - 2227-9717. ; 9:1
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Forskningsöversikt (refereegranskat)abstract
- Molecular dynamics (MD) simulations have become increasingly useful in the modern drug development process. In this review, we give a broad overview of the current application possibilities of MD in drug discovery and pharmaceutical development. Starting from the target validation step of the drug development process, we give several examples of how MD studies can give important insights into the dynamics and function of identified drug targets such as sirtuins, RAS proteins, or intrinsically disordered proteins. The role of MD in antibody design is also reviewed. In the lead discovery and lead optimization phases, MD facilitates the evaluation of the binding energetics and kinetics of the ligand-receptor interactions, therefore guiding the choice of the best candidate molecules for further development. The importance of considering the biological lipid bilayer environment in the MD simulations of membrane proteins is also discussed, using G-protein coupled receptors and ion channels as well as the drug-metabolizing cytochrome P450 enzymes as relevant examples. Lastly, we discuss the emerging role of MD simulations in facilitating the pharmaceutical formulation development of drugs and candidate drugs. Specifically, we look at how MD can be used in studying the crystalline and amorphous solids, the stability of amorphous drug or drug-polymer formulations, and drug solubility. Moreover, since nanoparticle drug formulations are of great interest in the field of drug delivery research, different applications of nano-particle simulations are also briefly summarized using multiple recent studies as examples. In the future, the role of MD simulations in facilitating the drug development process is likely to grow substantially with the increasing computer power and advancements in the development of force fields and enhanced MD methodologies.
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| 10. |
- Syed, Muzna, et al.
(författare)
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Chemical fingerprinting of three Anemone species and an adulteration study to detect cross mixing of medicinal plants by HPLC-HR-ESI-MS/MS method
- 2021
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Ingår i: JOURNAL OF KING SAUD UNIVERSITY SCIENCE. - : Elsevier. - 1018-3647 .- 2213-686X. ; 33:5
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Tidskriftsartikel (refereegranskat)abstract
- The adulteration of plant raw materials used for the preparation of herbal drugs with foreign plant material is one of the important issues in the quality control of herbal products. Chemical fingerprinting is a well-known approach for the characterization of secondary metabolites associated with the plant species and can be used for quality control of plant material. The current study centred on the development of chemical fingerprinting of three medicinal plants of genus Anemone including A. obtusiloba, A. falconeri and A tetrasepala through identification of their metabolites using LC-ESI-QTOF-MS/ MS analysis. Thirty compounds were identified by using high-resolution positive and negative electrospray-ionization (ESI) modes and MS/MS analysis. The identified compounds belong to diterpenoids, alkaloids, phenols, flavonoids and other classes and their distribution among the analysed species was studied using different statistical tools. Moreover, an LC-HR-ESI-MS/MS method was developed to detect the cross mixing of A. obtusiloba with Ziziphus jujuba. Seven chromatographically differentiative peaks confined to A. obtusiloba were selected to detect its contamination in adulterated samples. The method was able to detect as low as 20% mixing of A. obtusiloba in Z. jujuba. This study can play a significant role to manage the quality control of herbal medicines and to identify lead natural products of these plants.
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| 11. |
- Zulfiqar, Waqas, et al.
(författare)
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Revisiting the structural, electronic and photocatalytic properties of Ti and Zr based perovskites with meta-GGA functionals of DFT
- 2021
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Ingår i: Journal of Materials Chemistry C. - UK : Royal Society of Chemistry. - 2050-7526 .- 2050-7534. ; 9:14, s. 4862-4876
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Tidskriftsartikel (refereegranskat)abstract
- The strongly constrained and appropriately normed (SCAN) functional of density functional theory (DFT) conforms to all possible exact constraints required of a meta-GGA functional and offers good approximations for structural and energetic properties of solids in comparison to experiments. However, SCAN is unable to fully overcome the underestimation of band gap for perovskite oxide materials suitable for photocatalysis. In the present work, we use a combination of meta-GGAs SCAN and modified Becke–Johnson local density approximation (mBJ-LDA) potential functional to accurately compute the structural, energetic, mechanical, vibrational and optoelectronic properties of Ti and Zr based ABO3 (A = Sr, Ba and B = Ti and Zr) perovskite oxides. In addition to evaluating their physical properties, the potential applications of these materials as photocatalyst operating in the UV region of the electromagnetic spectrum are also examined. We show that the structural, energetic, mechanical and vibrational properties calculated using SCAN are in better agreement with experimental data as compared to the commonly used semi-local functionals of DFT. However, the optoelectronic properties of the large band gap Ti and Zr based perovskite oxides are further improved if computed with the mBJ-LDA potential functional, whereby an even higher level of accuracy than with SCAN is achieved, with results that are comparable to the computationally expensive hybrid DFT functionals. On the whole, our DFT calculations indicate that a combination of SCAN and mBJ-LDA functionals for exploring the physical properties of large band gap perovskite oxides provide the means for identifying photocatalysts suitable for hydrogen production at low computational costs.
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