Increased soil salinity, and therefore accumulation of ions, is one of the major abiotic stresses of cultivated plants that negatively affect their growth and yield. Among Medicago species, only Medicago truncatula, which is a model plant, has been extensively studied, while research regarding salinity responses of two important forage legumes of Medicago sativa (M. sativa) and Medicago arborea (M. arborea) has been limited. In the present work, differences between M. arborea, M. sativa and their hybrid Alborea were studied regarding growth parameters and metabolomic responses. The entries were subjected to three different treatments: (1) no NaCl application (control plants), (2) continuous application of 100 mM NaCl (acute stress) and (3) gradual application of NaCl at concentrations of 50-75-150 mM by increasing NaCl concentration every 10 days. According to the results, M. arborea maintained steady growth in all three treatments and appeared to be more resistant to salinity. Furthermore, results clearly demonstrated that M. arborea presented a different metabolic profile from that of M. sativa and their hybrid. In general, it was found that under acute and gradual stress, M. sativa overexpressed saponins in the shoots while M. arborea overexpressed saponins in the roots, which is the part of the plant where most of the saponins are produced and overexpressed. Alborea did not perform well, as more metabolites were downregulated than upregulated when subjected to salinity stress. Finally, saponins and hydroxycinnamic acids were key players of increased salinity tolerance.

Chlorophenols (CPs) are environmental pollutants that are produced through various anthropogenic activities and introduced in the environment. Living organisms, including humans, are exposed to these toxic xenobiotics and suffer from adverse health effects. More specifically, 2,4-dichlorophenol (2,4-DCP) is released in high amounts in the environment and has been listed as a priority pollutant by the US Environmental Protection Agency. Bioremediation has been proposed as a sustainable alternative to conventional remediation methods for the detoxification of phenolic compounds. In this work, we studied the potential of fungal strains isolated as symbionts of marine invertebrates from the underexplored mesophotic coral ecosystems. Hence, the unspecific metabolic pathways of these fungal strains are being explored in the present study, using the powerful analytical capabilities of a UHPLC-HRMS/MS. The newly identified 2,4-DCP metabolites add significantly to the knowledge of the transformation of such pollutants by fungi, since such reports are scarce.

Anchusa officinalis (L.) interacts with various microorganisms including arbuscular mycorrhizal fungi (AMF). Recently, the AMF Rhizophagus irregularis MUCL 41833 has been shown to modulate the metabolome of A. officinalis. However, little information is available on the impact that different AMF species may have on primary and secondary plant metabolites. In this study, four AMF species belonging to the genus Rhizophagus (R. irregularis MUCL 41833, R. intraradices MUCL 49410, R. clarus MUCL 46238, R. aggregatus MUCL 49408), were evaluated for their potential to modulate A. officinalis metabolome under controlled semi-hydroponic cultivation conditions. An untargeted metabolomic analysis was performed using UHPLC-HRMS followed by a multivariate data analysis. Forty-two compounds were reported to be highly modulated in relation to the different AMF associations. Among them, six new secondary metabolites were tentatively identified including two acetyl- and four malonyl- phenylpropanoid and saponin derivatives, all presenting a common substitution at position C-6 of the glycosidic moiety. In addition, an enhanced accumulation of primary and secondary metabolites was observed for R. irregularis and R. intraradices, showing a stronger effect on A. officinalis metabolome compared to R. clarus and R. aggregatus. Therefore, our data suggest that different AMF species may specifically modulate A. officinalis metabolite production.

Chios mastic gum (CMG) exhibits several pharmacological activities that have been confirmed by numerous studies. These include antibacterial, anti-inflammatory, hypolipidemic, hypoglycemic, antiatheromatic, and benefits for against gastrointestinal disorders. However, studies focusing on CMG’s safety are limited. The aim of the present study is to evaluate the genotoxicity of CMG using the limit test on the mammalian erythrocyte micronucleus assay, in male Wistar rats. CMG was administered by gavage to 5 rats at 2000 mg/kg bw for 3 days, while 5 rats received the vehicle and 5 rats received cyclophosphamide (positive control). Satellite groups of 3 rats were included for the negative control and CMG-treated groups to collect plasma and bone marrow for the chemical analyses. All rats were observed for mortality and clinical signs of toxicity during the dosing period. Rats were euthanatized 20 h after the last treatment, necropsied, and bone marrow was collected for smear preparation. No mortality, clinical signs of toxicity, gross organ pathology, or body weight changes were observed in CMG-treated rats compared to the negative control group. No statistically significant alteration of polychromatic erythrocytes (PCE) and the per-thousand incidences of micronucleated PCE in the bone marrow of CMG-treated rats were observed. Bone marrow exposure to CMG was unambiguously confirmed by the detection of the characteristic CMG triterpenic acids in both bone marrow extract and plasma of CMG-treated rats by UHPLC-HRMS/MS analysis. In conclusion, CMG exhibited no genotoxic effects on bone marrow erythrocytes at the tested limit dose of 2000mg/kg body weight.

The CH2Cl2-MeOH extract of the Mediterranean sponge Crambe crambe was investigated via UHPLC-HRMS/MS employing manual dereplication and in silico mass spectrometry tools. A deconvolution approach was implemented toward the extensive metabolic characterization of the sample, resulting in the annotation of 53 compounds. The analysis of data-dependent HRMS/MS scans was conducted to establish fragmentation patterns characteristic of each crambescin A, B and C sub-families. Among the 39 compounds identified from these groups, 22 analogues were reported for the first time including 4 new homologous series that differed by the ratio of methylene units in the upper (n+2) and lower (m+2) alkyl side chains. More specifically, crambesins presenting m= 5 or 6 and n=5 (compounds 7, 11, 22 and 24) as well as m=5 or 6 and n=4 (compounds 5, 6, 8, 9, 12 and 14) were characterized. Additionally, 4 new crambescidin analogues (compounds 13, 15, 35 and 39) were also reported. The identity of the dereplicated features was further validated by studying crambescins spectral similarities through feature-based molecular networking approach. Overall, this study suggests UHPLC-HRMS/MS—through integration of manual and computational dereplication approaches—as a valuable tool for the investigation and high-throughput characterization of C. crambe metabolome.