Antimicrobial and α-glucosidase inhibitory activities of chemical constituents from Gardenia aqualla (Rubiaceae)

Myxaoside A, a new triterpenoid saponin from Cordia myxa L. (Boraginaceae)

The phytochemical study of Cordia myxa L. led to the isolation, through chromatographic techniques, of a new triterpenoid saponin, 3-O-[α-L-rhamnopyranosyl-(1→3)-(6-O-acetyl-β-D-glucopyranosyl)]-22β-hydroxyolean-12-ene (3) namely Myxaoside A, together with three known compounds, Soyasaponine I (1), oleanolic acid (2), and 3-O-acetyl-oleanolic acid (4). All structures were established, based on 1 & 2D-NMR spectroscopic analysis and comparison with previous published reports. Compound 1-4 were evaluated for their antibacterial activity on various strains of bacteria including Salmonella typhi, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Vibrio cholerae. It appears that compounds 1 and 3 were active on all the tested microbial species, while compounds 2 and 4, shown no significant effect on S. aureus and K. pneumoniae at low concentrations 6.5 mg/mL and 3.0 mg/mL.

Neuroprotective activity of Colocasia esculenta (L.) Schott leaves against monosodium glutamate-induced excitotoxicity in rats: phytochemical and molecular docking study

Colocasia esculenta (L.) Schott is a food crop with long history of use in treatment of various disorders including neurological diseases. The methanolic leaves extract (ME) and its n-butanol fraction (n-BF) demonstrated significant in vivo neuroprotective activity in monosodium glutamate induced excitotoxicity in rats. Sixteen and fifteen polyphenolic compounds were identified in n-BF and ME, respectively, using HPLC. Phytochemical investigation of n-BF followed by 1D (1H and 13C NMR) spectroscopic analyses led to isolation and identification of daucosterol (1), thermopsoside (2) and chrysoeriol 7-O-β-D-neohesperidoside (3) for the first time from genus Colocasia, in addition to orientin (4). LC/MS/MRM analysis of fraction V obtained from n-BF revealed identification of 13 polyphenolic compounds. Molecular docking of isolated compounds confirmed binding of all compounds at the target pocket with higher energy than crystallised ligand. The current study evaluated and confirmed the mechanistic aspects of neuroprotective activity of C. esculenta leaves for the first time.

In vitro and in silico docking and molecular dynamic of antimicrobial activities, alpha-glucosidase, and anti-inflammatory activity of compounds from the aerial parts of Mussaenda saigonensis

Twelve compounds were isolated from Mussaenda saigonensis aerial parts through phytochemical analysis and the genus Mussaenda is the first place where the compounds 4-6 and 11-12 have been found. Based on the ability to inhibit NO production in RAW264.7 cells, compound 2 has demonstrated the strongest anti-inflammatory activity in vitro with an IC50 of 7.6 μM, as opposed to L-NMMA's IC50 of 41.3 μM. Compound 12 was found to be the most effective inhibitor of alpha-glucosidase enzyme in vitro, with an IC50 value of 42.4 μM (compared to 168 μM for acarbose). Compounds 1-12 were evaluated in vitro for antimicrobial activity using the paper dish method. Compound 11 demonstrated strong antifungal activity against M. gypseum with a MIC value of 50 μM. In silico docking for antimicrobial activity, pose 90 or compound 11 docked well to the 2VF5 enzyme, PDB, which explains why compound 11 had the highest activity in vitro. Entry 2/pose 280 demonstrated excellent anti-inflammatory activity in silico. The stability of the complex between pose 280 and the 4WCU enzyme for anti-inflammatory activity has been assessed using molecular dynamics over a simulation course ranging from 0 to 100 ns. It has been found to be stable from 60 and 100 ns. The Tyr 159 (95%, H-bond via water bridge), Asp 318 (200%, multiple contacts), Met 273 (75%, hydrophobic interaction via water bridge), and Gln 369 (75%, H-bond via water bridge) interacted well within the time range of 0 to 100 ns. It has more hydrophilic or polar pharmacokinetics.

