Activity Of Phenolic Compounds Research Articles

Gut microbiota and health: connecting actors across the metabolic system.

Overweight-related metabolic diseases are an important threat to health in the Western world. Dietary habits are one of the main causative factors for metabolic syndrome, CVD and type 2 diabetes. The human gut microbiota is emerging as an important player in the interaction between diet and metabolic health. Gut microbial communities contribute to human metabolism through fermentation of dietary fibre and the result of intestinal saccharolytic fermentation is production of SCFA. Acetate, propionate and butyrate positively influence satiety, endocrine system, glucose homeostasis, adipogenesis, lipid oxidation, thermoregulation, hepatic gluconeogenesis, endothelial function and gut barrier integrity, and these mechanisms have all been linked to protection from type 2 diabetes, hypertension and cardiovascular health. The gut microbiota is also involved in bile acid metabolism and regulating their cell signalling potential, which has also been shown to modify pathways involved in metabolic health. Similarly, the gut microbiota renders recalcitrant plant polyphenols into biologically active small phenolic compounds which then act systemically to reduce metabolic disease risk. This review summarises how dietary patterns, specific foods and a healthy lifestyle may modulate metabolic health through the gut microbiota and their molecular cross-talk with the host.

Hypoglycemic activity of Capparis ovata desf. var. palaestina zoh. methanol extract

Caper (Capparis ovata Desf. and Capparis spinosa L.) is naturally widespread in Turkey. Traditionally, buds, fruits, seeds and roots of this plant are used as tonic, diuretic, anti-rheumatic, expectorant, antidiabetic, and antifungal. The aim of this study is to evaluate potential hypoglycemic effect of C. ovata var. palaestina extracts in alloxan-induced diabetic mice. For this purpose; diabetic mice were administered with 100, 300, 500 mg/kg (i.p.) doses of methanol extract of bud and fruit. Blood glucose levels were screened 60, 120, 240 and 360 min. after treatment. Furthermore, high resolution mass spectrometry (HRMS) analysis, ABTS and DPPH free radical scavenging activity test, and phenolic and flavonoid compounds analysis of extracts were carried out. The data obtained from in vivo study revealed that fruit-methanol 500 mg/kg (FM3), bud-methanol 300 mg/kg (BM2), bud-methanol 500 mg/kg (BM3) extracts showed significant hypoglycemic activity. All extracts indicated significant antioxidant activity, however bud-methanol (BM) extract demonstrated the most potent antioxidant activity. Moreover high levels of phenolic substances and flavonoids were involved in all extracts, but the highest levels were found in FM extract. HRMS study showed that rutin, quercetin 3-O-glucoside (isoquercitrin) and stachydrine substances had seen in BM extract. The results of this study showed that the C. ovata var. palaestina extracts which, indicate hypoglycemic, antioxidant activities, might provide additional support in diabetes.

Extraction, Purification, and Hydrolysis Behavior of Apigenin-7-O-Glucoside from Chrysanthemum Morifolium Tea.

Apigenin-7-O-glucoside is an active phenolic compound in Asteraceae flowers and possesses remarkable therapeutic applications. However, its high price and low abundance in plants limit its use, meanwhile it would hydrolyze in the purification process. In this study, apigenin-7-O-glucoside extracted with ultrasound and purified with preparative HPLC from Chrysanthemum morifolium ‘Huangju’ was investigated, as well as its hydrolysis behavior and bioactivities. The optimized extraction conditions were: solid/liquid ratio: 1:20, extraction time: 35 min, temperature: 50 °C, and ultrasound power: 350 W. The content of apigenin-7-O-glucoside was up to 16.04 mg/g. Apigenin-7-O-glucoside was then purified with preparative HPLC from the extract, and confirmed by Q-TOF/MS. Apigenin-7-O-glucoside was partially hydrolyzed in acidic condition, and the hydrolysis rate depended on the pH value and temperature. The antioxidant activity increased as a result of the hydrolysis process. This study provided a green and effective way to obtain apigenin-7-O-glucoside and would be beneficial for further investigations into nutritional and functional aspects apigenin-7-O-glucoside and other glycosides.

