Molecular docking, SAR analysis and biophysical approaches in the study of the antibacterial activity of ceramides isolated from Cissus incisa

A New Ceramide from Cissus Aralioides Baker (Vitaceae) and its Antimicrobial Activity

Purification through repeated column chromatography over silica gel and Sephadex LH-20 of the ethanol extract of the stems of Cissus aralioides (Baker) Planch. resulted in the isolation of a new ceramide, aralioidamide A (1), along with five known compounds (2-6). Their structures were determined by the extensive analyses of their spectroscopic (1D and 2D NMR) and spectrometric data, and comparison with those reported in the literature. Aralioidamide A (1) displayed weak antibacterial activity (MIC=256 μg/mL) against Bacillus subtilis, Staphylococcus aureus and Shigella flexneri and was inactive (MIC>256 μg/mL) against the tested fungi.

Bioassay’s Directed Isolation-Structure Elucidation and Molecular Docking of Triterpenes from Persea duthiei against Biologically Important Microbial Proteins

The research work presented in this study is mainly concerned with the bioactivity-directed phytochemical and biological evaluation of Persea duthiei. Persea duthiei is a typical medicinal plant used to treat a variety of ailments such as asthma, edema, and bronchitis. Ethyl acetate, n-hexane, n-butanol, and compounds that are soluble in water were used to examine the antibacterial as well as antifungal capacities of the plant. The antibacterial activity of the soluble parts of ethyl acetate and n-hexane against Escherichia coli, Staphylococcus aureus, Salmonella typhi, and Bacillus subtilis was high, even though there was no activity against Pseudomonas aeruginosa. Likewise, the n-hexane and ethyl acetate fractions were found to have substantial efficacy against several fungal strains such as Aspergillus flavus, Aspergillus fumigates, Fusarium solani, and Aspergillus niger, but not against Candida glabrata. Among the studied fractions, the ethyl acetate soluble fraction had potent antibacterial activity against all of the tested species. This fraction was submitted to phytochemical analysis utilizing various chromatographic methods for the extraction of various pure components. As a consequence, four compounds were isolated, and their structures were elucidated using various spectroscopic methods such as IR, EIMS, HR-EIMS, ¹H-NMR, ¹³C-NMR, NOESY, COSY, HMBC, and HMQC. Urs-12-en-3β-ol (α-amyrine) (1), Urs-12-ene-2α-3β-diol (chamaedrydiol) (2), 3β-hydroxyurs-12-en-28-aldehyde (ursolic aldehyde) (3), and 12-oleanex-3β-ol (β-amyrine) (4) were extracted. Compounds 1, 2, 3, and 4 were examined for antibacterial and antifungal activity and found to have zones of inhibition ranging from 0 to 11 mm against tested bacteria strains and percent inhibition ranging from 0 to 25 percent against fungus strains. Compounds 1 and 4 showed strong efficacy against the investigated fungal species, with a 25% inhibition rate. In the case of antibacterial activity, compounds 4 and 1 showed potent activity with zones of inhibition of 11 mm and 10 mm, respectively. Compounds 2 and 3 were observed to have nonsignificant antimicrobial activity. However, docking studies reflected the complex formation of compound 1 with beta-hydroxyacyl-ACP dehydratase HadAB and S. aureus tyrosyl-tRNA synthetase and compound 2 with topoisomerase II DNA gyrase complex, and they were reported to have antibacterial properties. Similarly, compound 4 was discovered to be well compatible with the lanosterol 14-demethylase (fungal enzyme) and is thus regarded as having antifungal capabilities. Chimera software was used to identify the binding pockets of these complexes. These results indicated that Persea duthiei is a valuable source of medicinal compounds for medication development.

