Quinoa is a good source of phenolics,which both exist as free and bound forms.In order to mark clear the characteristic free and bound phenolics in different quinoa samples,in this study,characteristic free and bound ...Quinoa is a good source of phenolics,which both exist as free and bound forms.In order to mark clear the characteristic free and bound phenolics in different quinoa samples,in this study,characteristic free and bound phenolics in three colored quinoas including WQ(white quinoa),RQ(red quinoa)and BQ(black quinoa)were investigated.Result showed a total of 14 phenolics both acted as free and bound form were analyzed in three colored quinoas(WQ,RQ and BQ).Gallic acid,vanillic acid,epicatechin,p-coumaric acid and quercetin existed both as free and bound forms were common phenolics in quinoas.The highest total free phenolics(238.10 mg/kg)and bound phenolics(3377.75 mg/kg)were presented in WQ and RQ,respectively.It indicated WQ and RQ were respectively good source of free and bound phenolics.Moreover,characteristic free and bound phenolics in three colored quinoas could be well analyzed by principal component analysis(PCA),indicating it was an effective and reliable method in distinguishing three colored quinoas based on their characteristic free and bound phenolics,respectively.展开更多
A variety of alcohols and phenols are efficiently acetylated with acetic anhydride in the presence of a catalytic amount of V（HSO4）3 in solution and under solvent free conditions. Mild reaction conditions, high yiel...A variety of alcohols and phenols are efficiently acetylated with acetic anhydride in the presence of a catalytic amount of V（HSO4）3 in solution and under solvent free conditions. Mild reaction conditions, high yields of the products, easy procedure and selective acetylation of alcohols and phenols in the presence of amines and thiols are the main advantages of this procedure.展开更多
A simple and efficient solvent-free method was developed for the acetylation of alcohols, phenols and amines in excellent yields employing glycerol-based sulfonic acid (-SO3H) functionalized carbon catalyst under envi...A simple and efficient solvent-free method was developed for the acetylation of alcohols, phenols and amines in excellent yields employing glycerol-based sulfonic acid (-SO3H) functionalized carbon catalyst under environmentally benign reaction conditions. The salient features of this protocol are the short reaction time, ease of product isolation and reusability of the carbon catalyst.展开更多
Objective:To determine the antioxidant activity,total phenolic and flavonoid content of Petroleum ether extract（PE）,Dichloromethane extract（DCM）,Ethanol extract（ET） and aqueous extract（AQ） of henna seeds.Metho...Objective:To determine the antioxidant activity,total phenolic and flavonoid content of Petroleum ether extract（PE）,Dichloromethane extract（DCM）,Ethanol extract（ET） and aqueous extract（AQ） of henna seeds.Methods:Total antioxidant assay（phosphomolybenum method）, DPPH radical scavenging assay,reducing power assay and lipid peroxidation inhibition assay were used to ascertain the potential of seeds as an antioxidant.Results:In all the assays carried out ET showed a greater potential to scavenge DPPH radical,reduce MO（Ⅳ） to MO（Ⅴ） complex and Fe（Ⅲ） to Fe（Ⅱ） and to inhibit lipid peroxidation.The IC<sub>50</sub> of ET was far greater than that of the standard,ascorbic acid（AS） in the lipid peroxidation assay.The activity of AQ was lesser when compared with that of ET but greater than PE and DCM.The amount of phenolics and flavonoids were present in higher amounts in ET followed by AQ.Trace amounts of phenolics were detected in PE and DCM,but the amount of flavonoids were below the detection level.The study showed that the antioxidant activity and the concentrations of phenolics and flavonoids are proportionate to each other.Conclusions:Ethanolic extract of henna seeds are efficient antioxidants,which can be utilized for further isolation of active compounds and pharmaceutical applications.展开更多
Silica triflate, as a new silica-based reagent, can be used for the efficient synthesis of 4-substituted coumarins via a Pechmann reaction under solvent-free reaction conditions. All reactions were performed at 80 ℃ ...Silica triflate, as a new silica-based reagent, can be used for the efficient synthesis of 4-substituted coumarins via a Pechmann reaction under solvent-free reaction conditions. All reactions were performed at 80 ℃ in good to high yields.展开更多
Objective: To evaluate the phytochemical present in various solvent extracts from leaves of Ocimum sanctum(L.), Swertia chirayita(L.), Butea monosperma(Lam.) and Stevia rebaudiana(Bert.) as well as antioxidant and ant...Objective: To evaluate the phytochemical present in various solvent extracts from leaves of Ocimum sanctum(L.), Swertia chirayita(L.), Butea monosperma(Lam.) and Stevia rebaudiana(Bert.) as well as antioxidant and anticholinergic activities employing different in vitro models. Methods: Total phenol content of diethyl ether, chloroform and methanolic extracts obtained from leaves of different medicinal plants was determined by Folin-Ciocalteau's spectrophotometric method. Moreover, antioxidant and anticholinergic studies were conducted by four different in vitro methods which included diphenyl picrylhydrazyl radical scavenging, 2,2-azinobis(3-ethylbezoline-6-sulphonic