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ABCG2 is a substantial member of the ABC transporter superfamily that plays a significant role in multidrug resistance in cancer. Until recently, the 3D structure of ABCG2 has not been resolved, which resulted in the limitation of developing potential ABCG2 inhibitors using structure‐based drug discovery. Herein, eMolecules, ChEMBL, and ChEBI databases, containing >25 million compounds, were virtually screened against the ABCG2 transporter in homodimer form. Performance of AutoDock4.2.6 software to predict inhibitor‐ABCG2 binding mode and affinity were validated on the basis of available experimental data. The explored databases were filtered based on docking scores. The most potent hits with binding affinities higher than that of experimental bound ligand (MZ29) were then selected and subjected to molecular mechanics minimization, followed by binding energy calculation using molecular mechanics‐generalized Born surface area (MM‐GBSA) approach. Furthermore, molecular dynamics simulations for 50 ns, followed by MM‐GBSA binding energy calculations, were performed for the promising compounds, unveiling eight potential inhibitors with binding affinities <−55.8 kcal/mol. Structural and energetic analyses demonstrated the stability of the eight identified inhibitors over the 50 ns MD simulation. This research sheds light on the potentiality of the identified ABCG2 inhibitors as a therapeutic approach to overcome multidrug resistance cancer therapy. [ABSTRACT FROM AUTHOR]

A new Tetrahydrofuran sesquiterpene 7,10‐Epoxy‐10‐methy‐dodeca‐1,6(14)‐diene‐3,4‐diol (1) along with three known Tetrahydrofuran sesquiterpene compounds 2,6,10‐trimethyl‐2,5:7,10‐dioxido‐dodeca‐3,11‐dien‐5‐ol (2), cis‐hydroxydavanone (3), and davana acid (4). All isolated metabolites were tested against MCF‐7, HCT‐116, and HepG‐2 cancer cell lines. Compound 2 showed potent activity against MCF‐7 (IC50 = 26 ± 0.4 μg/ml), HCT‐116 (IC50 = 30.4 ± 0.9 μg/ml), and HepG‐2 (IC50 = 20.5 ± 0.3 μg/ml) cancer cells. [ABSTRACT FROM AUTHOR]

In this study, genetic variability, antimicrobial activity and water-soluble vitamins content were investigated among Acacia ehrenbergiana, Acacia seyal, Acacia etbaica, Acacia tortilis and Acacia asak. Random Amplified Polymorphic DNA (RAPD), Inter Simple Sequence Repeats (ISSR) and mixed primers were used to evaluate the genetic variability among Acacia spp. 58 bands resulted from RAPD primers of which 51 unique bands, 7 polymorphic bands and no monomorphic bands with similarity values between 18.37% to 63.38%. ISSR primers showed 75 scorable bands of which 42 unique bands, 31 polymorphic bands and 2 monomorphic bands with similarity values ISSR (25% to 47.06%). Mixed primers showed 71 bands of which 41 unique bands, 29 polymorphic bands and one monomorphic band with similarity values ranged between 29.09% to 46.39%. RAPD and mixed primers separated Acacia ehrenbergiana from other investigated species while ISSR primers separated both Acacia etbaica and Acacia tortilis from other species. Antimicrobial activities were screened against six human pathogenic microorganisms (HPM) and four plant pathogenic fungi (PPF) by using agar well diffusion method. Except extract of dry bark of Acacia tortilis and fresh leaves of Acacia asak all others had significant antimicrobial activities against HPM and all extracts against PPF showed weak activities. High Performance Liquid Chromatography (HPLC) was used to estimate the vitamin B1, folic acid, B12 and B2 content among Acacia spp. The highest content of vitamin B1 and folic acid found in Acacia seyal fresh leaves, B12 in Acacia etbaica fresh leaves while B2 in Acacia asak dry bark. In conclusion, RAPD, ISSR and mixed primers showed ability to distinguish variability among Acacia spp., and those plants posses' natural antimicrobials agent and natural vitamins that could be used as an alternative to the synthetic drugs. [ABSTRACT FROM AUTHOR]