SOLVENT AND TECHNIQUES EXTRACTION INFLUENCE ON PHYTOCHEMICAL PROFILE AND FREE RADICALS INHIBITION OF PHEONIX DACTYLIFERA L

The main of this investigation was to compare the extraction efficiency of different methods with various solvents from Phoenix dactylifera L extracts. The antioxidant activity and total phenolic compounds of extracts were evaluated using the various method. The highest extraction yield was founded in 70% methanol. Acetone extract exhibited a higher total antioxidant activity, ferric reducing antioxidant power and DPPH radical scavenging activity. The same extract also exhibited the highest phenolic, flavonoid, flavanol and condensed tannins contents. The results revealed that the ultrasonic is most suitable for the extraction of phenolic compounds and thus showing high levels of phenolic content and very high antioxidant capacities relative to the soxhlet and maceration technique. The results propose that Phoenix dactylifera L leaves extract can be considered as a rich source of natural bioactive compounds.

Biologically active phenolic acids produced by Aspergillus sp., an endophyte of Moringa oleifera

This study investigates the secondary metabolites of an endophytic Aspergillus sp. isolated from leaves of M. oleifera growing in Anambra State, South-Eastern Nigeria. Antimicrobial and antioxidant screening of the fungal extract and isolated compounds, as well as cytotoxicity assay of the extract against cisplatin-sensitive A2780 (sens) and cisplatin-resistant A2780 (cisR) ovarian cancer cell lines were carried out using standard methods. Chemical investigations of the fungal extract involving a combination of different chromato-graphic methods and spectroscopic techniques were carried out to isolate and characterize the constituents of the extract. At a concentration range of 1-4 mg/ml, the crude extract of Aspergillus sp. showed mild antimicrobial activity against Bacillus subtilis, Klebsiella pneumoniae, and Candida albicans. The fungal extract showed good antioxidant activity at 500 µg/ml, with an inhibition of 72.1%. Also, at 100 µg/ml, the extract showed excellent cytotoxic activity against A2780 (sens) and A2780 (cisR), with growth inhibitions of 105.1% and 105.5% respectively. Two known pharmacologically active phenolic compounds (p-hydroxyphenyl acetic acid and ferulic acid) were isolated from the fermentation extract of the endophytic fungus. At 250 µg/ml, ferulic acid exhibited an excellent antioxidant activity with an inhibition of 90.4%, while an inhibition of 35.4% was recorded for p-hydroxyphenyl acetic acid. Ferulic acid also showed a mild antifungal activity at 500 µg/ml against A. niger with an IZD of 2 mm. p-Hydroxyphenyl acetic acid showed no antimicrobial activity. These results further confirm the potentials of endophytic fungi associated with Nigerian plants as source of bioactive compounds with pharmaceutical or industrial applications. DOI: http://dx.doi.org/10.5281/zenodo.1404981

The role of guaiacyl moiety in free radical scavenging by 3,5-dihydroxy-4-methoxybenzyl alcohol: thermodynamics of 3H+/3e− mechanisms

ABSTRACTParticipation of guaiacyl moiety of 3,5-dihydroxy-4-methoxybenzyl alcohol (DHMBA) in inactivation of free radicals was investigated using the DFT method. The thermodynamics of triple (3H+/3e−) free radical scavenging mechanisms was investigated. The Gibbs free energies of reactions of inactivation of selected 10 free radicals indicate DHMBA as a potent scavenger. Obtained results allow us to suggest that the contribution of guaiacyl moiety to antioxidant activity of phenolic compounds should be taken into account, what has been scarcely considered until now.

Biochemical composition and antioxidant activity affected by spraying potassium sulfate in black grape (Vitis vinifera L. cv. Rasha).

