Quantification of Total Phenols, Total Flavonoids, Total Anthocyanins and Evaluation of Antioxidant and Antiradical Activities of Detarium Senegalense Extracts from Chad

The aim of the present work is to assess the value of Detarium Senegalense by determining the content of total phenols, total flavonoids and total anthocyanins, and by evaluating the free radical scavenging activity of Detarium Senegalense extracts. For this purpose, sequential extraction using solvents of increasing polarity was essential. The various extracts obtained underwent phytochemical and biochemical analyses. Phytochemical screening revealed the presence of flavonoids, alkaloids, tannins, polyphenols, anthocyanins and steroids/terpenes. Quantitative analysis of total polyphenols, total flavonoids and total anthocyanins yielded the following results: total flavonoids (0.803 ± 0029 mg EQ/100g P for acetone extract of roots and 0.871 ± 0.401 mg EQ/100g P for methanol extract of leaves);total polyphenols (23.298 ± 12.68 mg EAG/100g P for acetone extract of roots and 24.69 ± 0.49 401 mg EAG/100g P for methanol extract of leaves);total monomeric anthocyanins (44.697 ± 0.939 mg EC3G/100g P and 16.699 ± 0.193 mg EC3G/100g P respectively for acetone and methanol extracts of stem bark). DPPH free radical scavenging activity was 1.674 ± 0.023 mg/mL for the acetone extract and 0.934 ± 0.24 mg/mL for the methanol extract of roots. .

Composition and antioxidant activity of Paeonia lactiflora petal flavonoid extract and underlying mechanisms of the protective effect on H_(2)O_(2)-induced oxidative damage in BRL3A cells

Flavonoids have attracted considerable attention due to their health benefits. This study aimed to investigate the flavonoid profiles and antioxidant activity of Paeonia lactiflora petal flavonoid extract(PPF). The UHPLC-ESI-Q-Exactive HF MS/MS method was established for characterization, and 21 predominant flavonoid compounds were tentatively identified in PPF. Among them, isoscutellarein-7-(6’-acetylallosyl-(1->2)-glucoside) and scutellarin methylester were discovered in PPF for the first time. Pretreatment with PPF significantly reduced H2O2-induced cell damage, ROS accumulation, and malondialdehyde content and increased the activity of SOD, CAT, and GSH-Px in buffalo rat liver 3A(BRL3A) cells. Moreover, the expression of nuclear Factor E2-related factor(Nrf2) was upregulated by PPF, whose expression trend was consistent with that of heme oxygenase-1(HO-1), glutamate-cysteine ligase catalytic subunit(GCLC), and NAD(P)H quinone oxidoreductase-1(NQO1). These findings suggested that herbaceous peony flavonoids can be used as a natural bioactive agent to prevent oxidative stress.

Extraction,Antioxidant Activity and Identification of Flavonoids from Root Tubers of Kosteletzkya virginica

Kosteletzkya virginica(K.virginica)is used for revegetation of salt-affected coastal tidal flats and as a raw material of biodiesel.K.virginica root tuber,a biowaste with low economic value,is rich in bioactive compounds.This study aimed to extract and identify flavonoids from K.virginica root tubers.The optimal extraction conditions were 1/25(w/v)solid/liquid ratio,40%ethanol concentration at 40℃ for 60 min.Under these conditions,65.2±3.7 mg/g total flavonoid content was extracted from the roots,which were collected from salinized soil in late autumn of the third year.Antioxidant activity was evaluated through 1,1-diphenyl-2-picrylhydrazyl,hydroxyl radical,and superoxide anion scavenging assays.The extracted flavonoids exhibited antioxidant activity in a dose-dependent manner.Five flavonoids,glucoliquiritin apioside,licoisoflavone B,5-methoxy-7,8-diprenylflavone,7,2′-dihydroxy-6,8-dimethyl-4′,5′-methylenedioxyflavan,and 5,7,4′-trihydroxy-3′-methoxy-6,8-di-Cmethylflavanone,were identified by ultra-performance liquid chromatography–tandem mass spectrometry.Our results suggest that the flavonoids of K.virginica root tubers might be potent antioxidants and can be effectively applied as an ingredient in food and natural medicine.

