Tagetes erecta L. is a popular ornamental plant of the Asteraceae family, which is widely cultivated not only for its decorative use, but also for the extraction of lutein. Besides carotenoid representatives, which have been extensively studied, other important classes of secondary metabolites present in the plant, such as polyphenols, could exhibit important biological activities. The phytochemical analysis of a methanolic extract obtained from T. erecta inflorescences was achieved using liquid chromatography–mass spectrometry (LC-MS) techniques. The extract was further subjected to a multistep purification process, which allowed the separation of different fractions. The total extract and its fractions contain several polyphenolic compounds, such as hydroxybenzoic and hydroxycinnamic acid derivatives, flavonols (especially quercetagetin glycosides), and several aglycons (e.g., quercetin, patuletin). One of the fractions, containing mostly quercetagitrin, was subjected to two different antioxidant assays (metal chelating activity and lipoxygenase inhibition) and to in vitro cytotoxicity assessment. Generally, the biological assays showed promising results for the investigated fraction compared to the initial extract. Given the encouraging outcome of the in vitro assays, further purification and structural analysis of compounds from T. erecta extracts, as well as further in vivo investigations are justified.

Zinnia elegans (syn. Zinnia violacea) is a common ornamental plant of the Asteraceae family, widely cultivated for the impressive range of flower colors and persistent bloom. Given its uncomplicated cultivation and high adaptability to harsh landscape conditions, we investigated the potential use of Z. elegans as a source of valuable secondary metabolites. Preliminary classification of compounds found in a methanolic extract obtained from inflorescences of Z. elegans cv. Caroussel was accomplished using HR LC-MS techniques. The extract was then subjected to solid-phase extraction and separation using Sephadex LH-20 column chromatography, which resulted in several fractions further investigated for their antioxidant properties through lipoxygenase inhibition and metal chelating activity assays. Moreover, following additional purification procedures, structures of some active ingredients were established by NMR spectroscopy. The investigated fractions contained polyphenolic compounds such as chlorogenic acids and apigenin, kaempferol, and quercetin glycosides. Antioxidant assays showed that certain fractions exhibit moderate 15-LOX inhibition (Fr 2, IC₅₀ = 18.98 μg/mL) and metal chelation (e.g., Fr 1-2, EC₅₀ = 0.714–1.037 mg/mL) activities as compared to positive controls (20.25 μg/mL for kaempferol and 0.068 mg/mL for EDTA, respectively). For Fr 2, the 15-LOX inhibition activity seems to be related to the abundance of kaempferol glycosides. The NMR analyses revealed the presence of a kaempferol 3-O-glycoside, and a guanidine alkaloid previously not described in this species.

This paper presents a simple and eco-friendly method for the synthesis of silver nanoparticles (AgNPs) using licorice (Glycyrrhiza glabra) root extract and the evaluation of their antioxidant activity. UV-Vis spectroscopy, FTIR, TEM and EDX methods were used to characterize the AgNPs. The UV-Vis spectrum shows the characteristic surface plasmon resonance peak at 430 nm. The synthesized AgNPs have a spherical shape and are capped by biomolecules. Furthermore, FTIR spectra and EDX analysis demonstrate the presence of phytochemicals from extract which act as reducing and stabilizing agents. The presence of elemental silver was demonstrated by the peak at 3 keV from EDX spectra. The results following the DPPH free radical scavenging assay suggest that AgNPs present a better antioxidant activity compared to that of the extract. Therefore, the obtained results confirm that licorice represents a source of biomolecules that can be used for synthesizing AgNPs with antioxidant potential. Keywords: licorice, green synthesis, silver nanoparticles, antioxidant activity

Plant extracts have been pivotal in medicine and pharmacognosy for centuries, housing an array of bioactive compounds with therapeutic potential. This field, dedicated to exploring the medicinal properties of natural products, delves into the varied chemical compositions of these extracts. From ancient remedies to modern pharmaceuticals, they have been indispensable in healthcare. Numerous drugs, including aspirin and morphine, find their roots in plant sources. Today, extracts obtained from plants like ginseng, echinacea, and turmeric are esteemed for their immune-boosting and anti-inflammatory properties. Lespedeza capitata, a legume native to the Americas is the focus of this article thanks to its compounds which have shown promising results. Our results showed that this species contains various polyphenols with good antioxidant properties. Herbal remedies often capitalize on the antimicrobial and antioxidant effects of plant extracts. Additionally, phytochemicals within these extracts offer promising avenues for treating diverse ailments, from diabetes to cancer. Standardized extraction processes guarantee the potency and uniformity of medicinal plant products, further bolstering their reliability in healthcare. Ongoing research into plant extracts continues to reveal their therapeutic potential, fostering novel drug discoveries and advancements in global healthcare.