The physiological and metabolic processes involved with grapevine growth and production are influenced by key macro- and micronutrients. Potassium is an essential plant nutrient that affects growth and fruit quality. In this study, the impact of foliar spraying of potassium sulfate (K2 SO4 ) on qualitative characteristics of grape berries was evaluated in the cultivar 'Rasha', a commonly cultivated cultivar in Kurdistan province of Iran. Leaves of the fully grown vines were sprayed with each of the 1.5 and 3 g L-1 K2 SO4 solutions once (1 month after petal senescence) and twice (15 days after first spraying). The control plants were sprayed with distilled water. Various biochemical contents and enzyme activities on the ripe berries were analyzed. Significant increases in anthocyanin, total protein content, and antioxidant enzyme activities were observed in the berries treated twice with 3 g L-1 K2 SO4 . Concentrations of total carbohydrate, phenol, and antioxidant activity in berries sprayed with K2 SO4 were higher than in the controls. We observed a strong correlation between antioxidant activity and different phenolic compounds. These findings suggest that K2 SO4 treatment influences biosynthesis of phenolic compounds and antioxidant enzymes. Thus, treatment by K2 SO4 could improve nutritional and qualitative attributes of grape. © 2018 Society of Chemical Industry.

Green synthesis of gold and silver nanoparticles from Cannabis sativa (industrial hemp) and their capacity for biofilm inhibition.

BackgroundCannabis sativa (hemp) is a source of various biologically active compounds, for instance, cannabinoids, terpenes and phenolic compounds, which exhibit antibacterial, antifungal, anti-inflammatory and anticancer properties. With the purpose of expanding the auxiliary application of C. sativa in the field of bio-nanotechnology, we explored the plant for green and efficient synthesis of gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs).Methods and resultsThe nanoparticles were synthesized by utilizing an aqueous extract of C. sativa stem separated into two different fractions (cortex and core [xylem part]) without any additional reducing, stabilizing and capping agents. In the synthesis of AuNPs using the cortex enriched in bast fibers, fiber-AuNPs (F-AuNPs) were achieved. When using the core part of the stem, which is enriched with phenolic compounds such as alkaloids and cannabinoids, core-AuNPs (C-AuNPs) and core-AgNPs (C-AgNPs) were formed. Synthesized nanoparticles were character-ized by UV–visible analysis, transmission electron microscopy, atomic force microscopy, dynamic light scattering, Fourier transform infrared, and matrix-assisted laser desorption/ionization time-of-flight. In addition, the stable nature of nanoparticles has been shown by thermogravimetric analysis and inductively coupled plasma mass spectrometry (ICP-MS). Finally, the AgNPs were explored for the inhibition of Pseudomonas aeruginosa and Escherichia coli biofilms.ConclusionThe synthesized nanoparticles were crystalline with an average diameter between 12 and 18 nm for F-AuNPs and C-AuNPs and in the range of 20–40 nm for C-AgNPs. ICP-MS analysis revealed concentrations of synthesized nanoparticles as 0.7, 4.5 and 3.6 mg/mL for F-AuNPs, C-AuNPs and C-AgNPs, respectively. Fourier transform infrared spectroscopy revealed the presence of flavonoids, cannabinoids, terpenes and phenols on the nanoparticle surface, which could be responsible for reducing the salts to nanoparticles and further stabilizing them. In addition, the stable nature of synthesized nanoparticles has been shown by thermogravimetric analysis and ICP-MS. Finally, the AgNPs were explored for the inhibition of P. aeruginosa and E. coli biofilms. The nanoparticles exhibited minimum inhibitory concentration values of 6.25 and 5 µg/mL and minimum bactericidal concentration values of 12.5 and 25 µg/mL against P. aeruginosa and E. coli, respectively.

Bioactivity and application of plant seeds’ extracts to fight resistant strains of Staphylococcus aureus

Staphylococcus aureus is a highly dangerous pathogen that causes lots of health problems. The resistant strains to methicillin (MRSA) are dangerously health threatens. Nine plant seeds’ extracts (Alium ampeloprasum, Allium cepa, Brassica juncea, Lycium shawii, Nigella sativa, Ocimum basilicum, Peganum harmala, Phyllanthus emblica and Portulaca oleracea) were evaluated as microbial inhibitor agents against S. aureus isolates, including MRSA strains. The crude extracts of L. shawii and P. emblica seeds proved to be the most active antimicrobials, against the entire S. aureus strains, using both quality and quantity assays for their bactericidal activity. Both L. shawii and P. emblica seeds contained remarkable amounts from active phytochemicals, alkaloids, phenolic compounds, tannins and flavonoids. P. emblica seeds were exceedingly rich sources of phenolic compound and flavonoids. The electron scanning micrographs of S. aureus cells, after exposure to plant seeds’ extracts, showed that bacterial cells were shrunk and became tiny, diminutive and dehydrated after 3 h and the entire cells were fully lysed, exploded or disrupted after 6 h of exposure to P. emblica extract; whereas exposure to L. shawii extract derived treated cells to lyse and combine with each other’s after 3 h then complete cell wall lysis was observed after 6 h of exposure. The applications of plant seeds’ extracts, for textile finishing and ointment formulation, confirmed their efficacy as potent applicable anti-MRSA agents. It may be recommended to apply plant seeds’ extract, e.g. P. emblica and L. shawii, as powerful antibacterial agents for the control of the skin and foodborne pathogenic bacteria, S. aureus, and their resistant MRSA strains.

