Solomiia Kozachok

Black-eyed Susan (Rudbeckia hirta L.), a flowering plant with various traditional medicinal uses, has recently garnered interest for its therapeutic properties. However, little is known about the potential therapeutic activities of the plant species. The current study focused on conducting a comprehensive investigation into the chemical composition and bioactivity of black-eyed Susan cultivated in Romania. Untargeted metabolite profiling and UHPLC-HR-MS phytochemical analysis of the studied extract revealed the presence of more than 250 compounds pertaining to different classes, including sesquiterpene lactones, polyphenolic acids, flavonoids, amino acids, and fatty acids. The tested extract exhibited inhibitory activity against Gram-positive bacteria and showed promising antifungal activity. It also demonstrated potent antioxidant properties through iron chelation and 15-LOX inhibition capacities, as well as inhibition of cell growth, particularly on the MCF-7 cell line, suggesting potential anticancer effects. Therefore, current research provides valuable information on the antioxidant, antimicrobial, and antitumor potential of Rudbeckia hirta flowers. Implicitly, the discovery of such a wide range of biosubstances, together with the biological activity observed for the studied extract in these preliminary in vitro studies, paves the way for future investigation of the potential application of the plant in the pharmaceutical and nutraceutical sectors.

Based on the literature data from 1973 to 2022, this work summarizes reports on spiro-flavonoids with a spiro-carbon at the center of their structure and how this affects their isolation methods, stereochemistry, and biological activity. The review collects 65 unique structures, including spiro-biflavonoids, spiro-triflavonoids, spiro-tetraflavonoids, spiro-flavostilbenoids, and scillascillin-type homoisoflavonoids. Scillascillin-type homoisoflavonoids comprise spiro[bicyclo[4.2.0]octane-7,3′-chromane]-1(6),2,4-trien-4′-one, while the other spiro-flavonoids contain either 2H,2′H-3,3′-spirobi[benzofuran]-2-one or 2′H,3H-2,3′-spirobi[benzofuran]-3-one in the core of their structures. Spiro-flavonoids have been described in more than 40 species of eight families, including Asparagaceae, Cistaceae, Cupressaceae, Fabaceae, Pentaphylacaceae, Pinaceae, Thymelaeaceae, and Vitaceae. The possible biosynthetic pathways for each group of spiro-flavonoids are summarized in detail. Anti-inflammatory and anticancer activities are the most important biological activities of spiro-flavonoids, both in vitro and in vivo. Our work identifies the most promising natural sources, the existing challenges in assigning the stereochemistry of these compounds, and future research perspectives.

Fungi from the genus Diaporthe have been reported as plant pathogens, endophytes, and saprophytes on a wide range of host plants worldwide. Their precise identification is problematic since many Diaporthe species can colonize a single host plant, whereas the same Diaporthe species can inhabit many hosts. Recently, Diaporthe has been proven to be a rich source of bioactive secondary metabolites. In our initial study, 40 Diaporthe isolates were analyzed for their metabolite production. A total of 153 compounds were identified based on their spectroscopic properties—Ultraviolet-visible and mass spectrometry. From these, 43 fungal metabolites were recognized as potential chemotaxonomic markers, mostly belonging to the drimane sesquiterpenoid-phthalide hybrid class. This group included mainly phytotoxic compounds such as cyclopaldic acid, altiloxin A, B, and their derivatives. To the best of our knowledge, this is the first report on the metabolomic studies on Diaporthe eres species complex from fruit trees in the South-Eastern Poland. The results from our study may provide the basis for the future research on the isolation of identified metabolites and on their bioactive potential for agricultural applications as biopesticides or biofertilizers.

Tyrosinase is a key enzyme in the melanogenesis pathway. Melanin, the product of this process, is the main pigment of the human skin and a major protection factor against harmful ultraviolet radiation (UVR). Increased melanin synthesis due to tyrosinase hyperactivity can cause hyperpigmentation disorders, which in consequence causes freckles, age spots, melasma, or postinflammatory hyperpigmentation. Tyrosinase overproduction and hyperactivity are triggered by the ageing processes and skin inflammation as a result of oxidative stress. Therefore, the control of tyrosinase activity is the main goal of the prevention and treatment of pigmentation disorders. Natural products, especially propolis, according to their phytochemical profile abundant in polyphenols, is a very rich resource of new potential tyrosinase inhibitors. Therefore, this study focused on the assessment of the tyrosinase inhibitory potential of six extracts obtained from the European propolis samples of various origins. The results showed the potent inhibitory activity of all tested propolis extracts towards commercially available mushroom tyrosinase. The four most active propolis extracts showed inhibitory activity in the range of 86.66–93.25%. Apart from the evaluation of the tyrosinase inhibition, the performed research included UHPLC–DAD–MS/MS (ultra high performance liquid chromatography coupled with diode array detection and tandem mass spectrometry) phytochemical profiling as well as antioxidant activity assessment using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the 2,2”-azino-bis(3-ethylbenzothiazoline-6-sulfuric acid (ABTS) radical scavenging tests. Moreover, statistical analysis was used to correlate the tyrosinase inhibitory and antioxidant activities of propolis extracts with their phytochemical composition. To summarise, the results of our research showed that tested propolis extracts could be used for skin cosmeceutical and medical applications.

