Background/Objectives: Verbena officinalis L. (common vervain) is a medicinal plant traditionally used and investigated in phytotherapy for its neuroprotective, antioxidant, and anti-inflammatory properties. This study aims to investigate the phytochemical diversity and biological activity of V. officinalis extracts prepared with different ratios of butanol and ethanol. Methods: Aerial parts of V. officinalis were extracted using four solvent systems: 100% butanol (B1), 75:25 (BE7.5), 50:50 (BE5), and 25:75 (BE2.5) butanol:ethanol mixtures. Metabolite profiling was conducted using liquid chromatography–high-resolution tandem mass spectrometry (LC-HRMS/MS). Antioxidant activities were evaluated through six assays: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric ion-reducing antioxidant capacity (CUPRAC), ferric-reducing antioxidant power (FRAP), metal-chelating ability (MCA), and the phosphomolybdenum assay (PMA). Enzyme inhibition assays targeted acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, and α-amylase. Antibacterial activity against Pseudomonas aeruginosa was tested via microdilution, while dominant phytochemicals were evaluated for binding affinity through molecular docking. Results: Seventy-five compounds, including phenolic acids, flavonoids, iridoids, phenylethanoids, and xanthones, were identified. BE5 extract exhibited the highest total phenolic content and strongest antioxidant capacity, while BE2.5 demonstrated the greatest antibacterial and metal-chelating effects. All extracts showed comparable AChE inhibition, with BE5 achieving the strongest tyrosinase and α-amylase inhibition. Docking studies confirmed high binding affinities of luteolin glucuronides to human and bacterial target enzymes. Conclusions: Solvent composition markedly influenced the chemical and biological profiles of V. officinalis extracts. BE5 and BE2.5 emerged as promising systems for obtaining bioactive fractions with therapeutic potential.

The valorization of post-distillation by-products represents a key strategy within circular economy frameworks, particularly for medicinal and aromatic plants of the Lamiaceae family. This study investigates, for the first time, the chemical composition and biological potential of the liquid residue obtained after hydrodistillation of Clinopodium albanicum (Griseb. ex K.Malý) Melnikov, an endemic Balkan species. Untargeted LC–HRMS/MS analysis revealed a complex metabolomic profile dominated by hydroxycinnamic acid derivatives, including caffeoylquinic acids, alongside a diverse flavonoid fraction comprising quercetin, kaempferol, apigenin, and acacetin derivatives. The presence of sugars and organic acids further indicated a broad metabolic composition. The evaporated liquid residual extract exhibited strong antioxidant activity (DPPH: 32.54, ABTS: 27.80, FRAP: 35.95 mmol GAE/100 mg). Pronounced antibacterial activity was observed against both Gram-positive and Gram-negative bacteria, including Staphylococcus aureus, MRSA, Listeria monocytogenes, Escherichia coli, and Pseudomonas aeruginosa (MICs 0.5–1 mg/mL). Additionally, the extract demonstrated antifungal activity against Candida auris and Candida parapsilosis, as well as strong antibiofilm effects against P. aeruginosa (up to 95.52% inhibition). Molecular docking supported these findings, revealing strong binding affinities of key phenolics toward the bacterial targets FabI and D-Ala-D-Ala ligase. Overall, the results highlight the potential of this by-product for nutraceutical and pharmaceutical applications.

Cucumis metuliferus E. Mey or kiwano/African horned melon is a good source of bioactive compounds of various pharmacological and industrial importance. This study investigated metabolomic shifts in in vitro cultivated kiwano plants over ten weeks of maturity time through GC-MS and LC-HRMS-MS untargeted analysis of volatile and non-volatile metabolites. Furthermore, in silico screening of the highly abundant volatile compounds from each sample was performed against three different proteins and enzymes of Candida spp. These results obtained from GC-MS and LC-HRMS-MS analysis highlight the potential of in vitro culture for enhancing the biosynthetic potential of C. metuliferus for sustainable and controlled production of target metabolites. Furthermore, this work also highlights the potential inhibitory properties of abundant volatile compounds in each stage of maturation period of C. metuliferus, providing a platform for further exploration of the therapeutic applications of C. metuliferus metabolites against Candida spp.