Quantification Of Total Phenols Research Articles

Phenolics content and antioxidant activity of three Sorbus species

The phenolic content and antioxidant activity of Sorbus aucuparia L., Sorbus aria (L.) Crantz and Sorbus austriaca (Beck) Hedlund leaves and fruit were investigated. The quantification of total phenolics, flavonoids and phenolic acids was performed using the Folin–Ciocalteu, Dowd and Arnow methods, respectively. The antioxidant activity of the extracts was evaluated using DPPH, TEAC and FRAP methods with Trolox as a standard. Leaves had a higher content of phenolic compounds and antioxidant activity than the fruits for all species. The highest content of phenolics (76.11 mg gallic acid equivalents (GAE)/g plant), flavonoids (15.86 mg rutin equivalents (RE)/g plant) and phenolic acids (44.54 mg caffeic acid equivalents (CAE)/g plant) was determined for S. austriaca leaves. Sorbus austriaca fruit had the highest content of phenolics (13.21 mg GAE/g plant), flavonoids (1.82 mg RE/g plant) and S. aucuparia fruit had the highest content of phenolic acids (9.05 mg CAE/g plant). The antioxidant activity was in the range: DPPH=38.42–274.52 μmol Trolox equivalents (TE)/g plant; TEAC=43.23–403.02 μmol TE/g plant; FRAP=47.13–706.96 μmol TE/g plant. The highest values of antioxidant activity were found for S. austriaca leaf and fruit extracts while the lowest values were determined for S. aucuparia leaves and S. aria fruit. The antioxidant activity was highly correlated with total phenolics and phenolic acids.

Antioxidant activity and quantification of phenols, flavonoids and total tannins of Cinnamomum triplinerve (Lauraceae)

The present study evaluated the antioxidant activity and determined the total phenolic, flavonoid and tannin contents of the extracts from leaves, barks and fruits of Cinnamomum triplinerve. The antioxidant activity was evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) free radical scavenging method and the quantification of total phenols, flavonoids and tannins by spectrophotometry in the visible region. The extract from the barks was the most active in relation to the antioxidant activity (IC50 11.42 ± 0.41 μg/mL) and also the one with the highest total phenol content (36.38 ± 1.11 mg EAG/g extract) and total tannins, 14.58 ± 1.48 mg EAT/g extract. The results suggest that the antioxidant activity of C. triplinerve is mainly related to the presence of phenolic compounds, such as flavonoids and tannins, which are included in the category of free radical scavengers and efficient in the prevention of oxidative processes.

Anti-angiogenic Activity of Major Phenolics in Tamarind Assessed with Molecular Docking Study on VEGF Kinase Proteins.

The waste products of the tamarind canning industry have been discarded; however, it has potential health benefits. Herein, the study was carried out HPLC profiling of phenolic constituents of Tamarindis indica pericarp and seeds. Furthermore, the cytotoxic activity against HUH-7 cells was evaluated and assessed with molecular docking study on angiogenesis-related VEGF kinase proteins in addition to evaluating the level of released VEGF in treated HUH-7 cells by ELISA. Folin-ciocalteu and AlCl3 assays were used for quantification of total phenolics (TPC) and total flavonoids (TFC) contents, respectively. Molecular docking study was done on VEGF kinase proteins. TPC and TFC of pericarp and seeds were 0.35±0.02 g GAE g-1 DE and 0.12±0.009 g CE g-1 DE, 0.39±0.01 g GAE g-1 DE and 0.03±0.006 g CE g-1 DE, respectively. In pericarp, 8 phenolics were tentatively identified, where (+)-catechin was the major (27,386.04 μg g-1 DE) followed by gallic acid and naringenin (931.47, 500.42 μg g-1 DE) respectively. While in seeds, 11 phenolics were tentatively identified, where naringenin was the major (95,305.47 μg g-1 DE) followed by (+)-catechin and rutin (54,930.29, 15,361.66 μg g-1 DE) respectively. Aqueous and methanol seeds extracts exhibit cytotoxic effect with IC50 27.4±1.81 and 13.4±0.94 μg mL-1, respectively, it was more potent than aqueous and methanol pericarp extracts which had IC50 132±5.82 and 61.6±3.16 μg mL-1. The tested phenolics were fit on the active sites of VEGF kinase targets with varied degree of interactions. The cytotoxic and anti-angiogenic activities were confirmed in light of phenolics docking interactions. Results demonstrate for the first time that phenolics could inhibit angiogenesis via inhibiting kinase proteins, which could therefore be developed as antiangiogenic drugs.

