Flavonoid Content Of Ethanol Extract Research Articles

Total Phenolic, Flavonoid, and LC-MS Analysis of the Ethanolic Extract of Matoa (Pometia pinnata) Leaves from Kudus, Central Java, Indonesia

Matoa (Pometia pinnata) is a plant used as a floral identity in Indonesia, especially in Papua. Local people use boiled water from matoa leaves, which is believed to treat hypertension. Matoa leaves are traditionally used as a therapeutic agent for burns and wounds in Indonesia. Phytochemical screening of matoa leaf extract contains secondary metabolite compounds, including flavonoids, steroids, tannins, and saponins. So far, many of these activities have been reported from the polyphenol group. This research aimed to identify the phytochemical composition of matoa leaves from Kudus in the ethanolic extract using LC-MS. The total phenolic content of ethanol extract using the Folin Ciocalteu method was 35.689 ± 0.726 mg GAE/g extract. The total flavonoid content of ethanol extract using the AlCl3 colorimetric method was 1.384 ± 0.012 mg QE/g extract. Twelve compounds could be identified in the ethanol extract of matoa leaves. The phenolic compounds were vanillin, p-hydroxybenzaldehyde, p-Coumaroyl glycolic acid, syringic acid, gallic acid, phenol, and vanillic acid. The flavonoid compounds were identified as epigallocatechin and apigenin -7-O-diglucuronide. The organic compound was identified as jasmonic acid. The aromatic compound was identified as benzene. Besides, tannin compounds were also identified. The major compounds in matoa leaves from Kudus, Central Java, are vanillin, phenol, and benzene.

Antioxidant Assay and Total Flavonoid Determination of Ethanolic Extract of Walnut (Canarium indicum L.) Leaves and Its Fractions

Antioxidants are compounds that inhibit free radicals. Many plants have antioxidant activity because they contain antioxidant compounds such as flavonoids. This study aimed to evaluate the antioxidant activity, phytochemical contents, total flavonoid content and to establish the relationship of total flavonoid content and antioxidant activity of extract and fractions of walnut (Canarium indicum L.) leaves. Antioxidant activity of ethanolic extract, n-hexane fraction, ethyl acetate fraction, and ethanolic-water fraction of walnut leaves was examined by using the DPPH method and determination of total flavonoid content was determined spectrophotometrically. The results showed that antioxidant activity of ethanolic extract, n-hexane fraction, ethyl acetate fraction, and ethanolic-water fraction based were 25.294 ± 0.055; 175.245 ± 0.4999; 20.135 ± 0.009; and 28.806 ± 0.0424 μg/ml, respectively. The phytochemical content of ethanol extract of walnut leaves are saponins, flavonoids, tannins, and polyphenols. The total flavonoid content of ethanolic extract, n-hexane fraction, ethyl acetate fraction and ethanolic-water fraction were 2.624 ± 0.012; 0.499 ± 0.023; 3.846 ± 0.006; and 1.596 ± 0.006 gram quercetin equivalent/gram extract, respectively. Correlation between antioxidant activity and total flavonoid content revealed that 63.2 % of antioxidant activity was influenced by the presence of flavonoid compounds.

Determination of Total Flavonoid Content from Ethanol Extract and Various Paliasa (Kleinhovia Hospita L.) Leaf Fractions on its Potential as an Antioxidant

Paliasa (Kleinhoivia hospita L.) is a plant of the Sterculiaceae family which is known to have potential as an antioxidant. This study aims to determine the total flavonoid content of ethanol extract and various fractions of paliasa leaves on their potential as antioxidants. Samples were macerated with 70% ethanol for 24 hours at room temperature. The ethanol extract obtained was then evaporated at 50 o C to produce a viscous extract which was then fractionated using n -hexane, dichloromethane and water as solvents. The content of chemical compounds from the ethanol extract of paliasa leaves are alkaloids, flavonoids, saponins, phenols and tannins. The content of chemical compounds from the n -hexane fraction is tannins. The content of chemical compounds from the dichloromethane fraction are flavonoids, phenols and tannins. The content of chemical compounds from the water fraction are alkaloids, saponins, phenols and tannins. Tests for total flavonoid compounds found in the ethanol extract and dichloromethane fraction using rutin as a comparison at λ max 419 nm were 3.10% and 3.73%. Antioxidant activity testing using the 1,1-Diphenyl-2-Picrilhydrazil (DPPH ) method showed that the ethanol extract and fraction ( n -hexane, dichloromethane and water) had an IC of 50 166.55 µg/mL, 351.19 µg/mL, 85 .87 µg/mL, and 226.52 µg/mL, while gallic acid comparator has a very strong antioxidant activity with an IC50 value of 10.75 µg/mL