Reconstruction of tyrosol synthetic pathways in Escherichia coli

Tyrosol is a pharmacologically active phenolic compound widely used in the medicine and chemical industries. Traditional methods of plant extraction are complicated and chemical synthesis of tyrosol is not commercially viable. In this study, a recombinant Escherichia coli strain was constructed by overexpressing the phenylpyruvate decarboxylase ARO10 from Saccharomyces cerevisiae, which could produce tyrosol from glucose. Furthermore, genes encoding key enzymes from the competing phenylalanine and tyrosine synthesis pathways and the repression protein TyrR were eliminated, and the resulting engineered strain generated 3.57 mmol·L− 1 tyrosol from glucose. More significantly, codon optimization of ARO10 increased expression and tyrosol titer. Using the novel engineered strain expressing codon-optimized AR10 in shake-flask culture, 8.72 mmol·L− 1 tyrosol was obtained after 48 h. Optimization of the induction conditions improved tyrosol production to 9.53 mmol·L− 1 (1316.3 mg·L− 1). A higher titer of tyrosol was achieved by reconstruction of tyrosol synthetic pathway in E. coli.

Encapsulation of biological active phenolic compounds extracted from wine wastes in alginate-chitosan microbeads

Grapes (Vitis vinifera) are produced in large amounts worldwide and mostly are used for winemaking. Their untreated wastes are rich in valuable secondary metabolites, such as phenolics. Thus, in this study, white and red wine wastes (Malagouzia and Syrah variety) were investigated for their added value phenolics, which were analysed by high performance liquid chromatography (HPLC) and electrospray ionisation-mass spectrometry (ESI/MS) and subsequently encapsulated in several polymers. Extracts from all wastes gave high amounts of total phenolics (13 ± 2.72–22 ± 2.69 mg g−1) and possessed high antioxidant activity (67–97%). In addition to their significant antibacterial activity against gram-negative and gram-positive bacteria, interesting results were also obtained from their anti-inflammatory and antiplatelet activity, in vitro. Encapsulation of the extracts was selective, leaving out most of sugars and other organic compounds when alginate-chitosan was used. Encapsulation efficiency recorded for all extracts ranged from 55% to 79%. Release studies were also performed in several solutions aiming in their commercial use in food and pharmaceutical industries.

Nitric oxide inhibitory and anti-Bacillus activity of phenolic compounds and plant extracts from Mesua species

Species from the genus Mesua, Calophyllaceae, are rich source for phenolic compounds such as coumarin xanthone, and benzophenone derivatives. An investigation on the potential biologically active phenolic compounds 1–5 and crude extracts from the stem bark of Mesua hexapetala (Hook. f.) P.S. Ashton and Mesua beccariana (Baill.) Kosterm. for nitric oxide inhibitory activity on RAW 264.7 macrophage as well as anti-Bacillus activity on selected Bacillus were carried out. Hexapetarin (1), which we reported as a new compound isolated from M. hexapetala showed very good nitric oxide inhibitory activity with an IC50 value of 30.79±2.68μM. This compound also gave very significant activities towards Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 33019, Bacillus megaterium ATCC 14581 and Bacillus pumilus ATCC 14884 in disc diffusion and minimum inhibitory concentrations assay. Moreover, 1,3,7-trihydroxy-2,4-di (3-methyl-2-butenyl)xanthone (2) isolated from M. hexapetala showed very significant nitric oxide inhibitory activity with an IC50 value of 12.41±0.89μM and does not exhibit anti-Bacillus activity on four types of Bacillus. Meanwhile, compounds 3–5 were inactive in the nitric oxide activity test and anti-Bacillus assay.