Antibacterial Effects of Commiphora gileadensis Methanolic Extract on Wound Healing

Commiphora gileadensis (CG) is a small tree distributed throughout the Middle East. It was traditionally used in perfumes in countries in this area. In Saudi Arabia, it was used to treat wounds burns and as an antidote to scorpion stings. This study aimed to evaluate the antimicrobial activity and cutaneous wound healing efficiency of the CG extracts using microbiological tests, rate of wound contraction and histopathological changes. CG plant were extracted using the methanol extraction technique; then, the methanolic extract was characterized using liquid chromatography coupled with mass spectrometry (LC−MS). Afterwards, a six-millimetre (mm) excision wound was induced in 60 male Balb/c mice. Mice were classified into two classes; each class consisted of three groups of 10 mice. In the non-infected wound class, the group I was assigned as control and received normal saline. Group II received gentamicin treatment, and group III treated with CG-methanolic extract. In the Staphylococcus aureus-infected class, group IV received normal saline, and groups V and VI were treated with gentamicin and CG-methanolic extract, respectively. The colonization of infected wounds was determined using colony-forming units (CFUs), and the percentage of wound contraction was measured in all groups. Finally, the histopathologic semi-quantitative determination of wound healing was evaluated by inflammatory cell infiltration, the presence of collagen fibres and granulation tissue, and the grade of re-epithelization. Composition analysis of the methanolic extract confirmed the presence of a high amount of ceramide (69%) and, to a lesser extent, hexosylceramide (18%) and phosphatidylethanolamine (7%) of the total amount. Additionally, there was a statistically significant difference between the percentage of wound contraction in the CG-treated and control groups in both Staphylococcus aureus-infected and non-infected wounds (p < 0.01). The colonization of the infected wounds was lower in the group treated with CG than in the control group (p < 0.01). In both non-infected and infected wounds, the CG-treated group showed significant statistical differences in inflammatory cell infiltration, collagen fibres, re-epithelization and granulation tissue formation compared with the control group (p < 0.01). The CG extract possesses antibacterial and anti-inflammatory properties that induce wound healing.

Metabolomic Profile and Cytotoxic Activity of Cissus incisa Leaves Extracts

Cissus incisa leaves have been traditionally used in Mexican traditional medicine to treat certain cancerous illness. This study explored the metabolomic profile of this species using untargeted technique. Likewise, it determined the cytotoxic activity and interpreted all data by computational tools. The metabolomic profile was developed through UHPLC-QTOF-MS/MS for dereplication purposes. MetaboAnalyst database was used in metabolic pathway analysis and the network topological analysis. Hexane, chloroform/methanol, and aqueous extracts were evaluated on HepG2, Hep3B, HeLa, PC3, A549, and MCF7 cancer cell lines and IHH immortalized hepatic cells, using Cell Titer proliferation assay kit. Hexane extract was the most active against Hep3B (IC50 = 27 ± 3 μg/mL), while CHCl3/MeOH extract was the most selective (SI = 2.77) on the same cell line. A Principal Component Analysis (PCA) showed similar profiles between the extracts, while a Venn diagram revealed 80 coincident metabolites between the bioactive extracts. The sesquiterpenoid and triterpenoid biosynthesis pathway was the most significant identified. The Network Pharmacology (NP) approach revealed several targets for presqualene diphosphate, phytol, stearic acid, δ-tocopherol, ursolic acid and γ-linolenic acid, involved in cellular processes such as apoptosis. This work highlights the integration of untargeted metabolomic profile and cytotoxic activity to explore plant extracts, and the NP approach to interpreting the experimental results.

Chiral separation and molecular simulation study of six antihistamine agents on a coated cellulose tri-(3,5-dimethylphenycarbamate) column (Chiralcel OD-RH) and its recognition mechanisms

Enantiomeric separation of six antihistamine agents was first systematically investigated on a cellulose-based chiral stationary phase (CSP), that is, cellulose tris-(3,5-dimethyl phenyl carbamate) (Chiralcel OD-RH), under the reversed-phase mode. Orphenadrine, meclizine, terfenadine, dioxopromethazine, and carbinoxamine enantiomers were completely separated under the optimized mobile phase conditions with resolutions of 5.02, 1.93, 1.68, 1.67, and 1.54, respectively. Mequitazine was partially separated with a resolution of 0.77. The influences of type and concentration of buffer salt, the pH of buffer solution, and the type and ratio of organic modifier on the chiral separation were evaluated and optimized. For a better insight into the enantiorecognition mechanisms, molecular docking was carried out via the Autodock software. The lowest binding energy and the optimal conformations of the analytes/CSP complexes were supplied, and the mechanisms of chiral recognition were determined. According to the results, the key interactions for the chiral recognition of these six analytes on CDMPC were π-π interactions, hydrophobic interactions, hydrogen bond interactions, and some special interactions.