Iphiona mucronata (Family Asteraceae) is widely distributed in the Eastern desert of Egypt. It is a promising plant material for phytochemical analysis and pharmacologic studies, and so far, its specific metabolites and biological activity have not yet been thoroughly investigated. Herein, we report on the detailed phytochemical study using UPLC-Q-TOF-MS approach. This analysis allowed the putative annotation of 48 metabolites belonging to various phytochemical classes, including mostly sesquiterpenes, flavonoids, and phenolic acids. Further, zebrafish embryotoxicity has been carried out, where 100 µg/mL extract incubated for 72 h resulted in a slow touch response of the 10 examined larvae, which might be taken as a sign of a disturbed peripheral nervous system. Results of in vitro testing indicate moderate cytotoxicity towards VERO, FaDu, and HeLa cells with CC₅₀ values between 91.6 and 101.7 µg/mL. However, selective antineoplastic activity in RKO cells with CC₅₀ of 54.5 µg/mL was observed. To the best of our knowledge, this is the first comprehensive profile of I. mucronata secondary metabolites that provides chemical-based evidence for its biological effects. A further investigation should be carried out to precisely define the underlying mechanisms of toxicity.

Y. schidigera contains a number of unusual polyphenols, derivatives of resveratrol and naringenin, called spiro-flavostilbenoids, which have potent in vitro anti-inflammatory, antioxidant, and moderate cholinesterase inhibitory activities. To date, these compounds have not been tested in vivo for the treatment of neurodegenerative diseases. The aim of the present study was to evaluate the effects of both single spiro-flavostilbenoids (yuccaol B and gloriosaol A) and phenolic fractions derived from Y. schidigera bark on scopolamine-induced anxiety and memory process deterioration using a Danio rerio model. Detailed phytochemical analysis of the studied fractions was carried out using different chromatographic techniques and Nuclear Magnetic Resonance (NMR). The novel tank diving test was used as a method to measure zebrafish anxiety, whereas spatial working memory function was assessed in Y-maze. In addition, acetylcholinesterase/butyrylcholinesterase (AChE/BChE) and 15-lipooxygenase (15-LOX) inhibition tests were performed in vitro. All pure compounds and fractions under study exerted anxiolytic and procognitive action. Moreover, strong anti-oxidant capacity was observed, whereas weak inhibition towards cholinesterases was found. Thus, we may conclude that the observed behavioral effects are complex and result rather from inhibition of oxidative stress processes and influence on cholinergic muscarinic receptors (both 15-LOX and scopolamine assays) than effects on cholinesterases. Y. schidigera is a source of substances with desirable properties in the prevention and treatment of neurodegenerative diseases.

The work is aimed at phytochemical characterization and In Vitro evaluation of antioxidant actions, anti-inflammatory effects, and cytotoxicity of purified extracts from three rupturewort (Herniaria L.) species, i.e., Herniaria glabra (HG), H. polygama (HP), and H. incana herb (HIh). The total phenolic content established in the purified extracts (PEs) of HIh, HP, and HG was 29.6, 24.0, and 13.0%, respectively. Thirty-eight non-saponin metabolites were identified using LC-HR-QTOF-ESI-MS; however, only 9 were common for the studied Herniaria species. The most abundant phenolic compound in HG-PE was narcissin (7.4%), HP-PE shared 3 major constituents, namely cis-2-hydroxy-4-methoxycinnamic acid 2-O-β-glucoside (cis-GMCA, 5.8%), narcissin (5.4%), and rutin (5.3%). Almost half of HIh phenolic content (14.7%) belonged to oxytroflavoside A (7-O-methylkaempferol-3-O-[3-hydroxy-3-methylglutaryl-(1→6)]-[α-rhamnopyranosyl-(1→2)]-β-galactopyranoside). Antioxidant properties of the Herniaria PEs were evaluated employing an experimental model of human blood plasma, exposed to the peroxynitrite-induced oxidative stress. The assays demonstrated significant reduction of oxidative damage to protein and lipid plasma components (estimated by measurements of 3-nitrotyrosine, protein thiol groups, thiobarbituric acid-reactive substances), and moderate protection of its non-enzymatic antioxidant capacity. Anti-inflammatory properties of the Herniaria PEs were evaluated In Vitro as inhibitory effects against cyclooxygenases (COX-1 and -2) and concanavalin A-induced inflammatory response of the peripheral blood mononuclear cells (PBMCs). None of the studied plants showed inhibitory effects on COXs but all purified extracts partly reduced the release of interleukin 2 (IL-2) and tumor necrosis factor-alpha (TNF-α) from PBMCs, which suggested their prospective ability to up-regulate inflammatory response of the cells. The purified extract from H. glabra turned out to be the most efficient suppressor of PBMCs’ inflammatory response. Additionally, cytotoxicity of purified Herniaria extracts on PBMCs was ruled out based on In Vitro studies.