Combination of ethanolic extract on total flavonoid Centella asiatica L. leaves and Imperata cylindrica L. roots with UV-VIS spectrophotometric method

Background: Flavonoids are widely employed as phytomedicines and as secondary metabolites generated by plants, where they serve key roles in plant physiology. Antioxidant, anti-inflammatory, anticancer, antibacterial, antifungal, and antiviral activities are only a few of the potential biological effects of flavonoids. The discovery of medicinal plants containing flavonoid chemicals is potential as a supportive and preventative treatment, notably for COVID-19 which has caused a pandemic in several countries, including Indonesia.Objective: This study aimed to determine the total flavonoid content in the ethanolic extracts of C. asiatica leaves and Imperata cylindrica roots to find the potential of flavonoid-rich plants as an alternative source of COVID-19 treatment.Methods: The ethanolic extracts from the combination of C. asiatica leaves and I. cylindrica roots (with five combination ratios) were tested for total flavonoid content using the UV-Vis Spectrophotometry method. The total flavonoid content of the extract combination was analyzed using a one-way ANOVA test.Results: The total flavonoid contents of the combination of C. asiatica leaf and I. cylindrica root extracts at a ratio of 1:1, 2:3, 3:2, 4:1, and 1:4 were 45.88 ± 0.08, 42.14 ± 0.08, 40.52 ± 0.08, 66.28 ± 0.08, and 40.88 ± 0.13 mg/g EQ, respectively. The homogeneity with Levenes test obtained a p-value of 0.303. The one-way ANOVA exhibited the p-value of F-test statistics Conclusion: The total flavonoid contents of ethanolic extracts from C. asiatica leaves and I. cylindrica roots are at a ratio of 4:1 > 1:1 > 2:3 > 1:4 > 3:2. The high total flavonoid content plays a role in increasing anti-inflammatory and immunomodulatory activities in COVID-19 patients.Keywords: Total flavonoid content, C. asiatica, I. cylindrica, UV-Vis Spectrophotometry, COVID-19

ANALYSIS OF TOTAL FLAVONOID LEVEL AND ANTIOXIDANT ACTIVITY TEST PURPLE CABBAGE (BRASSICA OLERACEA L. VAR. CAPITATA F. RUBRA) AND WHITE CABBAGE (BRASSICA OLERACEA L. VAR. CAPITATA F. ALBA) ETHANOL EXTRACT USING DPPH METHOD (1,1-DIFENIL-2-PIKRILHIDRAZIL)

Antioxidants are compounds that are needed by the body to protect the body from free radical attacks that can trigger the emergence of degenerative diseases. One of the compounds that has free radical scavenger activity by inhibiting Reactive Oxygen Species (ROS) is flavonoids found in purple cabbage and white cabbage. This study aims to determine the total levels of flavonoids expressed as quercetin equivalent (EK) and antioxidant activity using the DPPH method (1,1-diphenyl-2- picrylhydrazyl). Identification of flavonoid compounds by Willstater test and determination of total flavonoid levels using spectrophotometry, AlCl3 reagent. Flavonoid levels were calculated using linear regression equations. Qualitative test for the presence of antioxidant activity using TLC and antioxidant activity test using the DPPH method with the parameter value of ES50. The qualitative test results showed that the ethanol extract of purple cabbage and white cabbage contained flavonoids. The total flavonoid content of ethanol extract of purple cabbage was 5.17% w/w (EK) and ethanol extract of white cabbage was 3.84% w/w (EK). Qualitative test with TLC showed antioxidant activity. The standard antioxidant activity values ​​of quercetin, ethanol extract of purple cabbage and white cabbage were 2.138±0.064 µg/mL; 154.445±0,999 µg/mL and 373.546±1.336 µg/mL. The antioxidant activity of purple cabbage is weak and white cabbage is very weak.

