Preliminary Phytochemical and Biological Evaluation of Rudbeckia hirta Flowers.

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.

Spiro-Flavonoids in Nature: A Critical Review of Structural Diversity and Bioactivity.

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.

Absolute configuration of spiro-flavostilbenoids from Yucca schidigera Roezl ex Ortgies: First indication of (2R)-naringenin as the key building block.

The absolute configurations of the known but unusual spiro-flavostilbenoids found in the bark of Yucca schidigera Roezl ex Ortgies, were determined by applying time-dependent density functional theory simulation of electronic circular dichroism spectra. The absolute configurations obtained were as follows: (2S,3R) for yuccaol A, yuccaol D and yuccalide A; (2S,3S) for yuccaol B, yuccaol C and yuccaol E; (2S,3S,2'S,3'S) for gloriosaol A; (2S,3R,2'S,3'R) for gloriosaol C; (2S,3S,2'S,3'R) for gloriosaol D; (2S,3R,2'S,3'S) for gloriosaol E. These findings indicate that the compounds are all biosynthetic derivatives either of (2R)-naringenin and trans-resveratrol or of trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene. In contrast, gloriosaols are direct derivatives of yuccaols (note that substituting by stilbenoid changes the absolute configuration of C-2 naringenin carbon to 2S). A putative mechanism for their biosynthesis is proposed taking into account key aspects of regio- and stereoselectivity. Yuccaol B and gloriosaol A showed in vitro moderate inhibitory effects against acetyl-/butyrylcholinesterases (AChE/BChE) with IC50 values of 43/81 and 45/65 µM respectively. The selectivity index values calculated from the IC50 values of BChE and AChE were 1.9 and 1.4. Molecular docking simulations showed their interaction with the peripheral anionic site of human AChE and the catalytic site of the human BChE.

Neuroprotective Effect of Yucca schidigera Roezl ex Ortgies Bark Phenolic Fractions, Yuccaol B and Gloriosaol A on Scopolamine-Induced Memory Deficits in Zebrafish.

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.

Comprehensive polyoxypregnane glycosides report in Caralluma quadrangula using UPLC-ESI-Q-TOF and their antioxidant effects in human plasma.

ETHNOPHARMACOLOGICAL RELEVANCE: Caralluma quadrangula (Forssk.) N.E.Br. (Syns: = Stapelia quadrangula Forssk. = Monolluma quadrangula Forssk.) is an indigenous member of the genus Caralluma and it is a rather common species on rocky hillsides in the southwestern part of Saudi Arabia. Several members of this genus have found medicinal uses in the treatment of rheumatism, diabetes, leprosy and as antiseptics and disinfectants. All parts are edible but rather more bitter and can cause diarrhea. AIM OF THE STUDY: The present report was tentatively elucidated the structure of acylated and non-acylated polyoxypregnane glycosides from Caralluma quadrangula. MATERIALS AND METHODS: The analyses were performed using an electrospray-ionization quadrupole time-of-flight (ESI-Q-TOF) mass spectrometer in both positive and negative ionization modes to explore fragmentation pathways. The antioxidant and prooxidant properties of the different mobility portions of human plasma were evaluated in vitro using thiobarbituric acid reactive substance assay (TBARS). RESULTS: The analyses showed sixty-five characteristic ion peaks which could be more efficient to assignment the aglycones and fragmentation sequences of sugar moieties. The used ionization modes provided consistent and/or complementary information for most of the pregnane glycosides, their fragmentation sequences, and their aglycones. A DFT Study was performed to elucidate the neutral loss of H2O molecules sequences from aglycones and the esterification linkage. CONCLUSIONS: This report could be useful to reduce material consuming and time in phytochemistry analysis of the different medicinal plants. The two portions significantly depleted TBARS were subjected to autoperoxidation assay in the presence of hydrogen peroxide.

Comparison of Phenolic Metabolites in Purified Extracts of Three Wild-Growing Herniaria L. Species and Their Antioxidant and Anti-Inflammatory Activities In Vitro.

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-ß-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)]-ß-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.

Determination of phenolic profiles of Herniaria polygama and Herniaria incana fractions and their in vitro antioxidant and anti-inflammatory effects.