Cytotoxic potential of dihydrochalcones from Eriosema glomeratum and their semi-synthetic derivatives

In the search of cytotoxic dihydrochalcones, this investigation led to the isolation of seven compounds (1-7) from Eriosema glomeratum and the preparation of eight derivatives (8-15). The cytotoxicity of samples was evaluated against lung (A549), breast (MCF-7), and cervical (HeLa) human cancer cells. The CH2Cl2/MeOH extract of the aerial part had strong cytotoxicity against all cells [IC50 11.2 (MCF-7), 8.4 (HeLa) and 13.1 (A549) μg/mL]. A strong activity was also displayed by the n-hexane fraction on MCF-7 (IC50 11.2 μg/mL). The precursor 3 and the derivative 8 were specifically found as strong cytotoxic agents toward MCF-7 (7.6 μM) and HeLa (3.1 μM), respectively and were more effective than the positive control. Derivatives 8 (3.1 μM) and 9 (21.3 μM) against HeLa were most potent than their precursor 3 (23.7 μM). This is the first preparation of 8-14 as well as the cytotoxicity of 3, 4, 8-15, fractions, and extract.

Chemical constituents from Cordia myxa L. (Boraginaceae) and their antibacterial activity

Chemical investigation of Cordia myxa L. (Boraginaceae) resulted in the isolation of the following ten known compounds: 1-naphthaleneacetic-5-carboxy-1,2,3,4,4a,7,8,8a-octahydro-1,2,4a-trimethyl-[1S-(1α,2β, 4a,8aα)]-acid (1), hexacosanoate-1-glyceryl (2), 3β-urs-12,20(30)-diene-27,28-dioic acid (3), 3β-D-glucopyranosylurs-12,20(30)-diene-27,28-dioic acid (4), stigmasterol (5), stigmasterol-3-O-β-D-glucopyranoside (6), oleanolic-acid (7), 3-O-acetyl-oleanolic acid (8), betulin (9) and spinasterol-3β-O-D-glucopyranoside (10). The isolated compounds were characterised by using spectroscopic methods, 1D and 2D NMR, mass spectroscopy (ESI-MS) and by comparison with the literature data. To the best of our knowledge, compounds 1, 3, 4, 8 and 10 were isolated for the first time from the Cordia genus. This result improves the chemotaxonomy knowledge of the Cordia genus. The antibacterial activities were performed by the Muller-Hinton agar diffusion method. The antibacterial activities were studied on Salmonella typhi, Staphylococcus aureus, Vibrio cholerae, Pseudomonas aeruginosa and Escherichia coli ATCC 25922. Compounds 8 and 9, at 20.0 mg/mL resulted to be effective antimicrobial against E. coli, V. cholerae and P. aeruginosa.

Ternifoliasaponin, a new triterpenoid saponin from the roots of Gardenia ternifolia Schumach & Thonn (Rubiaceae)

A new triterpenoid saponin, Ternifoliasaponin (1), together with four known compounds (2-5) chikusetsusaponin IVa (2), chikusetsusaponin IVa methyl ester (3), bonushenricoside B (4) and Dianoside C (5) were isolated from roots of Gardenia ternifolia Schumach. & Thonn (Rubiaceae). The structures of isolated compounds were elucidated on the basis of spectroscopic analysis and chemical methods. The antibacterial activities of compounds (3), and (4) were performed by the Muller-Hinton agar diffusion method. The antimicrobial activities of the compounds were studied on Salmonella typhi (Enterobacteriaceae), Staphylococcus aureus and Pseudomonas aeruginosa microorganisms. Compound (3) at 25 mg/mL, showed moderately sensitive effect (8.0 ˂ DIZ ˂14.0 mm) on S. typhi, S. aureus and P. aeruginosa. Compound (4) at 25 mg/mL and compound (3) at 12.5 mg/mL exhibited moderately sensitive effect on S. typhi and S. aureus. Compound (4) inhibited moderately sensitive the S. typhi and P. aeruginosa colonies at 12.5 mg/mL.