TOTAL PHENOLICS AND FLAVONOIDS DETERMINATION AND ANTIOXIDANT CAPACITY EVALUATION OF Poincianella bracteosa (FABACEAE) EXTRACTS

Popularly known as “catingueira”, Poincianella Bracteosa is widely used by communities in the vicinity of the municipality of Tanhaçu, in Bahia to combat cough and bronchitis, therefore, based on data from a survey was performed ethnobotanical Phytochemical prospecting of the ethanolic extract obtained from aerial parts of poincianella Bracteosa, as well as the determination of antioxidant capacity and the levels of total phenolics and flavonoids present in the ethanolic extract and fractions. The study involved the obtaining of the ethanolic extract of the aerial parts of the species under study, by percolation with a 70% solution hidroetanólica. The fractionation of the ethanolic extract was performed with three different solvent (hexane, dichloromethane and ethyl acetate). The preliminary analysis of chemical composition was made by in vitro tests, with specific reagents for the different classes of secondary metabolites. The quantification of phenolics and total flavonoids was made by methods espectrofotométricos in the region of visible. The assessment of antioxidant capacity was performed by the method of kidnapping of free radicals DPPH and by method of reduction of iron ions (FRAP). The results of chemical prospecting demonstrated the presence of flavonoids, glycosides, gums and mucilage, heterosídeos antociânicos and condensed tannins in the ethanolic extract, being confirmed by quantification of total phenolics and total flavonoids. The ethanolic extract and the ethyl acetate fractions (SAF) and diclorometânica (FD) showed a strong antioxidant capacity, being that the SAF fraction was the most active, with EC50 of 3.07±0.05 μg.mL-1.The results show that the studied species is rich in phenolic compounds and has a strong antioxidant capacity, showing great potential for application as a natural antioxidant.

Phytochemical study of Waltheria viscosissima and evaluation of its larvicidal activity against Aedes aegypti

The species Waltheria viscosissima A.St.–Hil, Malvaceae, which is known as ‘malva-branca’, is traditionally used in the Brazilian northeast for the treatment of coughs. This research looks towards reporting the isolation of phytoconstituents of W. viscosissima, as well as the quantification of its phenolics, total flavonoid content, and free radical scavenging potential, along with an evaluation of its larvicidal activity against Aedes aegypti larvae. Chromatographic techniques were used to isolate the compounds and a structural elucidation was performed by 1D and 2D NMR. The quantification of total phenolics and flavonoids and the DPPH˙ radical scavenging activity was determined through spectrophotometric methods. Consequently, the phytochemical investigation led to the identification of fourteen compounds from the aerial parts of the W. viscosissima: steroids, triterpenes, alkaloids, and eight flavonoids previously reported in the literature. The quantification of compounds showed that the aerial parts extract possessed high concentration of flavonoids, while the roots extract were rich in other phenolic compounds. At the DPPH˙ free radical scavenging assay, the roots extract presented EC50 = 77.32 ± 4.37 µg/ml and the aerial parts extracts showed EC50 = 118.10 ± 1.21 µg/ml. W. viscosissima roots extract showed the most potent larvicidal activity against Ae. aegypti (LC50 = 4.78 mg/ml), with the potential of being used in effective and economically viable preparations that can be catered for domestic use towards controlling the vector insect of severe diseases, such as dengue and Zika.

