Antimicrobial activity of spiculisporic acid isolated from endophytic fungus Aspergillus cejpii of Hedera helix against MRSA.

The surge in multidrug-resistant pathogens worldwide has jeopardized the clinical efficiency of many current antibiotics. This problem steered many researchers in their quest to discover new effective antimicrobial agents from natural origins including plants or their residing endophytes. In this work, we aimed to identify the endophytic fungi derived from Hedera helix L. and investigate their potential antimicrobial activity. Bioguided fractionation approach was conducted to isolate the pure compounds from the most active fungal fraction. Out of a total of six different isolated endophytic fungal strains, only Aspergillus cejpii showed the highest activity against all tested microbial strains. The most active fraction was the dichloromethane/methanol fraction (DCM:MeOH), where it showed significant activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Serratia marcescens, Acinetobacter baumannii, Salmonella typhi, and three drug-resistant clinical isolate strains including Methicillin-resistant Staphylococcus aureus (MRSA, H1), Pseudomonas aeruginosa (PS 16), and Acinetobacter baumannii (ACT 322) using tetracyline and kanamycin as the control antibiotics. Bioguided fractionation of the active fraction led to the isolation of the γ-butenolide, spiculisporic acid. Structure elucidation was carried out using 1H and 13C-NMR spectroscopic analysis. The compound showed good antimicrobial activities with minimum inhibitory concentration (MIC) values ranging from 3.9 to 31.25 µg/mL against all tested strains. Gas chromatography coupled to mass spectrometry (GC-MS) profiling was also carried out to identify the metabolites in the microbial crude extract. In conclusion, endophytic fungi, Aspergillus cejpii, isolated from Hedera helix L. roots showed promising antimicrobial activity which merits further in-depth investigations for potential utilization as a source of new antibiotics in the future. It can also be considered as a novel source for spiculisporic acid.

LC-ESI-MS/MS-Based Comparative Metabolomic Study, Antioxidant and Antidiabetic Activities of Three Lobelia Species: Molecular Modeling and ADMET Study.

The hydroethanol (70%) extracts of three Lobelia species (L. nicotianifolia, L. sessilifolia, and L. chinensis) were analyzed using LC-ESI-MS/MS. Forty-five metabolites were identified, including different flavonoids, coumarin, polyacetylenes, and alkaloids, which were the most abundant class. By applying Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) based on LC-ESI-MS/MS analysis, the three species were completely segregated from each other. In addition, the three Lobelia extracts were tested for their antioxidant activities using a DPPH assay and as antidiabetic agents against α-glycosidase and α-amylase enzymes. L. chinensis extract demonstrated significant antioxidant activity with an IC50 value of 1.111 mg/mL, while L. nicotianifolia showed mild suppressing activity on the α-glycosidase activity with an IC50 value of 270.8 µg/mL. A molecular simulation study was performed on the main compounds to predict their potential antidiabetic activity and pharmacokinetic properties. The molecular docking results confirmed the α-glycosidase inhibitory activity of the tested compounds, as seen in their binding mode to the key amino acid residues at the binding site compared to that of the standard drug acarbose. Furthermore, the predictive ADMET results revealed good pharmacokinetic properties of almost all of the tested compounds. The biological evaluation results demonstrated the promising activity of the tested compounds, aligned with the in silico results.

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-ß-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.