Assessment of phenolic profile and antioxidant power of five pistachio (Pistacia vera) cultivars collected from four geographical regions of Iran.

In this study, the levels and antioxidant activities of some secondary metabolites isolated from five pistachio (Pistacia vera) cultivars collected from four different geographical regions of Iran, were studied. Total phenolic compounds levels were determined by Folin-Ciocalteu method. Total flavonoid content was determined as AlCl3 complex and expressed as mg of quercetin equivalents (QE)/g dry extract and total proantocyanidins content was expressed as mg of catechin equivalents (CA)/g dry extract. In order to evaluated the antioxidant activity of the compounds, DPPH and FRAP assays were used. The highest level of total phenols (156.42 mg GA/g DE), total flavonoids (130.94 mg QE/g DE) and total proantocyanidins (152.816 mg CA/g DE) were obtained in Akbari cultivar from Rafsanjan, followed by Badami-e-sefid and Ahmad aghaei. The lowest amount of total phenolic content (TPC), total flavonoid content (TFC) and total proanthocyanidin content (TPrAC) were found in Badami-e-sefid from Feizabad (128.140 mg GA/g DE, 93.176 mg QE/g DE and 118.870 mg CA/g DE, respectively). Also, a positive correlation (r2=0.9834) was found between antioxidant activity and total phenolic compounds. Pistachio increased their phytochemical compounds to contrast with abiotic stress. Our data could be useful for introducing special characteristics to the plants, and can be considered when planning a new breeding program or choosing a specific cultivar for a particular use.

Chromatographie Sur Couche Mince Et Activité Antiradicalaire D’extraits De Pupalia Lappacea (L.) Juss. Amaranthaceae

Introduction: P. lappacea is a plant used in traditional medicine, in the regions of Niamey and Tillaberi, as anti-hemorrhoids. It contains tannins, sterols, triterpenes, saponosides, mucilages, anthracene derivatives, oses and holosides for which it is necessary to appreciate the activities relating to the medicinal virtues. Objective: To contribute to the phytochemical and pharmacological study of Pupalia lappacea, through the semi-quantitative estimation of phytocomposés and the research of the antiradical power of its various extracts. Methodology: Phytochemical screening, semiquantitative estimation and a study of the antioxidant activity of phytocomposites were carried out by thin layer chromatography (TLC) from extracts obtained with increasing polarity solvents. Results: All P. lappacea extracts contain a large number of bioactive chemical compounds. Substances with antihaemorrhoidal activity (phenolic compounds, tannins) are found mainly in the aqueous extracts (digested, decoct exhausted) and the methanolic extract. The strongest antiradical activity observed with the digest and the spent decoction after migration in the solvent system. Ethyl acetate - Methyl ethyl ketone - Formic acid - Water (5-3-1-1) would be linked to phenolic compounds. A less severe free radical activity, probably due to terpenic substances, was observed with the BAW solvent system (60-15-25). The extract corresponding to the traditional (decocted) use of P. lappacea also has low antioxidant activity. Conclusion: The use of P. lappacea as antihemorrhoid is justified. However, the digest and the spent decoction would have greater anti-hemorrhoidal properties than those of the decoction obtained by the traditional method. An assay of the phenolic compounds, tannins, terpenic compounds, in the infused, the decoction, the digested and the exhausted decoction would make it possible to choose the best method of extraction and to improve the anti-hemorrhoidal effect of the P. lappacea based medicinal preparations.

Phenolic Profile, Mineral Content and Antibacterial Activity of the Methanol Extract of Vaccinium myrtillus L.