acid), reducing activity by ferrous reduced antioxidant power and anti-acetylcholinesterase assay, in order to ensure pharmacological potential of the plants. Results: The methanolic leaf extract of Ocimum sanctum showed the highest total phenol content which was(21.13±1.04) GAE/g DW and antioxidant activities compared to other plants with the IC50 value of 40.43 μg/mL in diphenyl picrylhydrazyl radical scavenging assay and 53.5 μg/mL in 2,2-azinobis(3-ethylbezoline-6-sulphonic acid) assay as well as metal ion reduced by(78.22±0.38) TE/g DW in ferrous reduced antioxidant power assay. The inhibition percentage of the anti-acetylcholinesterase assay was(94.22±0.26)%. Conclusions: The results of our current study show that Ocimum sanctum leaf is the most significant source of phytochemicals that possesses antioxidant and anticholinergic properties. However, further investigation on isolation and characterization of active compound which is responsible for the pharmacological potential is needed.展开更多
Oxalic acid was found to be an efficient catalyst for Pechmann condensation, which includes the reaction between phenols and β-keto esters leading to formation of coumarin derivatives. The advantages of present metho...Oxalic acid was found to be an efficient catalyst for Pechmann condensation, which includes the reaction between phenols and β-keto esters leading to formation of coumarin derivatives. The advantages of present methods are the use of cheap and easy available catalyst, solvent-free reaction conditions, better yields and shorter reaction time.展开更多
Due to their beneficial effects on human health, phenolic compounds are increasingly attracting the attention of scientists and researchers all over the world. The main interest is in the extraction process of those n...Due to their beneficial effects on human health, phenolic compounds are increasingly attracting the attention of scientists and researchers all over the world. The main interest is in the extraction process of those natural plant-originated compounds from fruits, vegetables and plant wastes, namely grape wastes, in which phenolic compounds are the most abundant secondary metabolites. This waste exploitation not only re-assimilates those byproducts into the food cycle, but also avoids major environmental problems. Herein, the optimization of the phenolic compounds concentration and free radical scavenging activity from Cabernet Sauvignon grape byproducts was conducted, using multi-response surface methodology. A conventional solid-liquid extraction process was performed with pure water as a solvent to study the effects of both time and temperature on the procedure. The maximal phenolic compounds concentration (878.9 mg/L) was reached at 47℃ after 30 hours while the optimal free radical scavenging activity (41.15%) was obtained at 30℃ after 20 hours. A multi-response surface methodology compromised between the quantity and the quality of the extracted phenolics, and the parameters maximizing both responses were obtained at 37℃ and 28 hours. This low-cost and energy saving process provides an excellent tool for further industrial applications.展开更多
基金support of Youth Project of Liaoning Provincial Education Department(JYTQN2023334)Anhui Provincial Department of Education Key Research Project on Natural Science in Higher Education Institutions(KJ2021A1072)Science and Technology Plan Project of Chuzhou Science and Technology Bureau(2021ZD023).
文摘Quinoa is a good source of phenolics,which both exist as free and bound forms.In order to mark clear the characteristic free and bound phenolics in different quinoa samples,in this study,characteristic free and bound phenolics in three colored quinoas including WQ(white quinoa),RQ(red quinoa)and BQ(black quinoa)were investigated.Result showed a total of 14 phenolics both acted as free and bound form were analyzed in three colored quinoas(WQ,RQ and BQ).Gallic acid,vanillic acid,epicatechin,p-coumaric acid and quercetin existed both as free and bound forms were common phenolics in quinoas.The highest total free phenolics(238.10 mg/kg)and bound phenolics(3377.75 mg/kg)were presented in WQ and RQ,respectively.It indicated WQ and RQ were respectively good source of free and bound phenolics.Moreover,characteristic free and bound phenolics in three colored quinoas could be well analyzed by principal component analysis(PCA),indicating it was an effective and reliable method in distinguishing three colored quinoas based on their characteristic free and bound phenolics,respectively.
基金this work by the research affair,University of Guilan,Rasht,Iran,
文摘A variety of alcohols and phenols are efficiently acetylated with acetic anhydride in the presence of a catalytic amount of V（HSO4）3 in solution and under solvent free conditions. Mild reaction conditions, high yields of the products, easy procedure and selective acetylation of alcohols and phenols in the presence of amines and thiols are the main advantages of this procedure.
文摘A simple and efficient solvent-free method was developed for the acetylation of alcohols, phenols and amines in excellent yields employing glycerol-based sulfonic acid (-SO3H) functionalized carbon catalyst under environmentally benign reaction conditions. The salient features of this protocol are the short reaction time, ease of product isolation and reusability of the carbon catalyst.