Effects of Heat Treatment on Flavonoids Content and Antioxidant Capacity of Buckwheat (Fagopyrum tataricum Gaert) Flour Ethanolic Extracts

The chemical composition, total flavonoids and antioxidant capacity of 50% ethanolic extracts from raw and cooked buckwheat flour from southwest of China were determined. The heat treatment used to gelatinize the flour starch significantly reduced the total flavonoids in the extract from 83.52 to 67.36 mg 100 g 1 of dry matter in the raw and cooked flour, respectively. The antioxidant capacity of the extracts was evaluated using autooxidation in a β carotene linoleate model system (AA or AAC), DPPH radical scavenging assay (IP) and oxygen radical absorbance capacity (ORAC) assay. Values for raw buckwheat flour extract were 97.84, 874.31, 76.45 and 94.92% for AA, AAC, ORAC and IP, respectively, while values in cooked buckwheat flour were 86.14, 842.88, 63.93 and 94.74% for AA, AAC, ORAC and IP, respectively. Values before cooked and raw buckwheat flour extracts were significantly different ( P <0.05) for AA, AAC, and ORAC.

Multidisciplinary strategies to enhance therapeutic effects of flavonoids from Epimedii Folium:Integration of herbal medicine,enzyme engineering,and nanotechnology

Flavonoids such as baohuoside I and icaritin are the major active compounds in Epimedii Folium(EF)and possess excellent therapeutic effects on various diseases.Encouragingly,in 2022,icaritin soft capsules were approved to reach the market for the treatment of hepatocellular carcinoma(HCC)by National Medical Products Administration(NMPA)of China.Moreover,recent studies demonstrate that icaritin can serve as immune-modulating agent to exert anti-tumor effects.Nonetheless,both production efficiency and clinical applications of epimedium flavonoids have been restrained because of their low content,poor bioavailability,and unfavorable in vivo delivery efficiency.Recently,various strategies,including enzyme engineering and nanotechnology,have been developed to increase productivity and activity,improve delivery efficiency,and enhance therapeutic effects of epimedium flavonoids.In this review,the structure-activity relationship of epimedium flavonoids is described.Then,enzymatic engineering strategies for increasing the productivity of highly active baohuoside I and icaritin are discussed.The nanomedicines for overcoming in vivo delivery barriers and improving therapeutic effects of various diseases are summarized.Finally,the challenges and an outlook on clinical translation of epimedium flavonoids are proposed.

Distribution of antioxidants and phenolic compounds in flour milling fractions from hard red winter wheat

Mature wheat kernels contain three main parts:endosperm,bran,and germ.Flour milling results in multiple streams that are chemically different;however,the distribution of antioxidants and phenolic compounds has not been well documented in terms of conventional milling by-product streams.In this study,multiple analytical methods were used to investigate antioxidant activity and phenolic compound compositions of hard red winter wheat(whole ground wheat),the parts of a wheat kernel(bran,flour,germ),and wheat by-product streams(mill feed,red dog,shorts)for the first time.For each mill stream,phenolic compounds(total,flavonoid,and anthocyanin contents)were determined and antioxidant activities were evaluated with 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical-scavenging activity,ferric reducing/antioxidant power(FRAP),and total antioxidant capacity assays.Significant differences(P<0.05)were observed in phenolic concentrations among fractions of bran,flour,and germ milled from the same kernels and noted that germ accounts for the majority of antioxidant properties,whereas bran contains a substantial portion of phenolic compounds and anthocyanins.Mill feed was high in phenolic content(5.29 mg FAE/g),total antioxidant capacity(866 mg/g),and antioxidant activity(up to 75% DPPH inhibition and 20.26μmol FeSO_(4)/g).The comprehensive information on distribution of antioxidants and phenolic compounds provides insights for future human consumption of commonly produced co-products from flour milling,and for selecting and using different milling fractions to make foods with improved nutritional properties.

