Lipid constituents of Trifolium resupinatum var. microcephalum

The two new compounds (3-methyl-l-nonene-3-ol and 2',3'-dih,ydroxy propyl pentadecanoate) and four known compounds were isolated from Trifolium resupinatum L. var. microcephalum Zoh. (Leguminosae). All the compounds were reported for the first time from this plant. The stuructures of the isolates were determined by I D, 2D NMR techniques and MS spectroscopy

New Bioflavonoids from Solanum nigrum L. by Anticholinesterase and Anti-tyrosinase Activities-guided Fractionation

T wo new biflavonoids, (8-hydroxy-3'-β-D-galactosyl-isoflavone)-2'-8''-(4'''-hydroxy-flavone)-biflavone (2); 2',3',5-trihydroxy-5''-methoxy-3''-O- α-glucosyl-3-4'"-O-biflavone (3) and along with apigenin (1) and quercetin-3-O-β-glucoside (4) were isolated by activity guided fractionation from the whole plant of Solanum nigrum L.. The structures were established on the basis of UV, IR, 1D, 2D NMR and HRESI-MS spectroscopic methods. The anticholinesterase activity was performed against acetylcholinesterase and butyrylcholinesterase – the chief enzymes of Alzheimers’ disease – using the Ellman method. The tyrosinase inhibitory activity was performed according to L -DOPA method. Since the ethyl acetate (IC 50: 90.6±0.3 µg/mL) and n-butanol (IC 50: 140.6±1.7 µg/mL) extracts exhibited good butyrylcholinesterase inhibitory activity, both were fractionated and the active fractions were used for isolation of the compounds. These both extracts were also exhibited better tyrosinase inhibitory activity (IC 50: 76.0±0.6, and 156.8±1.9 µg/mL, respectively). Tested enzyme inhibitory activities of S. nigrum were presented in this study for the first time

Potent tyrosinase inhibitors from Trifolium balansae

Trifolium balansae ( Leguminosae) yielded a phytylester, phytyl-1-hexanoate, three steroids, stigmast-5-ene-3 beta,26-diol, stigmast-5-ene-3-ol and campesterol, and an alcohol, pentacosanol which were reported for the first time from T. balansae. The structures of the isolates were determined by 1D and 2DNMR techniques and MS spectroscopy. Compounds 1 - 5 were tested for their enzyme tyrosinase activity. While compounds 1 and 5 did not show any inhibition against the enzyme tyrosinase, compounds 2, 3, and 4 exhibited potent inhibition against tyrosinase. Highly potent ( IC50 = 2.39 mu M) inhibition was found by compound 2, when compared with the standard tyrosinase inhibitors Kojic acid and L-mimosine

A new biflavonoid from <i>Solanum dulcamara</i> L. and investigation of anti-hyperglycaemic activity of its fruit extract

<div><p>A new biflavone, 6,2′,3″,5″,4‴-pentahydroxy-3,7″-biflavone, has been isolated from the fruits of <i>Solanum dulcamara</i> L., in addition to two known compounds, β-sitosterol and stigmasterol. Their structures were established on the basis of UV, IR, 1D, 2D NMR and HR-ESI-MS spectroscopic methods. The anti-hyperglycaemic effect of <i>S. dulcamara</i> was investigated using diabetic rats. The anti-hyperglycaemic activity of the fruit extract of <i>S. dulcamara</i> was presented for the first time in this study.</p></div

Antiinflammatory and antioxidant activities of Trifolium resupinatum var microcephalum extracts

The antiinflammatory and antioxidant activities of the ethanol extract of Ttifolium resupinatum L. var. microcephalum (Leguminosae) have been assessed on arthritic rats. The extract (1.35 and 13.5 mg/kg, i.p.) significantly reduced the paw edema induced by the complete Freund's adjuvant. Furthermore, it also inhibited lipid peroxidation. These effects of T resupinatum extract may be directly linked to the content in triterpene saponins and flavonoid compounds and consequently to their free radical scavenging activities

Antioxidant and Tyrosinase Inhibitory Activities of Flavonoids from <i>Trifolium nigrescens</i> Subsp. <i>petrisavi</i>