文摘Objective:To determine the antioxidant activity,total phenolic and flavonoid content of Petroleum ether extract（PE）,Dichloromethane extract（DCM）,Ethanol extract（ET） and aqueous extract（AQ） of henna seeds.Methods:Total antioxidant assay（phosphomolybenum method）, DPPH radical scavenging assay,reducing power assay and lipid peroxidation inhibition assay were used to ascertain the potential of seeds as an antioxidant.Results:In all the assays carried out ET showed a greater potential to scavenge DPPH radical,reduce MO（Ⅳ） to MO（Ⅴ） complex and Fe（Ⅲ） to Fe（Ⅱ） and to inhibit lipid peroxidation.The IC<sub>50</sub> of ET was far greater than that of the standard,ascorbic acid（AS） in the lipid peroxidation assay.The activity of AQ was lesser when compared with that of ET but greater than PE and DCM.The amount of phenolics and flavonoids were present in higher amounts in ET followed by AQ.Trace amounts of phenolics were detected in PE and DCM,but the amount of flavonoids were below the detection level.The study showed that the antioxidant activity and the concentrations of phenolics and flavonoids are proportionate to each other.Conclusions:Ethanolic extract of henna seeds are efficient antioxidants,which can be utilized for further isolation of active compounds and pharmaceutical applications.
文摘Silica triflate, as a new silica-based reagent, can be used for the efficient synthesis of 4-substituted coumarins via a Pechmann reaction under solvent-free reaction conditions. All reactions were performed at 80 ℃ in good to high yields.
基金supported by Centre of Excellence(COE)TEQ IP-Ⅱ for Grant no.-NPIU/TEQUIP II/FLN/31/158,Birla institute of Technology,Mesra,Ranchi,Jharkhand
文摘Objective: To evaluate the phytochemical present in various solvent extracts from leaves of Ocimum sanctum(L.), Swertia chirayita(L.), Butea monosperma(Lam.) and Stevia rebaudiana(Bert.) as well as antioxidant and anticholinergic activities employing different in vitro models. Methods: Total phenol content of diethyl ether, chloroform and methanolic extracts obtained from leaves of different medicinal plants was determined by Folin-Ciocalteau's spectrophotometric method. Moreover, antioxidant and anticholinergic studies were conducted by four different in vitro methods which included diphenyl picrylhydrazyl radical scavenging, 2,2-azinobis(3-ethylbezoline-6-sulphonic acid), reducing activity by ferrous reduced antioxidant power and anti-acetylcholinesterase assay, in order to ensure pharmacological potential of the plants. Results: The methanolic leaf extract of Ocimum sanctum showed the highest total phenol content which was(21.13±1.04) GAE/g DW and antioxidant activities compared to other plants with the IC50 value of 40.43 μg/mL in diphenyl picrylhydrazyl radical scavenging assay and 53.5 μg/mL in 2,2-azinobis(3-ethylbezoline-6-sulphonic acid) assay as well as metal ion reduced by(78.22±0.38) TE/g DW in ferrous reduced antioxidant power assay. The inhibition percentage of the anti-acetylcholinesterase assay was(94.22±0.26)%. Conclusions: The results of our current study show that Ocimum sanctum leaf is the most significant source of phytochemicals that possesses antioxidant and anticholinergic properties. However, further investigation on isolation and characterization of active compound which is responsible for the pharmacological potential is needed.
文摘Oxalic acid was found to be an efficient catalyst for Pechmann condensation, which includes the reaction between phenols and β-keto esters leading to formation of coumarin derivatives. The advantages of present methods are the use of cheap and easy available catalyst, solvent-free reaction conditions, better yields and shorter reaction time.
文摘Due to their beneficial effects on human health, phenolic compounds are increasingly attracting the attention of scientists and researchers all over the world. The main interest is in the extraction process of those natural plant-originated compounds from fruits, vegetables and plant wastes, namely grape wastes, in which phenolic compounds are the most abundant secondary metabolites. This waste exploitation not only re-assimilates those byproducts into the food cycle, but also avoids major environmental problems. Herein, the optimization of the phenolic compounds concentration and free radical scavenging activity from Cabernet Sauvignon grape byproducts was conducted, using multi-response surface methodology. A conventional solid-liquid extraction process was performed with pure water as a solvent to study the effects of both time and temperature on the procedure. The maximal phenolic compounds concentration (878.9 mg/L) was reached at 47℃ after 30 hours while the optimal free radical scavenging activity (41.15%) was obtained at 30℃ after 20 hours. A multi-response surface methodology compromised between the quantity and the quality of the extracted phenolics, and the parameters maximizing both responses were obtained at 37℃ and 28 hours. This low-cost and energy saving process provides an excellent tool for further industrial applications.