PENENTUAN KADAR FLAVONOID TOTAL DAN NILAI SPF EKSTRAK ETANOL DAUN BUAS-BUAS (Premna serratifolia L.) ASAL KABUPATEN MELAWI PROVINSI KALIMANTAN BARAT

ABSTRACT
 
 Premna serratifolia L. leaves contain flavonoids, saponins, polyphenols, and terpenoids,
 potentially act as sunscreens. The purpose of this study was to determine the flavonoid content and
 SPF (Sun Protection Factor) ethanol extract of Premna serratifolia L. leaves from Melawi Regency,
 West Kalimantan Province using UV-Vis spectrophotometer. The Premna serratifolia L. leaves were
 extracted by maceration using 70% ethanol solvent, then the filtrate obtained was concentrated with a
 rotary vacuum evaporator to obtain a thick extract. The extract was determined for its flavonoid
 content using UV-Vis spectrophotometer at a wavelength of 439 nm, and the SPF value was
 determined at a concentration of 25, 50, 75, and 100 ppm with a UV-Vis spectrophotometer at a
 wavelength of 290-320 nm. The SPF value was calculated and analyzed descriptively using the
 Mansur method. The result showed that the average flavonoid content of ethanol extract of Premna
 serratifolia L. leaves was 3.70±0.02% calculated as quercetin. The SPF EEDB values obtained from
 variations in concentrations of 25, 50, 75, and 100 ppm respectively were 19.95±0.02; 30.08±0.01;
 34.58±0.14; and 38.28 ± 0.12, where the SPF value is included in the ultra protection category.
 
 Key words: Premna serratifolia L. leaves, flavonoid content, SPF, UV-Vis Spectrophotometer

Penentuan Kadar Flavonoid Total Ekstrak Etanol Jamur Susu Harimau (Lignosus rhinocerus)

ABSTRACT 
 Tiger milk mushroom (Lignosus rhinocerus) is a plant that has traditionally been used as a medicine in the interior of West Kalimantan, especially in Kapuas Hulu. One of the phytochemical constituents contained is flavonoids (flavones and flavanones). This study aims to determine the total flavonoid content of ethanol extract of tiger milk mushroom. The simplicia of tiger milk mushroom was macerated using 96% ethanol. Phytochemical screening for the presence of flavonoids the extract using magnesium and amyl alcohol powder. Determination of total flavonoid content in ethanol extract of tiger milk mushrooms was carried out by UV-Vis spectrophotometry using the colorimetric method (AlCl?) at ? 410 nm and expressed as total flavonoids in quercetin equivalent. The results showed that total flavonoid content of ethanol extract is 33.041 mgEQ/g extract. Ethanol extract of tiger milk mushroom which contains flavonoids is potential as a source of natural antioxidants and potential to be developed in medicinal and cosmetic products.
 Keywords: Colorimetry, tiger milk mushroom, total flavonoid content.

Phytochemical Evaluation and In-vitro Antioxidant Potential of whole plant of Caralluma adscendens

The current line of investigation was focused at perusing the presence of phytochemical constituents, investigation of total phenol and flavonoid content, the antioxidant potential of various extracts of Caralluma adscendens whole plant using various in-vitro assays. The dried plant powder was extracted with various solvents based on polarity (Pet ether, Chloroform, Ethyl acetate, Ethanol and Aqueous) by hot continuous extraction in Soxhlet's apparatus and Extracts were dried. Phytoconstituents present in each extract was examined by performing preliminary phytochemical screening. Total Phenolic Content (TPC), Total Flavonoid Content (TFC) and Antioxidant potential for crude extracts were studied by DPPH, nitric oxide scavenging and FRAP methods. The total phenolic content and flavonoid content of Ethanolic extract of plant was found to be 80.08±0.629mg and 70.88±1.170mg of GAE and Quercetin equivalents respectively. The Ethanolic extract exhibited potent antioxidant activity as determined by 2,2-diphenyl-1-picrylhydrazyl(DPPH), nitric oxide scavenging and ferric reducing antioxidant power assays(FRAP) than the other extracts. The IC50 values for the Ethanolic extract of Caralluma adscendens was found to be 214.765±0.224 µg/ml and 215.928±0.506µg/ml by DPPH and nitric oxide scavenging assays respectively.