LANNEA BARTERI ENGL. (ANACARDIACEAE) PLANT USED IN THE TREATMENT OF URINARY TRACT INFECTIONS IN IVORY COAST: BIOLOGICAL AND CHEMICAL STUDIES OF THE AQUEOUS EXTRACT

Objective: This research aims to evaluate the antibacterial activity and determine the chemical composition of the aqueous extract of the bark of Lannea barteri Engl. (DA) used in the traditional treatment of urinary tract infections in the Ivory Coast.Methods: The material is composed of DA, the bacterial strains of Pseudomonas aeruginosa and Acinetobacter baumannii, isolated from the urine of patients from different hospitals and subsequently stored. The qualitative analysis was performed using color-based detection tests and thin layer chromatography (TLC) reactions and the quantification of total phenols, flavonoids, flavone aglycones and anthocyanins using the method of Folin Ciocalteu. The method of diffusion on Mueller Hinton (MH) agar medium has been used for sensitivity tests. Results: The phytochemical screening of DA has revealed the presence of polyphenols, terpenes, and derivatives, coumarins, tannins, flavonoids, and alkaloids. Furthermore, the quantification of some polyphenols such as flavonoids, flavone aglycones, and anthocyanins was determined. The total polyphenols found was 0.757±0.003 mg/g MS representing respectively; 0.230±0.01 for flavonoids; 0.028±0.02 for flavone aglycones and 0.016±0.02 mg/g MS for anthocyanins. DA is bactericidal against Pseudomonas aeruginosa and Acinetobacter baumannii, which are mainly responsible for urinary tract infections.Conclusion: The bark of Lannea barteri Engl. (DA) is rich in flavonoids, flavone aglycones, and anthocyanins which are probably responsible for its antibacterial properties on Pseudomonas aeruginosa and Acinetobacter baumannii. This research thereby supports the use of this plant in the treatment of urinary tract infections.

ANALYSIS AND REVIEW OF PRESCRIBING CLINICAL DECISION SUPPORT SYSTEM WITHIN THE CONTEXT OF NHS SECONDARY SECTOR

The overall objective of this study was to evaluate in vitro the hemostatic activity of secondary metabolites (polyphones, flavonoïds and tannins) of Marrubium vulgare leaves, aromatic plant widely used in traditional medicine for the treatment of asthma, cough, diabetes ( by its effect on the pancreas to secrete insulin), heart disease, fever has a high efficiency as against inflammation. Qualitative analysis of the aqueous extract (AQE ) by thin layer chromatography revealed the presence of quercetin, kaempferol and rutin. Quantification of total phenols by Folin Ciocalteu method and flavonoïds by AlCl3 method gave high values with AQE: 175 ± 0.80 mg GAE per 100g of the dry matter, 23.86 ± 0.36 mg QE per 100g of dry matter. Moreover, the assay of condensed tannins by the vanillin method showed that AQE contains the highest value: 16.55 ± 0.03 mg E-Catechin per 100g of dry matter. Assessment of hemostatic activity by the plasma recalcification method (time of Howell) has allowed us to discover the surprising dose dependent anticoagulant effect of AQE lyophilized from leaves of M. vulgare. A positive linear correlation between the two parameters studied: the content of condensed tannins and hemostatic activity (r = 0.96 ) were used to highlight a possible role of these compounds that are potent vasoconstrictor activity in hemostatic. From these results we can see that Marrubium vulgre could be used for the treatment of health.

Anti-ulcerogenic and proton pump (H+, K+ ATPase) inhibitory activity of Clematis flammula L. extract

Clematis flammula L. (CF) (Ranunculaceae) is widely used traditionally by native Berber populations in Algeria to treat gastrointestinal disorders. The present study was conducted to assess the gastroprotective properties and the underlying mechanisms of CF leaves ethanolic extract (CFEE) in four ulcer models in mice. After total phenol quantification, the gastro-protective effect of the CFEE was evaluated by macroscopic and microscopic analyses, investigation of antioxidant (superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and pro-oxidant (malondialdehyde (MDA)) parameters. Furthermore, the impact of CFEE pre-treatment on mucus level, myeloperoxidase (MPO) and gastric proton pump (H+/K+-ATPase) activities was determined. Pro-kinetic properties were also assessed.Pharmacological investigation of CFEE showed a dose-dependent gastro-protective potential in different ulceration models, in close correlation with its high antioxidant activity (SOD, CAT and GSH). The most interesting underlying mechanisms were a remarkable reduction of MPO and proton pump activities (90 and 99% inhibition, respectively). Histological examination confirmed the preventive action of CFEE against offensive agents associated with increased mucus production and reduced gastric emptying and intestinal motility.Our findings provide a scientific basis for the ethno-pharmacological purpose of the studied plant.

