Antioxidant activity optimization and GC-MS profile of aqueous extracts of Vernonanthura patens (Kunth) H. Rob. leaves

Abstract

The temperature and extraction time of aqueous extracts of Vernonanthura patens (Kunth) H. Rob. (AEVP) leaves obtained by decoction were optimized for maximum recovery of DPPH radical scavenging activity, ABTS⁺ inhibition activity, total phenolic content (TPC) and total flavonoids content (TFC) using response surface methodology (RSM). A central composite design (CCD) of 13 experimental runs was applied and second order polynomial models were used to describe the responses of the assessed extraction parameters. The optimized conditions: 79.79?°C and 126.23?minutes were found using the composite desirability function. The scavenging activity of assessed extracts could be correlated mostly to the presence of malic acid, succinic acid, α-ketoglutaric acid, citric acid, m-hydroxybenzoic acid, caffeic acid, inositol, and β-amyrin detected by gas chromatography-mass spectrometry (GC-MS). These results have not been reported and support the potential application of AEVP as natural source of antioxidants.     

The Antioxidant,Cytotoxic and Antimicrobial Potential of Phenolic Acids-Enriched Extract of Elicited Hairy Roots of Salvia bulleyana

Hairy root cultures are valuable sources of a range of phytochemicals. Among them, Salvia bulleyana root culture is a promising source of polyphenols, especially rosmarinic acid (RA), a phenolic acid depside with pleiotropic activity and a wide application in medicine and cosmetology. The aim of the study was to enhance the culture productivity by finding suitable elicitation protocol and to determine its biological potential in terms of antioxidant, anticancer and antimicrobial properties. The total content of phenols and the levels of particular constituents in root extracts were analyzed using HPLC-PDA. Among four elicitors tested (yeast extract; methyl jasmonate, MJA; trans-anethol; and cadmium chloride), MJA was found to be the most effective. The greatest boost in phenolic production (up to 124.4 mg/g dry weight) was observed after three-day treatment with MJA at 100 µM, with an almost 100% improvement compared to the controls (non-treated root culture). The hydromethanolic extract from the elicited culture exhibited strong antioxidant activity with IC₅₀ values of 11.1 µg/mL, 6.5 µg/mL and 69.5 µg/mL for DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)) and superoxide anion radical, respectively. Moreover, in concentrations of 0.5–5 mg/mL the extract inhibited the growth of LoVo, AGS and HeLa cell lines, but was safe for the L929 cells up to the concentration of 5 mg/mL. The extract also exhibited moderate antimicrobial activity. Thus, the results confirmed that elicitation can be a beneficial strategy for increase the phenolic acid biosynthesis in hairy roots of S. bulleyana, and that such a highly productive culture can show significant biological potential.     

Antioxidant and Antimicrobial Evaluation and Chemical Investigation of Rosa gallica var. aegyptiaca Leaf Extracts

Rosa gallica var. aegyptiaca is a species of flowering plant belonging to the Rosaceae family that plays an important role as a therapeutic agent for the treatment of specific types of cancer, microbial infections, and diabetes mellitus. This work presents the first report on the evaluation of the antioxidant and antimicrobial potential along with the phytochemical analysis of Rosa gallica var. aegyptiaca leaves. Five leaf extracts of hexane, chloroform, methanol, hydromethanol 80%, and water were prepared. Assessment of antioxidant activity was carried out via DPPH radical scavenging assay. Antimicrobial activity against five foodborne pathogenic bacteria—including Listeria monocytogenes, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Salmonella enteritidis—and the fungus Candida albicans, was examined using the disc diffusion method. Total phenolic content and total flavonoid content were determined using the Folin–Ciocalteu reagent and aluminum chloride methods, respectively. Isolation, identification, and quantification of phenolic compounds were performed using HPLC-DAD analysis. Amongst the five leaf extracts that were investigated, hydromethanol 80% extract possessed the highest extraction yield, antioxidant activity, total phenolic content, and antimicrobial activity against all tested microbial strains. Moreover, this extract furnished six active phenolic compounds: gallic acid (1), (+) catechin (2), chlorogenic acid (3), (–) epicatechin (4), quercetin-3-O-α-d-(glucopyranoside) (5), and quercetin (6). This study provides an alternative utilization of R. gallica var. aegyptiaca leaves as a readily accessible source of natural antioxidants and antimicrobials in the food and pharmaceutical industries.     