The study is based on phytochemical profiling and in vitro evaluation of biological effects of phenolic acid derivatives-rich Herniaria fractions, isolated from two rupturewort (Herniaria L.) species, i.e. Herniaria incana Lam. (syn. H. besseri Fisch. ex Hornem) and H. polygama J. Gay (syn. H. odorata). For the first time, the composition of phenolic compounds of these species was extensively evaluated by both LC-HR-QTOF-ESI-MS and Nuclear Magnetic Resonance spectroscopy (NMR). LC-MS analyses of H. polygama revealed 72 tentatively identified compounds, while H. incana - 63. Only 8% of the metabolites reported in this work have been previously described for Herniaria spp. Most of the identified specialized metabolites were cinnamic and benzoic acid derivatives. Phenolic fraction of H. incana herb contained flavonoids as well. A multi-step chromatographic separation of phenolic fractions from H. polygama yielded three known cinnamic and one benzoic acid derivates, and from H. incana - 4 known flavonoids and one previously undescribed, i.e. rhamnocitrin-3-O-[3-hydroxy-3-methylglutaryl-(1 â†’ 6'')]-[α-rhamnopyranosyl-(1 â†’ 2'')]-ß-glucopyranoside. Antioxidant properties of the examined fractions (1-50 µg/ml) were assessed in human blood plasma under the conditions of peroxynitrite-induced oxidative stress. Measurements of well-known biomarkers such as 3-nitrotyrosine, protein thiol groups, thiobarbituric acid-reactive substances and the ferric reducing ability of blood plasma revealed the protective effect of Herniaria fractions against oxidative damage to blood plasma components. Furthermore, the examined fractions effectively ameliorated the inflammatory response of the concanavalin A-stimulated human peripheral blood mononuclear cells (PBMCs). Additionally, cellular safety of the fractions was confirmed in PBMCs.

Phytochemical Profile, Antioxidant Activity, and Cytotoxicity Assessment of Tagetes erecta L. Flowers.

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.

Leaves of Cleome amblyocarpa Barr. And Murb. And Cleome arabica L.: Assessment of nutritional composition and chemical profile (LC-ESI-MS/MS), anti-inflammatory and analgesic effects of their extracts.

ETHNOPHARMACOLOGICAL RELEVANCE: The Cleomaceae family is known for its richness in secondary metabolites and different Cleome species are used in folk medicine. Cleome amblyocarpa and Cleome arabica are medicinal herbs used in Tunisia and other North Africa countries to treat various diseases such as diabetes, rheumatism, colic, pain and digestive disorders. AIM OF THE STUDY: To our knowledge, few data are available about the nutritional value, phytochemical components and biological effects of C. arabica and C. amblyocarpa cultivated in Tunisia. For this reason, the present survey aimed to determine the nutritional value, bioactive compounds and pharmacological properties of the leaves of these two species of Cleome. MATERIALS AND METHODS: To characterize and determine the bioactive compounds in both extracts of leaves of Cleome species, ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) was used. The various nutritional parameters were analyzed, in particular the amounts of protein, carbohydrates, ash, fiber, and total lipids. Vitamin E and fatty acid profiles were also evaluated by HPLC-DAD-FLD and GC-FID, respectively. The acute toxic effects of leaf extracts in mice at concentrations of 100, 500 and 800 mg/kg body weight have been investigated. The anti-inflammatory effect of leaves extracts was examined by means of the in vitro and in vivo models. The in vivo anti-inflammatory test was assessed by means of the carrageenan induced paw edema in rats. For the in vitro anti-inflammatory assay, the red blood cells membrane stabilization and protein denaturation methods were employed. The analgesic effect of hydroalcoholic extracts of leaves was also assessed by acetic acid induced writhing model in mice. RESULTS: The phytochemical composition and the nutritional values of the leaves of C. amblyocarpa and C. arabica were determined. Our results revealed that the leaves of C. amblyocarpa are rich in flavonoids and glucosinolates. On the other hand, these latter metabolites are not present in the C. arabica extract and the leaves are characterized by the presence of flavones, methoxyflavones and their glycosides. Our findings revealed that the leaves of the two species contain a potential quantity of vitamins; proteins, carbohydrates and dietary fiber, and their hydroalcoholic extracts indicated substantial anti-inflammatory and antinociceptive activities in all the tests. Additionally, the data from the acute toxicity test proved that the leaf extracts did not cause any mortality or signs of toxicity in animals at doses up to 800 mg/kg CONCLUSIONS: The results obtained in this investigation demonstrated that the leaves of C. arabica and C. amblyocarpa are a valuable source of nutrients and active substances. Our observations support the traditional utilize of these two Cleome species for the treatment of painful diseases and as a source of natural anti-inflammatory agents.

