Cytotoxic activity of actinomycetes Nocardia sp. and Nocardiopsis sp. associated with marine sponge Amphimedon sp

Cancer is a hazard life-threatening disease, which affect huge population worldwide. Marine actinomycetes are considered as promising source for potential chemotherapeutic agents. In our study, we carried out metabolic profiling for Nocardia sp. UR 86 and Nocardiopsis sp. UR 92 that were cultivated from the Red Sea sponge Amphimedon sp. to investigate their chemical diversity using different media conditions. The crude culture extracts were subjected to high-resolution mass spectrometry (HRMS) analysis. The chemical profiles of the different extracts of Nocardia sp. UR 86 and Nocardiopsis sp. UR 92 revealed their richness in diverse metabolites and consequently twenty compounds (1-20) were annotated. Moreover, the obtained extracts of the differently cultivated Nocardia sp. UR 86 and Nocardiopsis sp. UR 92 were investigated against three cell lines HepG2, MCF-7 and CACO2 and revealed the targeted cytotoxicity of Nocardia sp. and Nocardiopsis sp. metabolites against the three cell lines.

Correction: The metabolomic analysis of five Mentha species: cytotoxicity, anti-Helicobacter assessment, and the development of polymeric micelles for enhancing the anti-Helicobacter activity

Correction for ‘The metabolomic analysis of five Mentha species: cytotoxicity, anti-Helicobacter assessment, and the development of polymeric micelles for enhancing the anti-Helicobacter activity’ by Riham O. Bakr et al., RSC Adv., 2021, 11, 7318–7330, DOI: 10.1039/D0RA09334C.

Cytotoxic Activity and Metabolic Profiling of Fifteen Euphorbia Species

Euphorbia is a large genus of flowering plants with a great diversity in metabolic pattern. Testing the cytotoxic potential of fifteen Euphorbia species revealed highest activity of E. officinarum L. against human colon adenocarcinoma (CACO2) cell line (IC₅₀ 7.2 µM) and of E. lactea Haw. against human hepatoma (HepG2) and human breast adenocarcinoma (MCF-7) cell lines (IC₅₀ 5.2 and 5.1 µM, respectively). Additionally, metabolic profiling of the fifteen tested species, using LC-HRMS, for dereplication purposes, led to the annotation of 44 natural compounds. Among the annotated compounds, diterpenoids represent the major class. Dereplication approach and multivariate data analysis are adopted in order to annotate the compounds responsible for the detected cytotoxic activity. Results of Principle component analysis (PCA) come in a great accordance with results of biological testing, which emphasized the cytotoxic properties of E. lactea Haw. A similarity correlation network showed that the two compounds with the molecular formula C₁₆H₁₈O₈ and C₂₀H₃₀O₁₀, are responsible for cytotoxic activity against MCF-7 and HepG2 cell lines. Similarly, the compound with molecular formula C₁₈H₃₅NO correlates with cytotoxic activity against CACO2.

Application of metabolomics and molecular networking in investigating the chemical profile and antitrypanosomal activity of British bluebells (Hyacinthoides non-scripta)

Bulb, leaf, scape and flower samples of British bluebells (Hyacinthoides non-scripta) were collected regularly for one growth period. Methanolic extracts of freeze-dried and ground samples showed antitrypanosomal activity, giving more than 50% inhibition, for 20 out of 41 samples. High-resolution mass spectrometry was used in the dereplication of the methanolic extracts of the different plant parts. The results revealed differences in the chemical profile with bulb samples being distinctly different from all aerial parts. High molecular weight metabolites were more abundant in the flowers, shoots and leaves compared to smaller molecular weight ones in the bulbs. The anti-trypanosomal activity of the extracts was linked to the accumulation of high molecular weight compounds, which were matched with saponin glycosides, while triterpenoids and steroids occurred in the inactive extracts. Dereplication studies were employed to identify the significant metabolites via chemotaxonomic filtration and considering their previously reported bioactivities. Molecular networking was implemented to look for similarities in fragmentation patterns between the isolated saponin glycoside at m/z 1445.64 [M + formic-H]- equivalent to C64H104O33 and the putatively found active metabolite at m/z 1283.58 [M + formic-H]- corresponding to scillanoside L-1. A combination of metabolomics and bioactivity-guided approaches resulted in the isolation of a norlanostane-type saponin glycoside with antitrypanosomal activity of 98.9% inhibition at 20 µM.

Metabolomic-Guided Isolation of Bioactive Natural Products from Curvularia sp., an Endophytic Fungus of Terminalia laxiflora

Endophytic fungi associated with medicinal plants are a potential source of novel chemistry and biology. Metabolomic tools were successfully employed to compare the metabolite fingerprints of solid and liquid culture extracts of endophyte Curvularia sp. isolated from the leaves of Terminalia laxiflora. Natural product databases were used to dereplicate metabolites in order to determine known compounds and the presence of new natural products. Multivariate analysis highlighted the putative metabolites responsible for the bioactivity of the fungal extract and its fractions on NF-κB and the myelogenous leukemia cell line K562. Metabolomic tools and dereplication studies using high-resolution electrospray ionization mass spectrometry directed the fractionation and isolation of the bioactive components from the fungal extracts. This resulted in the isolation of N-acetylphenylalanine (1: ) and two linear peptide congeners of 1: : dipeptide N-acetylphenylalanyl-L-phenylalanine (2: ) and tripeptide N-acetylphenylalanyl-L-phenylalanyl-L-leucine (3: ).

Polyphenolic profile and bioactivity study of Oenothera speciosa Nutt. aerial parts

Two new flavonol glycosides, myricetin 4'-O-alpha-L-rhamnopyranoside (1) and quercetin 3'-O-alpha-L-rhamnopyranoside (2), together with a novel biflavonol compound, speciin (3), as well as eleven phenolic metabolites, namely myricitrin (4), europetin 3-O-alpha-L-(1)C(4)-rhamnopyranoside (5), quercitrin (6), hyperin (7), rhamnetin 3-O-beta-galacto-pyranoside (8), caffeic acid (9), caffeic acid methyl ester (10), chlorogenic acid (11), chlorogenic acid methyl ester (12), gallic acid (13) and gallic acid methyl ester (14), were identified from the 80 % methanol extract of the aerial parts (leaves and stems) of Oenothera speciosa Nutt. (Onagraceae). In addition myricetin (15), quercetin (16) and ellagic acid (17) were identified from the chloroform extract. The structures were established depending on their chemical and physical analyses (UV, HR-ESIMS, 1D and 2D NMR). It was found that 80 % aqueous methanol extract of O. speciosa is non-toxic to mice up to 5 g kg(-1)b wt. The investigated extract exhibited significant antihyperglycaemic and anti-inflammatory activities in a dose dependant manner. Also, the 80 % methanol extract, myricitrin(4) and hyperin(7) showed potent antioxidant activity in vitro using 1,1-diphenyl 2-picryl hydrazyl (DPPH) radical assay.