Phytochemical profiles,antioxidant and anti-acetylcholinesterasic activities of the leaf extracts of Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire in different solvents

In this work, the extracts obtained with different solvents from the leaves of Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire were studied for their phytochemical profile and then for their antioxidant and acetylcholinesterase inhibitory activities. The phytochemical profiles of the extracts in n-hexane, dichloromethane, ethyl acetate, methanol, anthraquinone rich and water, showed the presence of different compounds belonging to several classes of natural products such as flavonoids, anthraquinones, saccharides and fatty acids. For what concerns the biological tests, the ethyl acetate, methanol and anthraquinone rich extracts showed the highest activities in both assays due to the high amount of compounds possessing those properties such as flavonoids and anthraquinones. By consequence, these specific extracts of the species may be considered to be potential sources of natural antioxidant and anti-acetylcholinesterasic compounds.     

Phenolic and Volatile Composition and Antioxidant Properties of the Leaf Extract of Brassica fruticulosa subsp. fruticulosa (Brassicaceae) Growing Wild in Sicily (Italy)

In continuation of research conducted on species of the spontaneous flora of Sicily (Italy) belonging to the Brassicaceae family, Brassica fruticulosa subsp. fruticulosa was selected. It is an edible species utilized in Sicilian traditional medicine. In this study, for the first time, the phenolic and the volatile compounds and the antioxidant properties of the hydroalcoholic extract obtained from the leaves of B. fruticulosa subsp. fruticulosa were characterized. Through HPLC-PDA/ESI-MS analysis, a total of 22 polyphenolic compounds (20 flavonoids and 2 phenolic acids) were identified, with 3-hydroxiferuloylsophoroside-7-O-glucoside (1.30 mg/g ± 0.01) and kaempferol-3-O-feruloylsophoroside-7-O-glucoside (1.28 mg/g ± 0.01) as the most abundant compounds. Through SPME-GC/MS several volatiles belonging to different chemical classes were characterized, with nitriles and aldehydes accounting for more than 54% of the whole volatile fraction. The extract of B. fruticulosa subsp. fruticulosa showed moderate activity in the DPPH assay (IC₅₀ = 1.65 ± 0.08 mg/mL), weak reducing power (17.47 ± 0.65 ASE/mL), and good chelating properties (IC₅₀ = 0.38 ± 0.02 mg/mL), reaching approximately 90% activity at the highest tested concentration. Lastly, the extract was non-toxic against Artemia salina, indicating its potential safety. According to the findings, it can be stated that B. fruticulosa subsp. fruticulosa represents a new valuable source of bioactive compounds.     

Lupane triterpenoids,antioxidant potential and antimicrobial activity of Myrciaria floribunda (H. West ex Willd.) O. Berg.

Chemical composition of the methanol extract of Myrciaria floribunda leaves was investigated. The nor-lupane triterpenoids platanic acid and messagenic I acid were identified, along with other known triterpenoids (betulinic aldehyde, ursolic acid acetate and betulinic acid), a new lupane triterpenoid (2α,6α,30-trihydroxybetulinic acid) and the flavonoids catechin, quercetrin and mirycitrin. The structures were determined by spectroscopic methods (NMR, LC-MS, GC-MS). The major isolated compound was betulinic acid. The methanol extract and 2α,6α,30-trihydroxybetulinic acid were evaluated for their DPPH scavenging potential. The tested triterpenoid was one hundred times more active than betulinic acid, but less active than the extract. Screening for antimicrobial activity showed that the methanol extract was active against Staphylococcus aureus and Escherichia coli, but inactive against Candida albicans and Candida krusei, while 2α,6α,30-trihydroxybetulinic acid was inactive to all tested microorganisms.     

Isolation and characterization of flavonoids from the roots of medicinal plant Tadehagi triquetrum (L.) H.Ohashi

Abstract

Three flavonoid compounds were isolated from the roots of medicinal plant Tadehagi triquetrum (L.) H.Ohashi, also known as Desmodium triquetrum (Fabaceae). On the basis of the chemical and spectral analysis, the compounds were identified as baicalein (Flavone), naringin and neohesperidin (Flavonone). To the best of our knowledge and based on the literature survey all three compounds were first time reported from this medicinal plant.