Antioxidant and Hypoglycemic Ability of Ardisia gigantifolia Stapf Parts

[Objectives]To study the antioxidant and hypoglycemic effects of different parts of Ardisia gigantifolia Stapf.[Methods]The hydroxyl radical scavenging activity,DPPH radical scavenging activity and total antioxidant capacity of ABTS of 75%ethanol extract of A.gigantifolia Stapf and the petroleum ether,ethyl acetate,n-butanol,chloroform and aqueous extract were measured with Vc as positive control.At the same time,acarbose was used as reference substance to determine the inhibitory effect of each polar site onα-glucosidase.[Results]All parts of A.gigantifolia Stapf had antioxidant activity,among which ethyl acetate had the strongest antioxidant activity,and the scavenging rate of hydroxyl radical and DPPH radical was higher than that of positive control.The results showed that petroleum ether,ethyl acetate and chloroform had a good inhibitory effect onα-glucosidase(better than acarbose).[Conclusions]The ethyl acetate part of A.gigantifolia Stapf had the best antioxidant activity and inhibitory effect onα-glucosidase.It provides a basis for further research and development of A.gigantifolia Stapf.

In vitro total phenolics,flavonoids contents and antioxidant activity of essential oil,various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah

Objective:To detect the in vitro total phenolics,flavonoids contents and antioxidant activity of essential oil,various organic extracts from the leaves of tropical medicinal plant Tetrastigma from Sabah.Methods:The dry powder leaves of Tetrastigma were extracted with different organic solvent such as hexane.ethyl acetate,chloroform,butanol and aqueous methanol.The total phenolic and total flavonoids contents of the essential oil and various organic extracts such as hexane,ethyl acetate,chloroform,butanol and aqueous ethanol were determined by Folin-Ciocalteu method and the assayed antioxidant activity was determined in vitro models such as antioxidant capacity by radical scavenging activity usingα,α-diphenyl-β-picrylhydrazyl (DPPH) method.Results:The total phenolic contents of the essential oil and different extracts as gallic acid equivalents were found to be highest in methanol extract(386.22 mg/g) followed by ethyl acetate(190.89 mg/g).chloroform(175.89 mg/g).hexane(173.44 mg/g).and Imtanol extract (131.72 mg/g) and the phenolic contents not detected in essential oil.The antioxidant capacity of the essential oil and different extracts as ascorbic acid standard was in the order of methanol extract】ethyl acetate extract】chloroform】butanol】hexane extract also the antioxidant activity was not detected in essential oil.Conclusions:The findings show that the extent of antioxidant activity of the essential oil and all extracts are in accordance with the amount of phenolics present in that extract.Leaves of Tetrastigma being rich in phenolics may provide a good source of antioxidant.

Biochemical changes in phenols,flavonoids,tannins,vitamin E,β-carotene and antioxidant activity during soaking of three white sorghum varieties

Objective:To investigate the changes in total phenols,flavonoids,tannins,vitamin E, β-carotene and antioxidant activity during soaking of three white sorghum varieties.Methods: The changes in total phenols,total ilavonoids,tannins,phenolic acids compounds,flavonoid components,vitamin E,P-carotene and antioxidant activity during soaking of sorghum grains were determined.Results:Total phenols,total flavonoids,tannins,vitamin E,P-carotene and antioxidant activity in raw sorghum were ranged from 109.21 to 116.70,45.91 to 54.69,1.39 to 21.79 mg/100 g,1.74 to 5.25,0.54 to 1.19 mg/kg and 21.72%to 27.69%and 25.29%to 31.97%,respectively. The above measured compounds were significantly decreased after soaking.p-Hydroxybenzoic acid,vanillic acid,syringic acid and cinnamic acid represent the major phenolic acids in Dorado variety.While ferulic acid,p-coumaric acid,gallic acid and caffeic acid represent the major phenolic acids in Shandaweel-6.On the other hand,protocatechuic acid represents the major phenolic acids in Giza-15.Regarding flavonoids components,Dorado was the highest variety in kampferol and naringenin while Shandaweel-6 was the highest variety in luteolin, apigenin,hypersoid,quercelin and christen.Finally,Giza-15 was the highest variety in catechin. Phenolic acids,flavonoid compounds and antioxidant activities were decreased after soaking. Conclusions:Sorghum varieties have moderate quantities from total phenols,total flavonoids, tannins,phenolic acids compounds,flavonoid components,vitamin E,P-carotene and antioxidant activity which decreased after soaking.