Novel drug delivery systems for natural extracts: The case study of Vitis Vinifera extract-SiO2 nanocomposites

Ball Milling technique has been used to prepare for the first time Vitis Vinifera extract-silica nanocomposites (VV-SiO2 NCs), which combine the pharmacological effects of the extract with the effectiveness of silica as drug delivery system and active component in the treatment of wound healing. Different contents (1.0, 9.0 and 33.0 wt%) of Vitis Vinifera ethanolic extract were loaded into the silica matrix by grinding the extract with fumed silica using a planetary mill apparatus. The effect of the starting mixture composition and milling time on the final products was examined. The efficiency of the milling process was studied by X-ray Powder Diffraction, Nuclear Magnetic Resonance, and Infrared Spectroscopy, indicating that the natural extract was not affected by the increasing of the milling time. The successful loading of the extract was demonstrated by Nitrogen adsorption/desorption measurements, which showed a decrease in the SSA and pore volume of the silica with the increasing of the extract amount. Morphology of the nanocomposites, investigated by Scanning Electron Microscopy, showed an increased agglomeration in the nanocomposites with the increment of the VV extract amount. Studies on the total phenol quantification and antioxidant activity of the natural extract before and after incorporation in the silica matrix were also carried out. The obtained results indicate that the milling process does not alter the VV extract components, which result to be embedded in the silica matrix. An increase of the antioxidant activity with the increment of the extract amount in the nanocomposites, up to values comparable to the pure VV extract, was also observed.

Phytochemical Screening, Quantification of Total Phenols, Total Flavonoids and Antimicrobial Activity of Stem Extracts of Salacia Oblonga.

Phytochemical Screening, Quantification of Total Phenols, Total Flavonoids and Antimicrobial Activity of Stem Extracts of Salacia Oblonga.

Antioxidant activity shown by olive pomace extracts

ABSTRACTIn this study, the effects of experimental variables such as type of solvent, sample/solvent ratio, and time of extraction have been evaluated to individuate the best results in phenolic recovery by Olive Pomaces (OP) belonging to Carolea and Ottobratica cultivars. Folin–Ciocaulteu procedure and DPPH and ABTS assays were used, respectively, for total phenol quantification and total antioxidant activity of pomace extracts. The ethanol/water mixture was resulted the most efficient extraction solvent for both olive cultivars. The highest amount of phenolic compounds (171 ± 4 mg of gallic acid 100 g−1 of dry pomace) was obtained after extraction at 120 min with 2:1 solvent/OP (v/w) of Ottobratica Olive Pomace. The recovery of phenol compounds from olive wastes increases the sustainability of sector, allowing obtaining an extract that could be a suitable alternative in the food industry to the use of synthetic antioxidants in order to improve the quality of foods.

Determination of Antioxidant Capacity, Flavonoids and Total Phenolic Content of Extracts from Atractylis flava Desf

objective: The aim of the present study was to evaluate the ability of different extracts (PE, DCM, EtAOc and n-BuOH) obtained from Atractylis flava Desf to prevent oxidation using several methods in vitro. Materials and Methods: The capacity of samples for scavenging free radicals (ABTS+, DPPH), preventing lipid peroxidation (s-carotene), chelating metal ions, CUPRAC, reducing power. The quantification of total phenols was performed using Folin-Ciocalteu reagent and the total flavonoid content was performed by the trichloroaluminum method. Results: The highest concentrations of total polyphenols and flavonoids were found in the n-BuOH extract (122,74 ± 0,78 µg GAE/ml and 66,75±6,12 µg QE/ml, respectively). EtAOc and n-BuOH extracts were the most active for scavenging DPPH (IC50 = 158,41±3,24 and IC50 = 427,53±4,69 µg/mL, respectively), and EtAOc extract was also the best for scavenging ABTS+ radicals (IC50 = 15,57±2,93 µg/mL). EtAOc extract possessed the best capacity for preventing lipid peroxidation (IC50 = 16,52±1,87 µg/mL) and CUPRAC assay (A0.50 = 28,58±0,65 µg/mL). The results of ferric reducing power ability of all the tested samples were affected in a dose-dependent manner. Conclusions: These results suggest that Atractylis flava Desf have strong antioxidant potential. Further study is necessary for isolation and characterization of t of the active antioxidant agents, which can be used to treat various oxidative stress-related diseases.

