Journal of Chemistry

Vitex doniana (West African plum or black plum) is a plant with varying phytoconstituents and biological activities across different countries. In this study, essential oils extracted from the leaves and fruits of Vitex doniana cultivated in Ghana were investigated for their antimicrobial and antioxidant activities. The antioxidant actions of the essential oils were determined using hydrogen peroxide (H₂O₂), phosphomolybdenum, thiobarbituric acid reactive substances (TBARS), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. For both essential oils, the total antioxidant capacities ranged from 44 to 68 µg/g AAE, the IC₅₀ values for H₂O₂ scavenging activity were between 87 and 242 µg/mL, whereas that for DPPH assay were between 322 and 599 µg/mL. The IC₅₀ for the TBARS assay for both essential oils also ranged from 247 to 414 µg/mL. The antimicrobial activities of the essential oils were investigated using the broth dilution assay. The minimum inhibition concentration for the essential oils ranged from 12.5 to 50 mg/mL. Biofilm inhibitory activity was also evaluated for both essential oils, and the fruit essential oil showed a half-maximal inhibition of biofilm formation (BIC₅₀) at 44.40 ± 0.6 mg/mL, whereas the BIC₅₀ value of the leaf essential oil was 109.1 ± 0.9 mg/mL. The fruit essential oil was superior to the leaf essential oil in inhibiting the secretion of pyoverdine. Molecular docking analyses suggested that methyl cinnamate, ethyl cinnamate, p-menth-4-en-3-one, trans-α-ionone, benzyl benzoate, isobutyl cinnamate, and folic acid likely interacted with LasR and algC proteins, and hence, contributed to the inhibition of biofilm formation and pyoverdine secretion. Essential oils from Vitex doniana could, therefore, be exploited as a natural source of radical scavenging and antimicrobial agents and could be useful in the pharmaceutical, food, and cosmetic industries.

Antioxidants can be determined using a variety of analytical assays. The total of antioxidant properties, depending on the sum of the products of their concentrations and antioxidant powers in the sample, is usually called total antioxidant potential (TAP). The direct method developed by us, based on the voltammetric measurements, was used to determine the TAPs of selected herbs. However, it is expected that the detection limit of this assay will be much lower when the convection current is increased and the capacitive current is eliminated. Such conditions are found in electrochemical HPLC detection. The advantage of this method is the ability to perform measurements at different potentials, which is analogous to the measurements related to various radicals in indirect methods. Measurements performed at high potentials of the working electrode allow us to test weak antioxidants. It turned out that electrochemical methods provided additional information about the antioxidant properties of the herbs. Some of them have a large part of TAP caused by weak antioxidants in high concentrations. The obtained results were correlated with the TAP values related to DPPH (2, 2-diphenyl-1-picrylhydrazyl) radicals and the total content of polyphenols in the sample.

Steroid 5 alpha-reductase 2 (5αR-2) is a membrane-embedded protein that together with other isoforms plays a key role in the metabolism of steroids. This enzyme catalyzes the reduction of testosterone to the more potent ligand, dihydrotestosterone (DHT) in the prostate. Androgens, testosterone, and DHT play important roles in prostate growth, development, and function. At the same time, both testosterone and DHT have been implicated in the pathogenesis of benign prostate hyperplasia (BPH). Inhibition of the DHT formation, therefore, provides a therapeutic strategy that offers the possibility of preventing, delaying, or treating BPH. Currently, two steroidal drugs that inhibit 5αR-2, dutasteride and finasteride, have been approved for clinical use. These two come at a high cost and also portray undesirable sexual side effects which necessitate the need to find new chemotherapeutic alternatives for the disease. Based on the aforementioned, finasteride and dutasteride were subjected to scaffold hopping, fragment-based de novo design, molecular docking, and molecular dynamics simulations employing databases like ChEMBL, DrugBank, PubChem, ChemSpider, and Zinc15 in the identification of potential hits targeting 5αR-2. Altogether, ten novel compounds targeting 5αR-2 were identified with binding energies lower or comparable to finasteride and dutasteride, the main inhibitors for this target. Molecular docking and molecular dynamics simulations studies identify amino acid residues Glu57, Phe219, Phe223, and Leu224 to be critical for ligand binding and complex stability. The physicochemical and pharmacological profiling suggests the potential of the hit compounds to be drug-like and orally active. Similarly, the quality parameter assessments revealed the hits possess LELP greater than 3 implying their promise as lead-like molecules. The compounds A5, A9, and A10 were, respectively, predicted to treat prostate disorders with Pa (0.188, 0.361, and 0.270) and Pi (0.176, 0.050, and 0.093), while A8 and A9 were found to be associated with BPH treatment with Pa (0.09 and 0.127) and Pi (0.077 and 0.033), respectively. Structural similarity searches via DrugBank identified the drugs faropenem, acemetacin, estradiol valerate, and yohimbine to be useful for BPH treatment suggesting the de novo designed ligands as potential chemotherapeutic agents for treating this disease.