One of the important factors in molecular biology analysis is DNA extraction process to obtain high quality DNA. Previously, all attempts to extract DNA from date palm involved either the use of fresh leaves or germinated seeds. The aim of this study was to extract genomic DNA from various parts of three years old date palm fruit and to evaluate the genetic diversity among seven cultivars of date palm. The fruit of each cultivar was dissected into perianth, seed without embryo, zygotic embryo, and endocarp-mescocarp-epicarp to extract the DNA. The results showed that genomic DNA could be easily extracted in sufficient quantity from zygotic embryo. Both RAPD and ISSR markers could effectively determine the genetic relationship among date palm cultivars with polymorphism percentage ranging between 32.09% and 36.49% respectively. RAPD markers showed that cultivars with highest similarity value were Lbanah and Nabtat Ali (80.0%), followed by Khalas and Sukkary (73.81%), while the least were Ajwa and Safawi (59.56%). ISSR revealed that the highest similarity values were for Anbar and Khalas (88.0%), followed by Lbanah and Nabtat Ali (86.18%), while the least were Khalas and Safawi (73. 81%). [ABSTRACT FROM AUTHOR]

Altitudinal gradient-defined specific environmental conditions could lead to genetics and chemical variations among individuals of the same species. By using RAPD, ISSR, GC–MS and HPLC analysis, the genetic and chemical diversity of Ziziphus spina-christi plants at various altitudinal gradient namely; Abha (2227.86 m), Dala Valley (1424 m), Rakhma Valley (1000 m), Raheb Valley (505 m) and Al-Marbh (147 m) were estimated. RAPD markers revealed that the highest similarity value (40.22%) was between Raheb Valley and Al-Marbh while the lowest similarity (10.08%) was between Abha and Raheb Valley. Based on ISSR markers the highest similarity value (61.54%) was also between Raheb Valley and Al-Marbh, while the lowest similarity (26.84%) was between Abha and Rakhma Valley. GC–MS results showed the presence of various phytochemical constituents in each population. The dendrogram based on chemical compounds separated the Z. spina-christi grown at the highest elevations (Abha) from the populations in lower elevations. HPLC analysis showed that the leaves of Z. spina-christi plant contain considerable amount of vitamins including B 1 , B 12 , B 2 and folic acid. In conclusion , there is a close relation between altitudinal gradients, genetic diversity and chemical constituents of the leaves of Z. spina-christi plants. [ABSTRACT FROM AUTHOR]

Phytochemical studies of the aerial parts of Euphorbia rigida afforded three triterpenes: betulin (1), cycloart-23Z-ene-3, 25-diol (2) and cycloartan-3, 24, 25-triol (3), firstly isolated from this plant. The structures and relative stereochemistry were determined on the basis of extensive spectroscopic analyses, including 1D and 2D NMR experiments (1H NMR, 13C NMR, COSY, NOESY, HMQC and HMBC). [ABSTRACT FROM AUTHOR]

Alternaria tenuissima was isolated from tomato showing symptoms of leaf spot disease cultivated under greenhouse conditions from Asir region, Saudi Arabia. The ability of salicylic acid (SA) and the newly prepared bioactive matter "Agrileen" (AG) to suppress the leaf spot disease of tomato was evaluated. Exogenous application of SA (0.5 and 1.0 mM) or AG (2.5 and 5%) enhanced the growth and plant yield of tomato in addition to the reduction of infection with A. tenuissima. Photosynthetic pigments, total proteins, free proline and the relative water content of leaves were also enhanced when either SA or AG was applied. The protein pattern showed an increase in band intensity in plants treated with SA that express the increase in gene expression involved in resistance against stress conditions. The results confirmed that the application of SA or AG could protect tomato plants against A. tenuissima infection either through the direct strength of the defense system and a reduction of the severity of the pathogen. [ABSTRACT FROM AUTHOR]

Isolation and identification of the indigenous yeasts of the rotten date fruits for possible production of bioethanol and single-cell protein was the aim of this study. Results showed that a considerable amount of date fruits is subjected to unfavorable conditions of storage that induce their rot and spoilage. From the rotten date fruits, ten yeast isolates were obtained and genetically identified by the sequence of D1/D2 domain of the 26S rRNA gene and phylogenetic analysis. The identity of these yeasts was: Hanseniaspora guilliermondii, H. uvarum (2 strains), H. opuntiae, Pichia kudriavzevii (2 strains), Issatchenkia orientalis, Wickerhamomyces anomalus, Yarrowia lipolytica and Zygosaccharomyces rouxii. The ability of these strains to ferment 20% of the spoilage date fruit juice evaluated on laboratory scale. Results proved that P. kudriavzevii KKUY-0151 and H. uvarum KKUY-0153 yielded 67.48 and 67.37 g/L respectively, of bioethanol as the highest producers. However, H. uvarum KKUY-0078, H. guilliermondii KKUY-0009 and Z. Rouxii KKUY-0157 produced the highest fresh biomass weight 31.76, 30.96 and 30.69 g/L, respectively as a single cell protein production. The study is a pioneer to investigate the endemic yeasts of the rotten date fruits. It concludes that some of the indigenous yeasts of the rotten date fruits are promising organisms in recycling the substrate into valuable products such as bioethanol and single-cell protein. © 2014 Friends Science Publishers [ABSTRACT FROM AUTHOR]