Pharmacognostical, Phytochemical and Antioxidant Evaluations of Guettarda calyptrata A. Rich.

Guettarda calyptrata A. Rich., originally from Cuba and known as “Contraguao”, has traditionally been used to counteract quickly and effectively burns produced by Comocladia dentate Jacq (Guao), vegetable species that secretes a highly caustic latex for skin and mucous membranes. A burn is a traumatic injury resulting in local and systemic injury with oxidative changes; in this sense the antioxidants play an important role. In order to offer aspects related to the quality and effectiveness of the plant, its pharmacognostic, phytochemical and antioxidant activity is presented. The morphoanatomical evaluation was carried out, physical-chemical parameters were determined for the crude drug and for the aqueous extract. The chemical profile of the extract was estimated by thin layer chromatography, ultraviolet-visible and quantification of total phenols by Folin-Ciocalteu and total flavonoids by the colorimetric method of aluminum trichloride (AlCl3). Finally, the antioxidant activity was tested by the FRAP and DPPH techniques. Through the pharmacognostic study, the quality specifications of the drug and the extract were established. The methods of analysis used for the chemical profile suggested the presence of flavonoids and phenols in general. The aqueous extract showed antioxidant properties by the two methods evaluated. The study of G. calyptrata provided pharmacognostic, phytochemical and effectiveness as an antioxidant evidence, aspects to consider in the possible use of the plant by our Natural and Traditional Medicine.

Measurement of ripening of raspberries (Rubus idaeus L) by near infrared and colorimetric imaging techniques.

This work includes the evaluation of 168 samples of raspberries 'Glen Lyon', representing whole maturation period, by colorimetric and near infrared imaging techniques, as well as the quantification of total phenols, total anthocyanins and antioxidant activity by chemical methods. Samples showed significant differences depending on the maturation stage using CIELAB colour parameters and total anthocyanins content. The application of partial least squares regression allowed predicting the chemical features from image analysis data, with coefficients of determination (R2) up to 0.75. The best prediction for total anthocyanins including colorimetric data was observed. The proposed methodology can be used as a reference method for assessing important quality attributes of raspberries. Moreover, it is useful, rapid and accurate automatic inspection method.

Quantification of total phenols, flavonoides and tannins from Ziziphus jujuba (mill.) and Ziziphus lotus (l.) (Desf). Leaf extracts and their effects on antioxidant and antibacterial activities

This work was performed to determine the biochemical composition, antioxidant and antimicrobial activities of leaf extracts collected from four different provenances: Mahdia and Mahres ( Ziziphus jujuba ); Kairouan and Rouhia ( Ziziphus lotus ). Total phenols, flavonoids, tannins contents and antioxidant activity were evaluated using the Folin ciocalteux, Aluminum trichloride, vanillin and scavenging activity on 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radicals methods, respectively. The antimicrobial activity was evaluated against three bacterial strains ( Escherichia coli , Staphylococcus aureus and klebsiella pneumoniea ) and three fungal strains ( Fusarium culmorum , Fusarium solani and Botrytis cinerea ) , according to well Agar diffusion method. Total phenols and flavonoids were present at levels of 21.98 mg GAE /g DW and 7.80 mg ER/g DW ; respectively in Ziziphus lotus . These levels did not exceeded 13.70 mg GAE /g DW and 6.73 mg ER/g DW for Ziziphus jujuba . The tannin contents were present in equal levels (7.9 mg EC/g DW) in two species . The high antioxidant activity (0.01 µg/ml) was noted in Rouhia provenance. The Ziziphus lotus leaf extracts showed promising efficiency against all tested microorganisms with a zone of inhibition ranging between 22 and 23.5 mm. This study could validate the medicinal potential of Ziziphus specie and explain why tunisian people traditionally use it in medicine to treat several pathologies. Ziziphus leaf extracts may be suggested in foods and pharmaceutical industries. Leaf extracts proved also to be effective against tested microorganisms. So, a n adequate toxicological study must be carried out to verify the possibility of using these plants for fighting microorganisms.