     

Deoxypegan-1-one derivatives. synthesis and borohydride reduction of 3-[(E)-arylmethylidene]-3,9-dihydropyrrolo[2,1-b]quinazolin-1(2H)-ones

3-[(E)-Arylmethylidene]-3,9-dihydropyrrolo[2,1-b]quinazolin-1(2H)-ones were prepared by reaction of quinazolyl-2-propionic acid hydrochloride with aromatic aldehydes in acetic anhydride in the presence of Et₃N. 3-[(E)-Arylmethylidene]-1,2,3,9-tetrahydropyrrolo[2,1-b]quinazolin-1-ols were formed by reduction of the 3-arylidene derivatives with sodium borohydride in methanol, readily lost water when heated with acids, and were converted into 3-[(E)-arylmethylidene]-3,9-dihydropyrrolo[2,1-b]quinazolines. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 463–467, September–October, 2006.     

Synthesis and crystal structure of the pyridinium acid nitrate [(PyH)2(NO3)][H2(NO3)3] containing a dihydrogen trinitrate anion

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Syntheses and crystal structures of [(C6H5CH2C5H4)2GdCl.THF]2 and (C6H5CH2C5H4)2ErCl.THF

[(C₆H₅CH₂C₅H₄)₂GdCl.THF]₂ (1) and (C₆H₅CH₂C₅H₄)₂ErCl.THF (2) were prepared by the reaction of LnCl₃ (Ln? Gd, Er) with benzylcyclopentadienyl sodium in THF and characterized by elemental analysis, IR, ¹H NMR, ¹³C NMR, MS and thermal gravimetry. The crystal structures of both compounds were determined. Complex 1 is dimeric and its structure belongs to the monoclinic, P2₁/c space group with a=1.1432(2), b=1.2978(2), c=1.7604(3) nm, β=108.75(2), V=2.4732(9) nm³, Z=2(four monomers), D_c“1.54 g.cm^?3. R=0.0342 and R_w“0.0362. Complex 2 is monomer and its structure belongs to the orthorhombic, P2₁2₁2₁ space group with a=0.8645(2), b=1.1394(3), c=2.5289(4) nm, V=2.4919(9) nm³, Z=4, D_c“1.56 g.cm^?3. R=0.0514, R_w“0.0529. The determination of the crystal structure shows that in complex 1 the benzyl groups on the cyclopentadienyls coordinated to Gd³⁺ are located in the opposite direction (139°); in complex 2 the benzyl groups on the cyclopentadienyls coordinated to Er³⁺ are located in the same direction (6.5°).     

Crystal structure,Hirshfeld surface analysis,Thermal study and Conduction mechanism of [(C4H9)4P]3Bi2Cl9 compound

A novel tris (tetrabutylphosphonium) nonachlorodibismuthate (III) compound has been synthesized and characterized by a single‐crystal X‐ray diffraction, calorimetric, IR spectroscopy and electrical measurements. X‐ray diffraction analysis at room temperature reveals that the title compound belongs to the monoclinic system with P2₁/c space group. The unit cell dimensions are: a = 19.201(6) Å, b = 16.743 (5) Å, c = 22.396 (8) Å, β = 98.96 (2)° and Z = 4. The crystal structure was solved down to R equal to 0.035 for 5597 independent reflections. The crystal package is provided by electrostatic interactions and hydrogen bonds (C‐H ^…. Cl). Intermolecular interactions present in the grown single crystal were analyzed by Hirshfeld surface and 2‐dimensional fingerprint plot. The differential scanning calorimetry reveals one order–disorder phase transition at 400 ± 5 K.The electrical conductivity were carried out in the frequency range 200 Hz–1 MHz at various temperatures 343–413 K using impedance spectroscopy technique. The obtained results were analyzed by fitting the experimental data to an equivalent circuit model. The temperature dependence of alternating and direct current conductivities confirms the observed phase transition in the calorimetric study; they were described in terms of Arrhenius relation. AC conductivity measurements reveal that the conduction depends on both frequency and temperature, this agrees well with Correlated Barrier Hopping model in phase I and II.     

