LC-HRMS/MS-Based Metabolomics Approaches Applied to the Detection of Antifungal Compounds and a Metabolic Dynamic Assessment of Orchidaceae.

The liquid chromatography-mass spectrometry (LC-MS)-based metabolomics approach is a powerful technology for discovering novel biologically active molecules. In this study, we investigated the metabolic profiling of Orchidaceae species using LC-HRMS/MS data combined with chemometric methods and dereplication tools to discover antifungal compounds. We analyze twenty ethanolic plant extracts from Vanda and Cattleya (Orchidaceae) genera. Molecular networking and chemometric methods were used to discriminate ions that differentiate healthy and fungal-infected plant samples. Fifty-three metabolites were rapidly annotated through spectral library matching and in silico fragmentation tools. The metabolomic profiling showed a large production of polyphenols, including flavonoids, phenolic acids, chromones, stilbenoids, and tannins, which varied in relative abundance across species. Considering the presence and abundance of metabolites in both groups of samples, we can infer that these constituents are associated with biochemical responses to microbial attacks. In addition, we evaluated the metabolic dynamic through the synthesis of stilbenoids in fungal-infected plants. The tricin derivative flavonoid- and the loliolide terpenoidfound only in healthy plant samples, are promising antifungal metabolites. LC-HRMS/MS, combined with state-of-the-art tools, proved to be a rapid and reliable technique for fingerprinting medicinal plants and discovering new hits and leads.

Design, synthesis and pharmacological assessment of new pyrazole compounds.

AIMS: This study investigated the antinociceptive and anti-inflammatory effects of new pyrazole compounds LQFM011(5), LQFM043(6) and LQFM044(7) as well as the mechanisms of action and acute in vitro toxicity. MAIN METHODS: The antinociceptive activity was evaluated using the acetic acid-induced abdominal writhing test, formalin-induced pain test and the Randall-Selitto test. The anti-inflammatory activity was evaluated using models of paw oedema and pleurisy induced by carrageenan; cell migration, the levels of tumour necrosis factor α (TNF-α) and myeloperoxidase (MPO) enzyme activity were evaluated. In addition, the ability to inhibit phospholipase A2 (PLA2) in vitro and docking in PLA2 were used. Acute oral systemic toxicity in mice was evaluated through the neutral red uptake assay. KEY FINDINGS: The synthesised compounds (5-7), delivered via gavage (p.o.) at 70, 140 or 280 µmol/kg, decreased the number of writhings induced by acetic acid; the three compounds (280 µmol/kg p.o.) reduced the paw licking time in the first and second phase of the formalin test and decreased the nociceptive threshold variation in the Randall-Selitto test. Furthermore, this dose reduced oedema formation, leucocyte migration (specifically through reduction in polymorphonuclear cell movement) and increased mononuclear cells. MPO activity and the levels of pro-inflammatory cytokines TNF-α were decreased. Evaluation of PLA2 inhibition via the docking simulation revealed more interactions of LQFM043R(6) and LQFM044(7), data that corroborated the half-maximal inhibitory concentration (IC50) of PLA2 inhibition in vitro. Therefore, LQFM011(5), LQFM043(6) and LQFM044(7) were classified with the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) as category 4.

Molecular docking and pharmacological/toxicological assessment of a new compound designed from celecoxib and paracetamol by molecular hybridization.

Nonsteroidal anti-inflammatory drugs are commonly used worldwide; however, they have several adverse effects, evidencing the need for the development of new, more effective and safe anti-inflammatory and analgesic drugs. This research aimed to design, synthesize and carry out a pharmacological/toxicological investigation of LQFM-102, which was designed from celecoxib and paracetamol by molecular hybridization. To evaluate the analgesic effect of this compound, we performed formalin-induced pain, hot plate and tail flick tests. The anti-inflammatory effect of LQFM-102 was evaluated in carrageenan-induced paw oedema and pleurisy tests. The biochemical markers indicative of toxicity-AST, ALT, GSH, urea and creatinine-as well as the index of gastric lesion after prolonged administration of LQFM-102 were also analyzed. In addition, the interaction of LQFM-102 with COX enzymes was evaluated by molecular docking. In all experimental protocols, celecoxib or paracetamol was used as a positive control at equimolar doses to LQFM-102. LQFM-102 reduced the pain induced by formalin in both phases of the test. However, this compound did not increase the latency to thermal stimuli in the hot plate and tail flick tests, suggesting an involvement of peripheral mechanisms in this effect. Furthermore, LQFM-102 reduced paw oedema, the number of polymorphonuclear cells, myeloperoxidase activity and TNF-α and IL-1ß levels. Another interesting finding was the absence of alterations in the markers of hepatic and renal toxicity or lesions of gastric mucosa. In molecular docking simulations, LQFM-102 interacted with the key residues for activity and potency of cyclooxygenase enzymes, suggesting an inhibition of the activity of these enzymes.

The novel piperazine-containing compound LQFM018: Necroptosis cell death mechanisms, dopamine D4 receptor binding and toxicological assessment.

Piperazine is a promising scaffold for drug development due to its broad spectrum of biological activities. Based on this, the new piperazine-containing compound LQFM018 (2) [ethyl 4-((1-(4-chlorophenyl)-1H-pyrazol-4-yl)methyl)piperazine-1-carboxylate] was synthetized and some biological activities investigated. In this work, we described its ability to bind aminergic receptors, antiproliferative effects as well as the LQFM018 (2)-triggered cell death mechanisms, in K562 leukemic cells, by flow cytometric analyses. Furthermore, acute oral systemic toxicity and potential myelotoxicity assessments of LQFM018 (2) were carried out. LQFM018 (2) was originally obtained by molecular simplification from LASSBio579 (1), an analogue compound of clozapine, with 33% of global yield. Binding profile assay to aminergic receptors showed that LQFM018 (2) has affinity for the dopamine D4 receptor (Ki = 0.26 µM). Moreover, it showed cytotoxicity in K562 cells, in a concentration and time-dependent manner; IC50 values obtained were 399, 242 and 119 µM for trypan blue assay and 427, 259 and 50 µM for MTT method at 24, 48 or 72 h, respectively. This compound (427 µM) also promoted increase in LDH release and cell cycle arrest in G2/M phase. Furthermore, it triggered necrotic morphologies in K562 cells associated with intense cell membrane rupture as confirmed by Annexin V/propidium iodide double-staining. LQFM018 (2) also triggered mitochondrial disturb through loss of ΔΨm associated with increase of ROS production. No significant accumulation of cytosolic cytochrome c was verified in treated cells. Furthermore, it was verified an increase of expression of TNF-R1 and mRNA levels of CYLD with no involviment in caspase-3 and -8 activation and NF-κB in K562 cells. LQFM018 (2) showed in vitro myelotoxicity potential, but it was orally well tolerated and classified as UN GHS category 5 (LD50 > 2000-5000 mg/Kg). Thus, LQFM018 (2) seems to have a non-selective action considering hematopoietic cells. In conclusion, it is suggested LQFM018 (2) promotes cell death in K562 cells via necroptotic signaling, probably with involvement of dopamine D4 receptor. These findings open new perspectives in cancer therapy by use of necroptosis inducing agents as a strategy of reverse cancer cell chemoresistance.