Quantificação de fenóis, flavonoides totais e atividades farmacológicas de geoprópolis de Plebeia aff. Flavocincta do Rio Grande do Norte

Resumo: Esse estudo objetivou avaliar a composição química e potencial terapêutico do extrato hidroalcóolico de geoprópolis produzidas por abelhas Plebeia aff. flavocincta no semiárido do Rio Grande do Norte. Oito amostras (A-H) foram submetidas a quantificação dos teores de fenóis e flavonoides totais e avaliação da atividade antioxidante através do método DPPH (2,2-difenil-1-picril-hidrazilo). Além disso, foram investigadas as atividades antibacteriana, através do método de difusão em ágar, e a cicatrizante, através da indução de feridas cirúrgicas experimentais em Rattus norvegicus Berkenhout, 1769, linhagem Wistar, tratados com creme à base de geoprópolis. Duas amostras (F e G) se destacaram por apresentar altos valores de fenóis e flavonoides totais. A capacidade antioxidante acima de 90% foi observada em cinco amostras. Os extratos foram considerados eficazes no que se refere a atividade antibacteriana, pois das oito amostras, cinco promoveram a formação de halos de inibição ≥9mm para todas as cepas testadas. Duas amostras (D e G) se destacaram em relação as demais por apresentar excelentes resultados, uma vez que, promoveram a formação de halos de inibição para as bactérias Staphylococcus epidermidis e Escherichia coli, superiores estatisticamente aos valores dos antibióticos controles, quando na concentração de 100%. As amostras A e G promoveram, respectivamente, a formação de halos de inibição, que não diferiram significativamente dos halos produzidos pelos antibióticos controles em todas as concentrações testadas para E. coli e Staphylococcus aureus. A análise do processo de cicatrização sob os pontos de vista clínico, macroscópico e histológico permitiu concluir, que o uso do creme à base de geoprópolis apresentou influência positiva na cicatrização de feridas cutâneas experimentais, por promover reação inflamatória menos intensa e fechamento mais rápido das feridas em relação ao grupo controle.

LIFE: International Journal of Health and Life-Sciences

The overall objective of this study was to evaluate in vitro the hemostatic activity of secondary metabolites (polyphones, flavonoids and tannins) of Marrubium vulgare leaves, aromatic plant widely used in traditional medicine for the treatment of asthma, cough, diabetes ( by its effect on the pancreas to secrete insulin), heart disease, fever has a high efficiency as against inflammation. Qualitative analysis of the aqueous extract (AQE ) by thin layer chromatography revealed the presence of quercetin, kaempferol and rutin. Quantification of total phenols by Folin Ciocalteu method and flavonoids by AlCl3 method gave high values with AQE: 175 ± 0.80 mg GAE per 100g of the dry matter, 23.86 ± 0.36 mg QE per 100g of dry matter. Moreover, the assay of condensed tannins by the vanillin method showed that AQE contains the highest value: 16.55 ± 0.03 mg E-Catechin per 100g of dry matter. Assessment of hemostatic activity by the plasma recalcification method (time of Howell) has allowed us to discover the surprising dose dependent anticoagulant effect of AQE lyophilized from leaves of M. vulgare. A positive linear correlation between the two parameters studied: the content of condensed tannins and hemostatic activity (r = 0.96 ) were used to highlight a possible role of these compounds that are potent vasoconstrictor activity in hemostatic. From these results we can see that Marrubium vulgre could be used for the treatment of health. Article DOI: https://dx.doi.org/10.20319/lijhls.2016.s21.253258 This work is licensed under the Creative Commons Attribution-Non-commercial 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.

Cytotoxic, antioxidant and phytochemical analysis of Gracilaria species from Persian Gulf.