混合配体配合物[Cd2(phen)4(bmal)2]·3H2O的合成与晶体结构研究

A novel binucleus mixed-ligand[Cd₂(phen)₄(bmal)₂]·3H₂O (phen=phenanthroline; bmal=benzylmalonic acid radical) has been synthesized by the reaction of phen and bmal with cadmium(Ⅱ) salt. X-ray crystal structure analysis was carried out to determine the crystal structure of the title complex. The crystal of the title complex belongs to monoclinic system with space group P2₁/c, a=1.119 1(8) nm, b=2.480 5(17) nm, c=1.063 4(8) nm, β=142.042(12)°, Z=4, V=2.887(3) nm³, D_c=1.613 g·cm^-3, R₁=0.046 2, wR₂=0.115 6, F(000)=1 424. One carboxyl of bmal is coordinated to Cd(1) with monodentate form, the others are coordinated to Cd(2) with bidentate form. The complexes form a 1-D chain structure bridged by hydrogen bonds that formed by uncoordinated water and oxygen atom of carboxyl group in bmal, the 2-D network structure was formed by π-π interaction of neighbouring phen. CCDC: 257080.     

4-Hydroxy-2-quinolones. 108. N-R-amides of 9-fluoro-1-hydroxy-5-methyl-3-oxo-6,7-dihydro-3H,5H-pyrido[3,2,1-ij]quinoline-2-carboxylic acid and their antitubercular activity

The reaction of 6-fluoro-2-methyl-1,2,3,4-tetrahydroquinoline with triethylmethanetricarboxylate gives di(9-fluoro-1-hydroxy-5-methyl-3-oxo-6,7-dihydro-3H,5H-pyrido[3,2,1-ij]quinolin-2-yl)methane and ethyl 9-fluoro-1-hydroxy-5-methyl-3-oxo-6,7-dihydro-3H,5H-pyrido[3,2,1-ij]quinoline-2-carboxylate from which alkyl-, dialkylaminoalkyl-, and hetarylamides as well as hydrazides were prepared. The structure and antitubercular properties of the compounds synthesized are discussed. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1391–1407, September, 2006.     

Replacement of Trimethylamine in Trimethylamine‐trispentafluoroethyl‐borane. Structures of [(C2F5)3BNMe3], [NMe4][(C2F5)3BOH], and K[(C2F5)3BCH2(CO)C6H5]

Trimethylamine‐tris(pentafluoroethyl)borane [(C₂F₅)₃BNMe₃] ( 1 ) reacts at 190 °C with water under displacement of the trimethylamine ligand to yield the hydroxy‐tris(pentafluoroethyl)borate [(C₂F₅)₃BOH]^? ( 2 ). In tributylamine 1 reacts with alkynes HC≡CR to form novel ethynyl‐tris(pentafluoroethyl)borate anions [(C₂F₅)₃BC≡CR]^? – R = C₆H₅ ( 3 ), C₆H₄CH₃ ( 4 ), Si(CH(CH₃)₂)₃ ( 5 ) – in moderate yields. Compound 3 adds water across the triple bond to form the novel anion [(C₂F₅)₃BCH₂(CO)C₆H₅]^? ( 6 ). The structures of [(C₂F₅)₃BNMe₃], [NMe₄][(C₂F₅)₃BOH] and K[(C₂F₅)₃BCH₂(CO)C₆H₅] have been determined by x‐ray crystallography.     

Synthesis of polyesters as binders for deinkable inks. VI. Structural analysis of the copolyesterification between o-phthalic anhydride,oleic acid,and trimethylolpropane in bulk at 160°C by high resolution 13C- and 1H nuclear magnetic resonance (13C- and 1H-NMR)

A detailed structural analysis of the copolyesterification in bulk without any external catalyst at 160°C between o-phthalic anhydride (P), oleic acid (O), and trimethylolpropane (T) with a mol ratio ([ COOH]/[ OH]) = 0.70 has been carried out by high resolution ¹³C nuclear magnetic resonance (¹³C-NMR) (DMSO-d₆ and CDCl₃ solutions), ¹H nuclear magnetic resonance (¹H-NMR) (CDCl₃ solution), and by volumetry. The use of CDCl₃ as NMR solvent has allow us to identify several signals that have been assigned to trimethylolpropane monoesters with different esterification degrees in the o-phthalate residue. Identically, we have detected signals assignable to monoesters at the chain ends in structures with different chain lengths. These monoesterified structures have been also confirmed by analyzing samples modified by the diazomethane addition. These modified samples have been also used to determine free acid groups as their methoxylic derivatives by ¹H-NMR in CDCl₃ solution. We have not observed any detectable signs of gelation nor products produced by secondary reactions. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 3409–3429, 1997