<i>Trifolium nigrescens</i> was researched for its chemical constituents for the first time. Bioassay-guided isolation of the EtOAc extract from the leaves of <i>T. nigrescens</i> resulted in the purification of a new biflavone, 4′′′,5,5″,7,7″-pentahydroxy-3′,3′′′-dimethoxy-3-<i>O</i>-β-d-glucosyl-3″,4′-<i>O</i>-biflavone (<b>1</b>) along with eleven known compounds consisting of three phenolics (<b>2</b>–<b>4</b>), and eight flavonoid glycosides (<b>5</b>–<b>12</b>). Their structures were determined by extensive 1D and 2D NMR, and MS data analyses. The isolated compounds were evaluated for their antioxidant activity and inhibitory activity on mushroom tyrosinase. Highly potent inhibitions were found by compounds <b>7</b> (IC₅₀ = 0.38 mM), <b>8</b> (IC₅₀ = 0.19 mM), and <b>12</b> (IC₅₀ = 0.26 mM) when compared with standard tyrosinase inhibitors kojic acid (IC₅₀ = 0.67 mM) and l-mimosine (IC₅₀ = 0.64 mM). The antioxidative effect of the isolated compounds and the extracts were determined by using <i>β-</i>carotene-linoleic acid, DPPH^• scavenging, ABTS^+• scavenging, superoxide scavenging, and CUPRAC assays. The experimental findings indicated that all the compounds demonstrated activity in all antioxidant activity tests employed except for the compounds <b>2</b>–<b>6</b>. Compounds <b>2</b>–<b>6</b> showed moderate activity only in ABTS^+• scavenging assay. The new compound <b>1</b> exhibited better activity than standard α-tocopherol in DPPH^• scavenging, and ABTS^+• scavenging assays. The results show that <i>T. nigrescens</i> can be regarded as a potential source of antioxidant compounds and tyrosinase inhibitors of significance in both the pharmaceutical and food industries

Evaluation of Trichoderma harzianum to control downy mildew disease in sunflower under field conditions based on changes in the metabolite profiles of roots

Two years of field testing were conducted in naturally Plasmopara halstedii-infested soils to assess the effectiveness of Trichoderma harzianum isolate (TRIC8) against downy mildew (P. halstedii) on sunflower (Helianthus annuus). Seed treatment with this antagonist offered protection of 73.64% in the first year. The effects of this treatment on oil content of the seeds and metabolite profiles of roots, along with disease severity, were evaluated in the second year by comparing to the fungicide treatment (Metalaxyl M). Oil content in seeds and metabolite profile in roots were studied using Nuclear Magnetic Resonance (NMR) and gas chromatography/mass spectrometry (GC/MS), respectively. TRIC8 and fungicide treatments were found to cause significantly lower disease severity when compared to that of the control, although weather conditions were more favorable for the disease in the second year than in the first year. The oil content in seeds with TRIC8 treatment was superior to that in seeds with fungicide treatment or control. The metabolites in roots from treated plants and disease severity were subjected to principal component analysis (PCA). TRIC8 treatment increased the accumulation of some alcohols [2-ethyl-2-methyltridecan-1-ol, 2-(propylamino)ethanol], aldehydes [2,5-bis(trimethylsilyloxy)benzaldehyde, dodecanal], alkanes (dotriacontane, eicosane, heneicosane, nonacosane, nonylcyclopropane, tetracontane, tetracosane), ketones [(1-hydroxycyclohexyl)-phenylmethanone, (4-methylphenyl)-phenylmethanone], an ester (6-ethyloctan-3-yl 6-bromohexanoate) and a terpene (falcarinol), which were among the metabolites that contributed over 0.70 in PC1 and were negatively correlated with disease severity. We suggest these metabolites might be involved in defense response of sunflower against P. halstedii in the field

Antioxidant and antidiabetic activities of hexane extract of Genista januensis var. lydia

The genus Genista L. (Fabaceae) has been of interest for human beings since ancient times with its cosmopolitan distribution. Since ?-amylase and ?-glucosidase are the chief enzymes of diabetes mellitus, this study aims to study the ?-amylase and ?-glucosidase inhibitory potential and antioxidant activity of Genista januensis var. lydia grown in the Trakya region. To the best of our knowledge, there has been no study on G. januensis var. lydia up to date. The ?-amylase/?-glucosidase inhibitory activity and antioxidant activity of the hexane extract of G. januensis var. lydia were studied by spectroscopic in vitro experiments to search the potential relationships of both activities. © 2022 Bulgarian Academy of Sciences, Union of Chemists in Bulgaria.Tekirdağ Namık Kemal Üniversitesi, TNKU: NKUBAP.01Acknowledgement: This study was funded by Scientific Research Projects Coordination Unit of Tekirdag Namık Kemal University. Project number: NKUBAP.01.ÖNAP.21.318