Background:Marine algae, also called seaweeds, are abundantly present in the coastal area of Iran, especially in Persian Gulf. These plants contain important phytochemical constituents and have potential biological activities. The present study investigated the presence of phytochemical constituents and total phenolic quantification of the seaweeds Gracilaria salicornia and Gracilaria corticata. Cytotoxicity of seaweeds was tested against HT-29, HeLa, and MCF-7 cell lines. Antioxidant potential of these two Gracilaria species was also analyzed.Materials and Methods:Extracts of G. salicornia and G. corticata were subjected to phytochemical and cytotoxicity tests. Phytochemical screenings were employed to identify the chemical constituents and total phenolic content. Cytotoxicity was characterized by IC50 of human cancer cell lines (MCF-7, HeLa, and HT-29) using sulforhodamine assay. Antioxidant activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl.Results:The analysis revealed that tannins were the most abundant compounds in G. corticata while sterols and triterpenes were the most abundant ones in G. salicornia, but the total phenolic content of the two seaweeds was similar. Cytotoxic results showed that both species could inhibit cell growth effectively, especially against HT-29 cell line.Conclusion:Considerable phytochemicals, high antioxidant potential, and moderate cytotoxic activity of G. salicornia and G. corticata make them appropriate candidates for further studies and identification of their bioactive principles.

Diffuse reflectance Fourier transform infrared spectroscopy for simultaneous quantification of total phenolics and condensed tannins contained in grape seeds

Total phenolic and condensed tannin contents of grape seeds were simultaneously quantified using diffuse reflectance Fourier transform spectroscopy and partial least squares (PLS). The results were compared with those obtained using the conventional methods. Infrared spectra were recorder in solid state samples after freeze drying. The second derivative of the 1560–1177cm−1 spectral region was used for total phenolic determination. The determination coefficient (R2) was 0.97, the root-mean-square error of calibration (RMSEC) 4.03, and the root-mean-square error of prediction (RMSEP) 6.49. For the condensed tannin content, the 2nd derivative of the spectral regions 1670–950 (R2=0.99; RMSEC=7.01; RMSEP=10.13) and 3750–2125cm−1 (R2=0.99; RMSEC=2.65; RMSEP=3.97) was correlated with the concentration estimated by means of methylcellulose and bovine serum albumin assays, respectively. The proposed method in comparison with the conventional methods is simpler, less time consuming, more economical, and requires reduced quantities of chemical reagents and less sample processing prior to analysis. This might by a valuable tool for wine industry where the quantification of grape tannins in a large number of samples remains a priority.

English

The objective of this study was to evaluate the phytotoxicity of Solanum aculeatissimum Jacq. leaves ethanolic extract in seeds germination, development and fixation of Lactuca sativa seedlings. The same study also aimed to assess the mitotic index of lettuce roots meristematic cells, quantification of phenols and total flavonoids and triage by mean of phytochemical testing of the main secondary metabolites classes. Bioassays of germination, development of root and hypocotyl were carried out in Petri dishes using achenes of Lactuca sativa L. cv. 'Grand Rapids' (lettuce). Concomitantly, were evaluated the physico-chemical characteristics (pH, osmotic potential and electrical conductivity), mitotic index, quantification of total phenols and flavonoids and determination of phytochemical profile of the treatments extract. The results obtained in the bioassays demonstrate that the ethanol extract of S. aculeatissimuma presents phytotoxic potential in the development of lettuce seedlings, given that the concentration of 20 mg/ml showed greater inhibition (41% of germination). The extract contains significant amounts of antioxidants, total flavonoid and phenols, where the concentration 1000µg/mL showed higher values (86.50%). Furthermore, it was possible to observe the presence of compounds with allelopathic activity in the phytochemical screening test as coumarins, tannins, terpenes, flavonoids and alkaloids. Given the above it is clear that the ethanolic extract of S. aculeatissimum presents allelopathic substances with phytotoxic activity that can affect the germination and development of other plant species in their natural environment. Key words: Allelopathy, antioxidants, 1,1-diphenyl-2-picrylhydrazyl (DPPH) test, Lactuca sativa.