Bilberry is considered as one of the most economically important wild berries. However, bilberry is not enough investigated, and there are only a few published works. Therefore, we performed in one place complete qualitative analysis, antimicrobial activity against different Gram-positive and Gram-negative bacteria and contents of metals. In our research, it was found that bilberry contains different active phenolic compounds, such as chlorogenic acid, delphinidin glycoside, delphinidin arabinoside, cyanidin glycoside, cyanidin arabinoside, malvidin glycoside, peonidin glycoside, and malvidin arabinoside. The content of metals was different in leaves and fruits. In our samples, the content of aluminum, boron, barium, calcium, cadmium, chromium, copper, iron, manganese, nickel, phosphorus, silicon and zinc was higher, and contents of potassium, magnesium, and sodium were lower than in bilberry samples investigated in Latvia. Antimicrobial activity of investigated extracts was evaluated against laboratory control strains from ATCC collection, Gram (+) bacteria: Staphylococcus epidermidis ATCC 12228, Staphylococcus aureus ATCC 6538, Streptococcus pyogenes ATCC 19615, Enterococcus faecalis ATCC 19433, Propionibacterium acnae ATCC 11827, and Gram (-) bacteria: Escherichia coli ATCC 9863, Pseudomonas aeruginosa ATCC 9027, Acinetobacter boumanii ATCC 196060, Proteus mirabilis ATCC 12453, Klebsiella pneumonia ATCC 10031, and against related strains isolated from human wound swabs. V. myrtillus extract was less potent against strains from wounds compared to ATCC strains as well Gram (-) bacteria compared to Gram (+) bacteria. The most sensitive strains were St. epidermidis, St. pyogenes, P. mirabilis and S. aureus.

METHYL GALLATE FROM JIRINGA (ARCHIDENDRON JIRINGA) AND ANTIOXIDANT ACTIVITY.

Objective: This research was study about phytochemical active phenolic compound from pods of jiringa (Archidendron jiringa (Jack) I. C. Nielsen) and it’s antioxidant.Methods: Pods of jiringa were air dried and macerated with methanol. Extract was evaporated using rotary evaporator, and then, crude extract dissolved with water and partitioned with ethyl acetate. Extracts were evaporated and partitioned again with methanol and n-hexane. Column and preparative chromatography used to separate pure compound. Pure compound as methyl gallate was identificated with data from nuclear magnetic resonances of proton H (1H NMR), NMR of carbon (13C NMR), and mass spectrometry (MS). Antioxidant activity of pure compound tested by 1,1-diphenyl-2-picrylhydrazyl method.Results: We found pure phenolic compound from pods of jiringa as methyl gallate that exists on fraction III-2, and it has high antioxidant activity with inhibition concentration 50 was 3.7576 μg/ml.Conclusions: Pods of jiringa contain of active phenolic compound as methyl gallate that has high antioxidant activity. Therefore, it can be used as a source of natural antioxidant.

METHYL GALLATE FROM JIRINGA (ARCHIDENDRON JIRINGA) AND ANTIOXIDANT ACTIVITY.

Objective: This research was study about phytochemical active phenolic compound from pods of jiringa (Archidendron jiringa (Jack) I. C. Nielsen) and it’s antioxidant.Methods: Pods of jiringa were air dried and macerated with methanol. Extract was evaporated using rotary evaporator, and then, crude extract dissolved with water and partitioned with ethyl acetate. Extracts were evaporated and partitioned again with methanol and n-hexane. Column and preparative chromatography used to separate pure compound. Pure compound as methyl gallate was identificated with data from nuclear magnetic resonances of proton H (1H NMR), NMR of carbon (13C NMR), and mass spectrometry (MS). Antioxidant activity of pure compound tested by 1,1-diphenyl-2-picrylhydrazyl method.Results: We found pure phenolic compound from pods of jiringa as methyl gallate that exists on fraction III-2, and it has high antioxidant activity with inhibition concentration 50 was 3.7576 μg/ml.Conclusions: Pods of jiringa contain of active phenolic compound as methyl gallate that has high antioxidant activity. Therefore, it can be used as a source of natural antioxidant.

Isolation of Cinnamic Acid Derivatives from the Bulbs of Allium tripedale.