Studies on the Flavonoids and Antioxidant Activities in Leaves of Black Currant

The fresh leaves and oven dried leaves from three varieties of black currant (Brodtrop,liangye,Risager)were analysed for the total contents of flavonoids by spectrophotometric methods in terms of rutin equivalent.In addition,antioxidant activities of different addition amounts of extracts of black currant (Brodtrop)leaves in lard were measured by the Oven-Storage Test,and compared with the synthetic antioxidants.The results showed the contents of the flavonoids were very rich in the leaves of three varieties from black currant.Among them the leaves of Brodtrop had the highest contents of flavonoids followed by liangye and Risager.The total contents of flavonoids in fresh leaves reach 231 70 mg/100 g,170 01 mg/100 g and 78 07 mg/100 g respectively.In the same circumstance the oven dried leaves were 397 82 mg/100 g,275 89 mg/100 g and 169 73 mg/100 g.The extracts of the leaves from Brodtrop exhibited strong antioxidant activities on lard,which increased with the addition amount of the flavonoid extracts.The antioxidant activities decreased in the order of 0 02% quercetin >0 02% BHT(butylated hydroxy toluene)>0 40% extracts>0 20% extracts>0 10% extracts>0 05% extracts>0 02% extracts>control.

The antioxidant activity and hypolipidemic activity of the total flavonoids from the fruit of Rosa laevigata Michx

In the present work, the antioxidant activity in vitro and hypolipidemic activity of the total fla-vonoids (TFs) from the Rosa laevigata Michx fruit was evaluated, and the antioxidant effect in vivo was also discussed. The TFs exhibited a high scavenging effect on 2, 2-diphenyl-1- picrylhydrazyl (?DPPH) with IC50 values 0.01 mg/mL, and a stong reduce power in the test. Hyperli-pemic mice were intragastric administrated with TFs (25, 50 mg/kg/day) for 4 weeks, and fenofi-brate was used as the positive reference sub-stance. After the experiment, the levels of TC (total cholesterol), TG (triglyceride), LDL- C (low density lipoprotein-cholesterol) of the mice ad-ministrated with high-dose of TFs were mark-edly declined by 45.02%, 33.86% and 73.68%, re-spectively, while HDL-C (high density lipopro-tein-cholesterol) was significantly increased com-pared with model group. To investigate the hepatoprotective effect, histopathological assay, ALT (alanine aminotransferase), AST (aspartate aminotransefrase) and ALP (alkaline phosphatase) were also studied, and the results showed that TFs exhibited a favorable effect on liver protec-tion, of which the levels of ALT, AST and ALP were elevated by 55.85%, 29.15% and 25.68%, respectively. Furthermore, the TFs could sig-nificantly decrease the MDA (malondialdehyde) level and improve the levels of CAT (Catalas), SOD (superoxide dismutase), GSH (reduced glutathione), and GPX (glutathione peroxidase) compared with hyperlipemia mice. Our results suggested that TFs has a high antioxidant ac-tivity and hypolipidemic activity, which can be used as a potential medicine for cardiovascular diseases.

Quantification and analysis of anthocyanin and flavonoids compositions,and antioxidant activities in onions with three different colors

Onion（Allium cepa L.） is a very important vegetable crop widely cultivated throughout the world. In this study, we measured total anthocyanins and flavonols of onions of three colors. The fresh weight（FW） of total anthocyanins were（29.99±1.19）,（9.64±1.30） and（0.75±0.40） mg 100 g^–1 fruit in red, yellow and white onions, respectively. Likewise, the FW of total flavonoids were（111.10±5.98）,（36.64±3.59）, and 0 mg 100 g^–1 in red, yellow and white, respectively. Four types of anthocyanins（delphinidin 3,5-diglycosides, cyanidin 3,5-diglycosides, cyanidin 3-glycosides and cyanidin 3-（6′′-malonyl）-glucopyranoside） and two kinds of flavonoids（quercetin and quercetin 3-glycosides） were identified in two varieties（red and yellow bulb） of onions by HPLC/DAD-ESI/MS. The total polyphenol contents were also measured by means of Folin-Ciocalteu method. Moreover, all the concentrations of anthocyanins, flavonoids and polyphenols showed significantly positive correlations with antioxidant activities measured by DPPH˙, ABTS˙＋ and FRAP assays. This study provided information on anthocyanin and flavonoids compositions that will be useful for onion breeding.