Norditerpenoids with Selective Anti-Cholinesterase Activity from the Roots of Perovskia atriplicifolia Benth.

Inhibition of cholinesterases remains one of a few available treatment strategies for neurodegenerative dementias such as Alzheimer's disease and related conditions. The current study was inspired by previous data on anticholinesterase properties of diterpenoids from Perovskia atriplicifolia and other Lamiaceae species. The acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition by the three new natural compounds-(1R,15R)-1-acetoxycryptotanshinone (1), (1R)-1-acetoxytanshinone IIA (2), and (15R)-1-oxoaegyptinone A (3)-as well as, new for this genus, isograndifoliol (4) were assessed. Three of these compounds exhibited profound inhibition of butyrylcholinesterase (BChE) and much weaker inhibition of acetylcholinesterase (AChE). All compounds (1-4) selectively inhibited BChE (IC50 = 2.4, 7.9, 50.8, and 0.9 µM, respectively), whereas only compounds 3 and 4 moderately inhibited AChE (IC50 329.8 µM and 342.9 µM). Molecular docking and in silico toxicology prediction studies were also performed on the active compounds. Natural oxygenated norditerpenoids from the traditional Central Asian medicinal plant P. atriplicifolia are selective BChE inhibitors. Their high potential makes them useful candidate molecules for further investigation as lead compounds in the development of a natural drug against dementia caused by neurodegenerative diseases.

Gas chromatography-mass spectrometry (GM-MS) analysis and biological activities of the aerial part of Cleome amblyocarpa Barr. and Murb.

Cleome amblyocarpa Barr. and Murb is a medicinal plant widespread in North Africa and widely used in Tunisia to treat diabetes and colic. The non-volatile (polyphenols, flavonoids, tannins, and flavonols) and volatile compounds (GC-MS) of C. amblyocarpa leaves and stems have been studied. The antioxidant, antimicrobial, analgesic, and cytotoxic activities of hydroalcoholic extracts of C. amblyocarpa leaves and stems were also investigated. The major volatile components were ß-caryophyllene (46.9%), eugenol (25.6%), ethyl 3-methylpentanoate (16.2%), 7-epi-silphiperfol-5-ene (11.0%), and α-copaene (7.0%). The antioxidant activity has been evaluated using various in vitro assays, such as DPPH free radical scavenging activity, iron-chelating capability, and ability to inhibit lipid peroxidation (TBARS). The antibacterial and antifungal effectiveness of leaves and stems parts of Cleome amblyocarpa were investigated by means of the disc diffusion and microdilution techniques. The in vitro cytotoxicity of the hydroalcoholic extract of C. amblyocarpa on A549 and H1299 lung adenocarcinoma cells was determined using the crystal violet assay. The acute toxicity of the extracts on Swiss albino mice at the doses of 3000, 1500, and 500 mg/kg body weight was evaluated. The analgesic effect of leaves and stems extract was also determined by means of the acetic acid induced writhing test. The results indicated that the leaves have higher phenols, and flavonoids contents and potential antioxidant, antimicrobial, and anticancer activities in comparison to stem. In addition, the aerial part of C. amblyocarpa did not cause signs of toxicity or death in animals at doses up to 3000 mg/kg and have a significant analgesic activity.

Reinvestigation of Herniaria glabra L. saponins and their biological activity.