Computer-aided drug repurposing to tackle antibiotic resistance based on topological data analysis

The progressive emergence of antimicrobial resistance has become a global health problem in need of rapid solution. Research into new antimicrobial drugs is imperative. Drug repositioning, together with computational mathematical prediction models, could be a fast and efficient method of searching for new antibiotics. The aim of this study was to identify compounds with potential antimicrobial capacity against Escherichia coli from US Food and Drug Administration-approved drugs, and the similarity between known drug targets and E. coli proteins using a topological structure-activity data analysis model. This model has been shown to identify molecules with known antibiotic capacity, such as carbapenems and cephalosporins, as well as new molecules that could act as antimicrobials. Topological similarities were also found between E. coli proteins and proteins from different bacterial species such as Mycobacterium tuberculosis, Pseudomonas aeruginosa and Salmonella Typhimurium, which could imply that the selected molecules have a broader spectrum than expected. These molecules include antitumor drugs, antihistamines, lipid-lowering agents, hypoglycemic agents, antidepressants, nucleotides, and nucleosides, among others. The results presented in this study prove the ability of computational mathematical prediction models to predict molecules with potential antimicrobial capacity and/or possible new pharmacological targets of interest in the design of new antibiotics and in the better understanding of antimicrobial resistance.

In vitro α-glucosidase inhibitory activity of isolated compounds and semisynthetic derivative from aerial parts of Erythrina senegalensis DC

The current study was conducted to isolate the phytoconstituents from Erythrina senegalensis leaves and stem bark and evaluate their inhibitory activity against α-glucosidase, digestive enzyme related to diabetes mellitus. Phytochemical investigation of the leaves resulted in the isolation of three saponins (3-5), two triterpenoids (7 and 8) and two steroids (10a and 10b) as inseparable mixture, while one saponin (6), one triterpenoid (9) and one mixture of two cinnamates (2a and 2b) were isolated from the stem bark. Except for compounds 2 b, 7, 8, 10a and 10 b all the isolated compounds are reported here for the first time from the genus Erythrina. Acetylation of the mixture of two cinnamates (2a and 2b) led to a new diester derivative (1) trivially called erythrinamate. The extracts and pure compounds (3, 4, 6) showed good α-glucosidase inhibitory activity compared to the standard drug acarbose. The findings suggest that saponins of E. senegalensis could be used to develop potential anti-hyperglycemic drugs.

Bioactive Evaluation of Ursane-Type Pentacyclic Triterpenoids: β-Boswellic Acid Interferes with the Glycosylation and Transport of Intercellular Adhesion Molecule-1 in Human Lung Adenocarcinoma A549 Cells

Ursane-type pentacyclic triterpenoids exert various biological effects, including anticancer and anti-inflammatory activities. We previously reported that ursolic acid, corosolic acid, and asiatic acid interfered with the intracellular trafficking and glycosylation of intercellular adhesion molecule-1 (ICAM-1) in human lung adenocarcinoma A549 cells stimulated with the pro-inflammatory cytokine interleukin-1α. However, the structure–activity relationship of ursane-type pentacyclic triterpenoids remains unclear. In the present study, the biological activities of seven ursane-type pentacyclic triterpenoids (β-boswellic acid, uvaol, madecassic acid, 3-O-acetyl-11-keto-β-boswellic acid, ursolic acid, corosolic acid, and asiatic acid) were investigated. We revealed that the inhibitory activities of ursane-type pentacyclic triterpenoids on the cell surface expression and glycosylation of ICAM-1 and α-glucosidase activity were influenced by the number of hydroxy groups and/or the presence and position of a carboxyl group. We also showed that β-boswellic acid interfered with ICAM-1 glycosylation in a different manner from other ursane-type pentacyclic triterpenoids.