A quantum chemical study was accomplished on the σ-hole interactions of the barely explored group IV elements, for the first time, in the absence and presence of the positively and negatively directed external electric field (EEF). The analyses of molecular electrostatic potential addressed the occurrence of the σ-hole on all the inspected tetrel atoms, confirming their salient versatility to engage in σ-hole interactions. MP2 energetic findings disclosed the occurrence of favorable σ-hole interactions within the tetrel bonding complexes. The tetrel bonding interactions became stronger in the order of C < Si < Ge < Sn for F-T-F 3 ···FH complexes with the largest interaction energy amounting to -19.43 kcal/mol for the optimized F-Sn-F 3 ···FH complex under the influence of +0.020 au EEF. The interaction energy conspicuously evolved by boosting the magnitude of the positively directed EEF value and declining the negatively directed EEF one. The decomposition analysis for the interaction energies was also executed in terms of symmetry-adapted perturbation theory, illuminating the dominant electrostatic contribution to all the studied complexes' interactions except carbon-based interactions controlled by dispersion forces. The outcomes that emerged from the current work reported significantly how the direction and strength of the EEF affect the tetrel-bonding interactions, leading to further improvements in the forthcoming studies of supramolecular chemistry and materials science., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

The versatility of the X-T-X 3 compounds (where T = C, Si, and Ge, and X = F, Cl, and Br) to participate in tetrel- and halogen-bonding interactions was settled out, at the MP2/aug-cc-pVTZ level of theory, within a series of configurations for (X-T-X 3 ) 2 homodimers. The electrostatic potential computations ensured the remarkable ability of the investigated X-T-X 3 monomers to participate in σ-hole halogen and tetrel interactions. The energetic findings significantly unveil the favorability of the tetrel···tetrel directional configuration with considerable negative binding energies over tetrel···halogen, type III halogen···halogen, and type II halogen···halogen analogs. Quantum theory of atoms in molecules and noncovalent interaction analyses were accomplished to disclose the nature of the tetrel- and halogen-bonding interactions within designed configurations, giving good correlations between the total electron densities and binding energies. Further insight into the binding energy physical meanings was invoked through using symmetry-adapted perturbation theory-based energy decomposition analysis, featuring the dispersion term as the most prominent force beyond the examined interactions. The theoretical results were supported by versatile crystal structures which were characterized by the same type of interactions. Presumably, the obtained findings would be considered as a solid underpinning for future supramolecular chemistry, materials science, and crystal engineering studies, as well as a fundamental linchpin for a better understanding of the biological activities of chemicals., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent for the COVID-19 pandemic, which generated more than 1.82 million deaths in 2020 alone, in addition to 83.8 million infections. Currently, there is no antiviral medication to treat COVID-19. In the search for drug leads, marine-derived metabolites are reported here as prospective SARS-CoV-2 inhibitors. Two hundred and twenty-seven terpene natural products isolated from the biodiverse Red-Sea ecosystem were screened for inhibitor activity against the SARS-CoV-2 main protease (M pro ) using molecular docking and molecular dynamics (MD) simulations combined with molecular mechanics/generalized Born surface area binding energy calculations. On the basis of in silico analyses, six terpenes demonstrated high potency as M pro inhibitors with Δ G binding ≤ -40.0 kcal/mol. The stability and binding affinity of the most potent metabolite, erylosides B, were compared to the human immunodeficiency virus protease inhibitor, lopinavir. Erylosides B showed greater binding affinity towards SARS-CoV-2 M pro than lopinavir over 100 ns with Δ G binding values of -51.9 vs. -33.6 kcal/mol, respectively. Protein-protein interactions indicate that erylosides B biochemical signaling shares gene components that mediate severe acute respiratory syndrome diseases, including the cytokine- and immune-signaling components BCL2L1 , IL2 , and PRKC . Pathway enrichment analysis and Boolean network modeling were performed towards a deep dissection and mining of the erylosides B target-function interactions. The current study identifies erylosides B as a promising anti-COVID-19 drug lead that warrants further in vitro and in vivo testing.