Background:Allium genus with 750 species is the most diverse genus in the Amaryllidaceae family. Historically, Allium species have been used as medicinal plants, especially for prevention and treatment of cardiovascular diseases and considered as valuable sources of phytonutrients. Phytochemical investigation of Allium tripedale, locally called “Anashq,” which is an edible plant of the “Zagros” region (west of Iran) was conducted in the present study.Materials and Methods:Air-dried bulbs of the plant were extracted in a four-step extraction method with increasing polarity using hexane, chloroform, chloroform–methanol (9:1), and methanol. Chloroform-methanol (9:1) extract was fractionated by medium-pressure liquid chromatography on a RP-18 column using a linear gradient solvent system of H2O to MeOH. Phenolic-rich fractions were subjected to the final isolation and purification of the constituents by reversed-phase high-performance liquid chromatography method. Structure elucidation of the compounds was performed through comprehensive methods including 1D-and 2D-NMR and mass spectroscopy.Results:Two cinnamic acid derivatives were isolated from the bulbs of A. tripedale; using spectroscopic methods, their chemical structures were determined as 6,7-dimethoxy N-trans-caffeoyltyramine (1) and N-trans-feruloyltyramine (2).Conclusion:Cinnamic acid derivatives are pharmacologically active phenolic compounds, which have been isolated from different Allium species. Isolation of these compounds from A. tripedale is reported for the first time in this study and could be used as a chemical basis for explanation of the plant biological and pharmacological activities.

Responses of radish (Raphanus sativus) to drought stress

AbstractWith this study the effects of water deficit on radish growth, dry mass production and partitioning, source–sink relations, physiological responses and accumulation of secondary metabolites in storage roots and leaves have been investigated. Three water stress treatments were applied: (Control) 100% of water holding capacity (WHC), (WS50) 50% of WHC, (WS30) 30% of WHC. Water stress was effectively acquired starting from 287 growing degree days (GDD) as demonstrated by the lower values of relative water content (RWC), higher leaf temperature and NIR‐based water indices values in water stressed conditions. Water stress reduced storage root dry weight by 27% at WS50 and 53% at WS30 as well as leaf dry matter accumulation (by 23% and 31% in WS50 and WS30, respectively), expansion (by 28% and 45% in WS50 and WS30, respectively) and specific leaf area (by 7% and 20% in WS50 and WS30, respectively) at 403 GDD. The increasing of leaf‐to‐root mass (L/R) and leaf area‐to‐root mass (LA/R) ratios indicated less dry matter allocation into storage organs under water stress conditions. Besides, water shortage increased leaf greenness as estimated by the higher soil–plant analysis development (SPAD) values (+14% and +20% on average for WS50 and WS30, respectively); other reflectance indices only partially confirmed SPAD readings. Substantially, water limitation did not significantly influence total anthocyanin content, ABTS‐radical scavenging activity and total free phenolic compounds in storage roots, as well as the total free phenolic compounds in leaves. Radish showed a strong plasticity in its adaptation to drought thanks to avoidance mechanisms such as constrained leaf development, increased leaf thickness and adjusted source–sink relationships.

ANTIOXIDANT POTENTIALS AND SIMULTANEOUS ESTIMATION OF QUERCETIN, RUTIN, AND GALLIC ACID IN CURCUMA SPECIES

Objective: This study was designed to provide simple and cost-effective methods to quantify the biologically active phenolic compounds such as rutin, quercetin, and gallic acid from Curcuma species and evaluation of the antioxidant potentials of different parts with different solvent extracts of Curcuma species.Methods: Ultraviolet-visible spectrophotometer was used for the analysis of quercetin, rutin, gallic acid and total flavonoid content of Curcuma species extracts. Antioxidant potentials of Curcuma species extracts were evaluated using 2-2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity.Results: Ethyl acetate extract of Curcuma aromatica rhizome, aerial part contain higher quantity of quercetin and rutin compared to the other extracts, and also Curcuma species such as Curcuma longa and Curcuma amada contains high antioxidant capacity. The total flavonoid content was high in ethyl acetate extract of Curcuma aromatica as 88.35±0.25 μg/g dry weight of quercetin equivalents.Conclusion: Different extracts of Curcuma species possess good free radical scavenging activity and the IC50 of Curcuma amada aerial part, Curcuma longa aerial part, and Curcuma aromatica rhizome was 61.65±1.75, 62.95±1.85, and 89.40±0.15 (μg/ml), respectively. The Curcuma species contains high total phenolic compounds and antioxidant potentials.