Twelve undescribed triterpenoid pentacyclic glycosides, medicagenic acid (3-O-ß-D-glucuronopyranosyl-28-O-{[ß-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-[α-L-rhamnopyranosyl-(1 → 3)]-4-O-acetyl-ß-D-fucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 3-O-ß-D-glucuronopyranosyl-28-O-{[α-L-rhamnopyranosyl-(1 → 2)]-[ß-D-apiofuranosyl-(1 → 3)]-4-O-acetyl-ß-D-fucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 3-O-ß-D-glucuronopyranosyl-28-O-{[α-L-rhamnopyranosyl-(1 → 2)]-3,4-O-diacetyl-ß-D-fucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 28-O-{[6-O-acetyl-ß-D-glucopyranosyl-(1 → 2)]-[2-O-acetyl-α-L-rhamnopyranosyl-(1 → 4)-ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 28-O-{[6-O-acetyl-ß-D-glucopyranosyl-(1 → 2)]-[3-O-acetyl-α-L-rhamnopyranosyl-(1 → 4)-ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 28-O-{[6-O-acetyl-ß-D-glucopyranosyl-(1 → 2)]-[4-O-acetyl-α-L-rhamnopyranosyl-(1 → 4)-ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 28-O-{[6-O-acetyl-ß-D-glucopyranosyl-(1 → 2)]-[ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid, 28-O-{[ß-D-glucopyranosyl-(1 → 2)]-[ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-12-ene-23,28-dioic acid), zanhic acid (3-O-ß-D-glucuronopyranosyl-28-O-{[ß-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-[α-L-rhamnopyranosyl-(1 → 3)]-4-O-acetyl-ß-D-fucopyranosyl-(1→)}2ß,3ß,16α-trihydroxyolean-12-ene-23,28-dioic acid, 3-O-ß-D-glucuronopyranosyl-28-O-{[ß-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-ß-D-fucopyranosyl-(1→)}-2ß,3ß,16α-trihydroxyolean-12-ene-23,28-dioic acid), 29-hydroxy-medicagenic acid (3-O-ß-D-glucuronopyranosyl-28-O-{[ß-D-glucopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)]-[α-L-rhamnopyranosyl-(1 → 3)]-4-O-acetyl-ß-D-fucopyranosyl-(1→)}-2ß,3ß,29ß-trihydroxyolean-12-ene-23,28-dioic acid) and herniaric acid (28-O-{[6-O-acetyl-ß-D-glucopyranosyl-(1 → 2)]-[α-L-rhamnopyranosyl-(1 → 4)-ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-(1→)}-2ß,3ß-dihydroxyolean-18-ene-23,28-dioic acid) were isolated from the whole plant extract of Herniaria glabra L. (Caryophyllaceae), wild growing in the Ukraine. In addition, five known triterpenoid saponins; i.e. herniariasaponins 1, 4, 5, 6, and 7 were also isolated. Their structures were elucidated by HRESIMS, 1D and 2D NMR spectroscopy, as well as by comparison with the literature data. Twelve herniariasaponins, the purified crude extract, and the saponin fraction were evaluated in vitro for their xanthine oxidase, collagenase, elastase, and tyrosinase inhibitory activity. Moreover, herniariasaponins 4, 5, and 7 were screened for their cholinesterase inhibitory potential. As a result, no or low inhibition towards the mentioned enzymes was observed.

Yuccalechins A-C from the Yucca schidigera Roezl ex Ortgies Bark: Elucidation of the Relative and Absolute Configurations of Three New Spirobiflavonoids and Their Cholinesterase Inhibitory Activities.

The ethyl acetate fraction of the methanolic extract of Yucca schidigera Roezl ex Ortgies bark exhibited moderate acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity (IC50 47.44 and 47.40 µg mL-1, respectively). Gel filtration on Sephadex LH-20 and further RP-C18 preparative HPLC of EtOAc fraction afforded 15 known and 3 new compounds, stereoisomers of larixinol. The structures of the isolated spirobiflavonoids 15, 26, and 29 were elucidated using 1D and 2D NMR and MS spectroscopic techniques. The relative configuration of isolated compounds was assigned based on coupling constants and ROESY (rotating-frame Overhauser spectroscopy) correlations along with applying the DP4+ probability method in case of ambiguous chiral centers. Determination of absolute configuration was performed by comparing calculated electronic circular dichroism (ECD) spectra with experimental ones. Compounds 26 and 29, obtained in sufficient amounts, were evaluated for activities against AChE and BChE, and they showed a weak inhibition only towards AChE (IC50 294.18 µM for 26, and 655.18 µM for 29). Furthermore, molecular docking simulations were performed to investigate the possible binding modes of 26 and 29 with AChE.

Chemical Profile and Antioxidant Activity of Zinnia elegans Jacq. Fractions.

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.

Cytotoxic Cardenolides from the Leaves of Acokanthera oblongifolia.