Tight sandstone gas has become one of the important unconventional resources. It is of great significance to study the pore throat structure of tight sandstone for the development of tight sandstone gas reservoirs. On the basis of previous research results, this paper studies the tight reservoir characteristics of Yanchang Formation by combining geological data with geophysical logging. The reservoir characteristics are described and studied in detail by ordinary thin section, casting thin section, graphic granularity, and scanning electron microscope experiment. The experimental results show that the reservoir sandstone types of long 6 segments are mainly lithic feldspathic sandstone and feldspathic lithic sandstone, with high component maturity and structural maturity. The components of cement mainly include authigenic clay minerals illite, chlorite, and carbonate minerals. The reservoir space is mainly composed of feldspar-dissolved pores and residual intergranular pores. Compaction and cementation are the decisive factors of pore reduction. At present, the average porosity of the reservoir is 8.33% and the average permeability is 0.12 × 10⁻³ μm², which belong to an ultralow porosity and ultralow permeability reservoir. On the basis of studying the origin, superimposition, and distribution of sand bodies and taking into account the sedimentary characteristics, origin, and trigger mechanism of gravity flow, a multisource sedimentary model is established in the study area, which is dominated by sandy debris flow, accompanied by turbidity current and local development of sandy slump. The thick massive sandstone with the most exploration significance in the study area is formed by the superimposition of multistage sandy clastic flow sediments along the gully in the direction of delta to lake. Summarizing the characteristics of reservoir development and evaluating and predicting it can provide geological basis for the next exploration and development of deep-water tight reservoirs in the study area.

The confusing use of Polygonati Rhizoma (PR) and Polygonati Odorati Rhizoma (POR) poses an unpredictable threat to the health of consumers. Sensitive, nondestructive, rapid, and multicomponent techniques for their detection are sought after. In this study, a low-cost, short-wavelength (898–1668 nm), and handheld near-infrared (NIR) spectrometer combined with multivariate spectral evaluation methods was used to establish calibration models for identifying PR and POR. NIR spectra were treated with a standard normal variate (SNV) before performing chemometric approaches. Then principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were tested for calibration model development. The PCA results showed that spectral differences existed between the two herbs. However, the evaluation techniques could not separate them with the required accuracy. The PLS-DA calibration model, on the other hand, could separate the two herbs according to their spectral information with the prediction accuracy of >98.3%. Thus, it has been proven that a rapid, green, and low-cost method to support on-site and practical inspection through a handheld NIR instrument has been established to identify PR and POR and ensure the safety of the clinical medication.

Topological indices are empirical features of graphs that characterize the topology of the graph and, for the most part, are graph independent. An important branch of graph theory is chemical graph theory. In chemical graph theory, the atoms corresponds vertices and edges corresponds covalent bonds. A topological index is a numeric number that represents the topology of underline structure. In this article, we examined the topological properties of prism octahedron network of dimension and computed the total eccentricity, average eccentricity, Zagreb eccentricity, geometric arithmetic eccentricity, and atom bond connectivity eccentricity indices, which are used to utilize the distance between the vertices of a prism octahedron network.