Effects of drought stress on antioxidant enzyme,photosynthetic pigment and flavonoid pathway in two desert shrubs

Antioxidant enzyme activity, photosynthetic pigment content, and free malondialdehyde （MDA）, as well as flavonoid content and the key enzyme activity in the flavonoid pathway were determined in two desert shrubs, Caryopteris mongolica Bunge and Reaumuria soongorica （Pall.） Maxim. under drought stress. The free MDA content was enhanced during the experimental period, which may be an indicator of oxidative stress. Superoxide dismutase （SOD）, peroxidase （POD）, and ascorbate peroxidase （APX） activities in C. mongholica showed a significant increase during the experiment, but catalase （CAT） activity was slightly decreased. On the other hand, POD and APX activities showed a significant increase and SOD and CAT activity data had no significant changes in R. soongorica. APX, SOD, and CAT activities were higher in R. soongorica than in C. mongholica, but MDA content was lower, indicating that the lower values of MDA were attributed to higher activities of antioxidant enzyme in R. soongorica. Chlorophyll content decreased significantly in the two shrubs during the experiment, which indicated that there was a photoprotection mechanism through reducing light absorbance by decreasing pigments content. Caretonoids content increased in C. mongholica and decreased in R. soongorica. The ratio of Chla/Chlb decreased significantly but caretonoids/Chl revealed a significant increase in the two shrubs, which could be explained as no decrease of peripheral light-harvesting complexes and a higher tolerance to drought. Total flavonoid content and the activities of phenylalanine ammonialyase （PAL） and chalcone isomerase （CHI） showed different changes between C. mongholica and R. soongorica after treatment. These values decreased in R. soongorica and increased in C. mongholica except for PAL activity. However, anthocyanin content increased in the two shrubs, indicating that there was a different regulation response in the ftavonoid pathway in the two shrubs under drought stress, and anthocyanin should be an important antioxidant both in the shrubs. Our results demonstrated the different responses of antioxidant defense and drought tolerance ability between the two shrubs.

Investigation of in vitro antioxidant activity of dihydromyricetin and flavonoids rich extract from vine tea(Ampelopsis grossedentata)

Background:Vine tea from fermented Ampelopsis grossedentata leaves has been used as a herbal tea and folk medicine in the southern region of China for hundreds of years.The aim of this investigation was to analyze the total flavonoids found in vine tea,including three bioactive flavonoids,and the total phenolic contents in the aqueous methanol extracts of 10 vine tea samples.In addition,this study also aimed to examine the antioxidant activity of dihydromyricetin and vine tea’s flavonoid-rich extract.Methods:The total flavonoids and total phenolic content assay of extracts from vine tea were performed by ultraviolet-visible spectroscopy and epoch microplate spectrophotometer,respectively.Three bioactive flavonoids were quantified simultaneously using high performance liquid chromatography.The antioxidant activity of dihydromyricetin and vine tea’s flavonoid-rich extract was evaluated in vitro using six different methods.Results:Vine tea contained a large number of flavonoids,with dihydromyricetin as its main constituent.The flavonoid-rich extract exhibited a significant scavenging effect on superoxide anion radicals,and on 3-ethylbenzthiazoline-6-sulphonic acid and 1,1-diphenyl-2-picrylhydrazyl radicals.It also possessed definite activity in lipid peroxidation inhibition,ferric reduction,and the moderation of Fe2+ion chelation ability.There was a significant negative correlation between dihydromyricetin content and antioxidant activity in the vine tea samples,including superoxide anion radical scavenging activity(P=−0.754,P<0.05),lipid peroxidation inhibition activity(P=−0.759,P<0.05),ferric-reducing antioxidant power(P=−0.843,P<0.01),respectively.Dihydromyricetin played a dominant role in the antioxidant activities of the flavonoid-rich extract.Conclusion:Vine tea’s flavonoid-rich extract could be used as a new antioxidant source to safeguard against oxidative stress.