Three previously undescribed cardenolides, acovenosigenin A 3-O-α-L-acofriopyranoside (1: ), 14-anhydroacovenosigenin A 3-O-[ß-D-glucopyranosyl-(1″→4')-O-α-L-acofriopyranoside] (2: ), and 14-anhydroacovenosigenin A 3-O-[ß-D-glucopyranosyl-(1″→4')-O-α-L-acovenopyranoside] (3: ), together with the two already known ones, 14-anhydrodigitoxigenin 3-O-ß-D-glucopyranoside (4: ) and acospectoside A (5: ), were isolated from the leaves of Acokanthera oblongifolia. The influence of cardenolides 1:  - 3: and acovenoside A (found in the Acokanthera genus) on three cancer cell lines (HT29, HCT116, and AGS) was also investigated. The most promising results, in comparison with oxaliplatin, were obtained for compound 1: , which was found to be highly cytotoxic for all tested cell lines, HT29 (IC50 = 63.49 nM), HCT116 (IC50 = 67.35 nM), and AGS (IC50 = 80.92 nM). Unfortunately, 1: also showed similar toxicity towards normal lymphocytes (IC50 = 98.03 nM).

Structural and quantitative changes of saponins in fresh alfalfa compared to alfalfa silage.

BACKGROUND: Alfalfa (Medicago sativa) is an important legume used in animal feed. The primary objective of the present study was to analyze and trace the individual saponins in fresh and ensiled alfalfa of ten varieties, with the aim of evaluating the structural changes that saponins undergo during ensiling. A secondary objective was to examine whether any of the changes in saponin content were associated with changes in the basic nutrient composition of the ensiled alfalfa. RESULTS: The total saponin concentration increased when the fresh alfalfa was processed into silage. Three of the zanhic acid glycosides were degraded substantially, whereas the other two increased in all the tested varieties. Five of the seven medicagenic acid glycosides were not changed, whereas the remaining saponins completely disappeared. Finally, two glycosides of soyasapogenol B displayed an inverse relationship to each other. CONCLUSION: The nutrient content of fresh material and silages remained relatively constant, with some variations in the crude protein content of the selected alfalfa varieties. The total concentration of saponins increased two- to three-fold after ensilation over the levels present in fresh alfalfa material. The increases in saponin concentration showed a negative linear relationship between protein on a dry matter basis and saponin content. These findings are significant because no known published data have shown this transformation in the ensiling of alfalfa. © 2018 Society of Chemical Industry.

γ-Pyrone compounds: flavonoids and maltol glucoside derivatives from Herniaria glabra L. collected in the Ternopil region of the Ukraine.

The phytochemical investigation of the whole plant extracts of Herniaria glabra L. (Caryophyllaceae) led to the identification and isolation of four known flavonoids, one known and three undescribed maltol derivatives, and benzyl ß-gentiobioside. The structures were established by extensive 1D and 2D NMR spectroscopic analyses, as well as HRESIMS data. For the first time in Herniaria genus, as well as in Caryophylaceae family the presence of apiorutin {quercetin 3-O-[(D-apio-ß-d-furanosyl-(1 → 2)-O-[-α-l-rhamnopyranosyl-(1 → 6)]-ß-d-glucopyranoside]} and licoagroside B {maltol 3-O-[6-O-(3-hydroxy-3-methylglutaroyl)]-ß-d-glucopyranoside} were revealed. Additionally, antioxidant actions of apiorutin, rutin, narcissin (isorhamentin 3-O-ß-d-rutinoside) and licoagroside B were assessed in human blood plasma, exposed to the peroxynitrite-induced oxidative stress in vitro. The isolates partly reduced oxidative (oxidation of thiol groups) and nitrative (tyrosine nitration) damage to blood plasma proteins, decreased plasma lipid peroxidation as well as enhanced the non-enzymatic antioxidant capacity of blood plasma. No cytotoxicity of the examined substances towards peripheral blood mononuclear cells was found.

Molecular modeling and in vitro approaches towards cholinesterase inhibitory effect of some natural xanthohumol, naringenin, and acyl phloroglucinol derivatives.

BACKGROUND: Many natural products, particularly phenolic compounds, have been reported to have a strong inhibition against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), the key enzymes in the pathology of Alzheimer's disease (AD). HYPOTHESIS: Therefore, we hypothesized that some xanthahumol, naringenin, and acyl phloroglucinol derivatives (1-14) isolated from Humulus lupulus L. (hops) may have an inhibitory potential against AChE and BChE. METHODS: Inhibitory potential of compounds 1-14 were tested against AChE and BChE using ELISA microtiter assay. Different molecular docking simulations, including IFD and GOLD protocols, were implemented to verify the interactions between the ligands and the active site amino acids and also their binding energies inside the catalytic crevices of AChE and BChE. ADME/Tox analysis were used to determine pharmacological activities of the compounds. RESULTS: Among them, 3­hydroxy­xanthohumol (IC50 = 51.25 ±â€¯0.88 µM) and xanthohumol (IC50 = 71.34 ±â€¯2.09 µM), displayed a moderate AChE inhibition in comparison to that of the reference (galanthamine, IC50 = 2.52 ±â€¯0.15 µM). In addition to 3­hydroxy­xanthohumol (IC50 = 63.07 ±â€¯3.76 µM) and xanthohumol (IC50 = 32.67 ±â€¯2.82 µM), 8-prenylnaringenin (IC50 = 86.58 ±â€¯3.74 µM) also showed micromolar-range inhibition against BChE (galanthamine, IC50 = 46.58 ±â€¯0.91 µM). Rest of the compounds were found to be either inactive or having inhibition below 50%. Prediction of pharmacokinetic studies suggested that all the ligands revealed acceptable drug-like profiles. Docking simulations demonstrate not only the prediction of ligand binding energies of the compounds inside the catalytic domains of the targets, but also highlight the critical amino acids contributing to stabilizations of the ligands. CONCLUSION: Our findings revealed that xanthohumol in particular could be considered as lead molecule to explore new cholinesterase inhibitors for AD.

Phenolic fractions from nine Trifolium species modulate the coagulant properties of blood plasma in vitro without cytotoxicity towards blood cells.

OBJECTIVE: The study covers an evaluation of the influence of extracts (1-50 µg/ml), isolated from aerial parts of nine Trifolium L. species (i.e. T. alexandrinum, T. fragiferum, T. hybridum, T. incarnatum, T. pallidum, T. pratense, T. resupinatum var. majus, T. resupinatum var. resupinatum and T. scabrum) on haemostatic properties of blood plasma. METHODS: The clot formation and fibrinolysis assay (CFF), blood clotting times, the extrinsic and intrinsic coagulation pathway-dependent polymerization of plasma fibrin were measured. The effects of plant extracts on amidolytic activity of thrombin were also evaluated and compared with argatroban, an antithrombotic drug. Cytotoxicity was assessed in a model of blood platelets and as the viability of peripheral blood mononuclear cells. KEY FINDINGS: While no changes in blood clotting times or fibrinolytic properties of blood plasma were found, some fractions impaired the blood plasma coagulation induced by the intrinsic coagulation pathway. Reduction in the maximal velocity of fibrin polymerization was also observed in the clot formation and fibrinolysis assay. No cytotoxicity of Trifolium extracts towards the investigated cells was recorded. CONCLUSIONS: The most efficient anticoagulant activity in plasma was found for T. fragiferum and T. incarnatum extracts, while the T. alexandrinum fraction was the most effective inhibitor of thrombin amidolytic activity.

Triterpenoid Components from Oak Heartwood (Quercus robur) and Their Potential Health Benefits.

For centuries oak wood (Quercus robur) has been used in aging of wines and spirits, which is based on pleasant flavors given to beverages by phenolics transferred to the liquid during the maturation process. Other metabolites, such as triterpenoids, can also be released. Searching for extractable triterpenoids in oak heartwood, 12 new, 1-12, and five known, 13-17, oleanane types were isolated and characterized. Their cytotoxicities were tested against cancer cells (PC3 and MCF-7) and lymphocytes. Breast cancer cells (MCF-7) were the most affected by triterpenoids, with roburgenic acid, 4, being the most active compound (IC50 = 19.7 µM). Selectivity was observed for compounds 1-3, 8, 9, and 16, exhibiting an IC50 > 200 µM against lymphocytes, while active against cancer cells. A galloyl unit attached to the triterpenoid moiety was established as the key feature for such effect. These results highlight the occurrence of triterpenoids in oak heartwood and their relevance for chemoprevention of breast cancer.