Phenolics,tannins,flavonoids and anthocyanins contents influenced antioxidant and anticancer activities of Rubus fruits from Western Ghats,India

Rubus fruits are rich in nutrition with a wide range of phytochemical and consumed by humans,but many of its wild varieties are not commercially useful.Phytochemical exploration of these wild fruits could improve the commercial usage of these Rubus species.This study focuses to analyze the phytochemical,antioxidant and cytotoxicity of three wild Rubus ellipticus,R.niveus and R.fairholmianus fruits comparatively,which has not revealed.The in vitro antioxidant studies indicated the ethyl acetate and methanol extracts of studied Rubus species competent in scavenging different stable and generated radical.The correlation and regression analysis also statistically supported the contents in the extracts could act against various radicals.Correlation between phytochemical constituent and radical scavenging activity found to be highly positive.The results acquired from this investigation revealed that they are equally competent and could be recommended as dietary supplements or as nutraceuticals.

Induced Accumulation of Polyphenolics and Flavonoids in Cyanobacteria under Salt Stress Protects Organisms through Enhanced Antioxidant Activity

Induced accumulation of polyphenolics and flavonoids in cyanobacterial strains grown under different salt concentrations is correlated with their growth under stress conditions and enhanced antioxidant activity. Plectonema boryanum, Hapalosiphon intricatus, Anabaena doliolum and Oscillatoria acuta grown for 21 days under different salt concentrations (80, 160, 240, 320 and 400 mM) in BG11 medium showed differential growth responses in terms of biomass, total protein, chlorophyll content, total content of polyphenol, flavonoid and carotenoid, accumulation of phenolic acids (gallic, caffeic, chlorogenic, ferullic and vanillic) and flavonoids (rutin and quercetin). Cyanobacterial extracts showed prominent free radical scavenging antioxidant activity (AOA) in terms of % DPPH discoloration. Highly significant (p < 0.05) and strong correlation was found between TPC and AOA (r = 0.974). Other positive but non-significant (p < 0.05) correlations were observed between AOA and gallic acid (r = 0.893) and AOA and caffeic acid (r = 0.931). Significant and strong correlation was also observed between gallic and caffeic acid (r = 0.973). Positive but lesser magnitude correlations were recorded between TPC and caffeic acid (r = 0.905), TPC and gallic acid (r = 0.920), gallic and vanillic acid (r = 0.916) and caffeic and vanillic acid (r = 0.814). An integrated combination of growth parameters, salt-induced accumulation of phenylpropanoids and stress-derived subsequent antioxidant property of cyanobacterial extracts is thought to provide evidence that secondary metabolic changes can act as the possible alternative mechanism to overcome stress-induced damages in cells.

Extraction and separation of total flavonoids from Flos Puerariae and its antioxidant activity

Objective To study the optimum extraction and separation process of total flavonoids in the flowers of Flos Puerariae and its antioxidative activity.Methods The total flavonoids were extracted with assistance of ultrasonic wave and the content was determined at 265 nm wavelength by Spectrophotometric method.Orthogonal experiment L9(34)was carried out to investigate the effects of concentration of solvent,the ratio of material to liquid,time length of extraction,and frequency of extraction on extraction results of total flavonoids from Flos Puerariae.The extracted solution was purified by petroleum ether and ethanol sequently.Under these conditions,the total flavonoids was eluted gradiently with mixed mobile phase of methanol-chloroform solution in the silica gel column system,and then determined by UV scanning and HPLC.Fenton reaction was used to produce and detect hydroxyl radicals(·OH),and pyrogallol system was used to produce and detect the superoxide radical anion(O2-·).Results The optimum conditions were as follows;using 40%(V/V)methanol as extractor with the ratio of material to liquid at 1∶30,and extracting for 2.5 h a time for 3 times.The extraction yield of total flavonoids was 13.6%.Six isoflavone compounds were isolated from the flowers of Flos Puerariae by the method of silica gel column chromatography.Antioxidative test results showed good performance of flavonoid scavenging capacity in both hydroxyl radical system and superoxide radical system and its IC50 was 7.65 μg·mL-1 and 0.18 mg·mL-1,respectively.Conclusions This study provided scientific basis for further development and utilization of Flos Puerariae and make preparation for later pharmacological research.

Extraction and Purification Process Optimization and Antioxidant Activity in vitro of Flavonoids in Amaranthus caudatus L.

[Objectives]To explore the optimal extraction and purification process of the flavonoids in Amaranthus caudatus L.and to study the antioxidant activity in vitro of the flavonoids in A.caudatus.[Methods]Taking A.caudatus as the raw material,flavonoids were extracted by alcohol extraction method,and AB-8 macroporous adsorption resin was selected for purification.The hydroxyl radical scavenging ability,DPPH radical scavenging ability,and O^2-radical scavenging ability were used as evaluation indicators,to explore the antioxidant activity in vitro of the flavonoids in A.caudatus.[Results]The optimal extraction process conditions of flavonoids in A.caudatus are:liquid-to-material ratio 40:1,extraction temperature 60℃,ethanol concentration 60%,ultrasonic power 320 W,extraction time 50 min.Under these conditions,the extraction yield of flavonoids in A.caudatus is(1.35±0.01)%.The optimal purification process conditions of flavonoids in A.caudatus are 2.5 g AB-8 macroporous adsorption resin,sample volume 5 mL,mass concentration of adsorption solution 1.60 mg/mL,pH value of adsorption solution 3.0,sample flow rate 3 BV/h,ethanol concentration in desorption process is 70%and the desorption flow rate is 3 BV/h.Under these conditions,the recovery rate reaches 88.35%±0.68%.[Conclusions]A.caudatus has a high content of flavonoids and has excellent free radical scavenging ability in vitro.This study is intended to provide important technical support for the research of flavonoid activity of A.caudatus and the development of functional products.

Response Surface Optimized Extraction of Flavonoids from Cacumen platycladi and Antioxidant Activities In vitro

[Objectives]To explore the optimal extraction process and the antioxidant activity of flavonoidsof Cacumen platycladi. [Methods]FCPwas obtained from C. platycladi by a new set extraction process of microwave-assisted extraction,freeze thawing,superfine crushingand freeze drying technology and purification. On the basis of single-factor tests,the quadratic regression parasitism model was established by the extraction amount of total flavonoids with microwave power,alcohol concentration,and liquid-to-solid ratio through the response surface methodology. [Results] The optimal extraction conditions were microwave power of 757 W,alcohol concentration of 69%,liquid-to-solid ratio of21∶ 1,with the optimal extraction yield of 15. 302 9 mg/g. Under the real conditions( microwave power of 800 W,alcohol concentration of69%,liquid-to-solid ratio of 21∶ 1) in our laboratory,the maximum yield of total flavonoids was 15. 9 mg/g,the results fitwell with the prediction of quadratic regression parasitism model. The good antioxidant activity has been determined byscavenging effect of FCP on 1,1-diphenyl-2-picrylhydrazyl( DPPH) radical and superoxide anion free radical with the scavenging yield of 70. 2% and 68. 8% respectively. [Conclusions]All results established a good foundation for furtherdevelopment of C. platycladi products.

Determination of Total Flavonoids and Its Antioxidant Ability in Houttuynia cordata

The total flavonoids of Houttuynia cordata are determined by UV-Vis spectrophotometry. The ex-traction condition of flavonoids from Houttuynia cordata includes: the extraction temperature is 70℃, solid-liquid ratio is 1:20, solvent is 80% ethanol, extraction time is 65 min. We studied the antioxidation of flavonoids in Houttuynia cordata, and results showed that flavonoids had strong reducing capacity, hydroxyl free radical scavenging activity and the superoxide anion radical scavenging ability, thus can provide a basis for the development of natural antioxidants.