Optimization of total flavonoid content of ethanolic extract of Persicaria pulchra (Bl.) Soják for the inhibition of α-glucosidase enzyme

Objectives. There has been a rapid increase in the number of diabetic patients since the past few decades in developed and developing countries. This rapid increase is accompanied by alarming costs of treatment. α-Glucosidase inhibitors are one of the most effective drugs employed for the reduction of postprandial hyperglycemia to manage Type 2 diabetes mellitus. Additionally, flavonoids, a group of natural substances, which are widely distributed in plants and possess variable phenolic structures, exhibit outstanding hypoglycemic activity and are considered as potential α-glucosidase inhibitors. In Vietnam, Persicaria pulchra (Bl.) Soják (P. pulchra) is employed in traditional medications. It possesses high flavonoid contents and its anti-diabetes ability has been hypothesized, although it has attracted less attention for investigation. Hence, the aim of this study is to optimize the condition of the P. pulchra extract to obtain the highest total flavonoid content and measure the bioactivities of P. pulchra, such as the anti-α-glucosidase and antioxidant activities.Methods. The effects of the extracting conditions, including the temperature, extraction time, liquid-to-solid ratio (LSR), and ethanol (C2H5OH) concentration, on the total flavonoid content are investigated via experiments and analyzed by the response surface methodology (RSM). Concurrently, the optimal extraction also determines the anti-α-glucosidase and antioxidant activities.Results. The optimal extraction condition for the highest flavonoid content (530 mg quercetin/g) is determined in 60 min, at 53°C, with LSR of 9.46 g/g and C2H5OH concentration of 62%. Moreover, the optimal plant extract exhibits good α-glucosidase inhibition with a half-maximal inhibitory concentration (IC50) of 22.67 mg/mL, compared to the positive control (acarbose −7.77 g/mL). Additionally, P. pulchra is proposed to be a potential antioxidant with an IC50 of ~12.68 µg/mL.Conclusions. The study confirmed the optimal extraction condition of P. pulchra that will obtain the highest total flavonoid content and revealed the potentials of P. pulchra in α-glucosidase inhibition and antioxidation.

Determination of the phytochemical screening, total polyphenols, flavonoids content, and antioxidant activity of soursop leaves (Annona muricata Linn.)

Annona muricata Linn. (soursop) plant is a medicinal plant that has been utilized in folk medicine for treatment of infectious and inflammatory diseases. This study aimed to determine the phytochemicals content, total phenolic and flavonoid contents and antioxidant activities of A. muricata leaves. Antioxidant activity was performed via 2, 2’-azino-bis(3- ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenyl- 1-picrylhydrazyl (DPPH) radical scavenging assays. The phytochemical was extracted separately with distilled water and 96% ethanol by maceration. The results show that a wide variety of pharmacologically active compounds such as alkaloids, coumarins, tannins, flavonoids, carbohydrates, phenols, terpenoids, saponins were present in the leaves of A. muricata. The total phenolic and flavonoid content of ethanol extract in A. muricata leave achieved 609.08±5.82 mgGAE/g and 209.52±1.88 mgQE/g, respectively. The antioxidant activity of the ethanol extract of A. muricata was correlated with total phenolic and flavonoid content with values IC50 of 20.75±0.28 μg/ml, 12.84±0.21 μg/ml for DPPH and ABTS scavenging activity, respectively.

In vitro free radical scavenging and antidiabetic activity of aqueous and ethanolic leaf extracts: a comparative evaluation of Argyreia pierreana and Matelea denticulata

BackgroundOxidation is believed to play a vital role in the pathogenesis of diabetes mellitus by lipid peroxidation; DNA and protein damage leads to the development of vascular complications like coronary heart disease, stroke, neuropathy, retinopathy, and nephropathy. The herbal preparations are complementary and alternative medicines to allopathic drugs which are believed to cause adverse events. Therefore, the current study was aimed to identify the novel plants, which belong to the genera Argyreia (Argyreia pierreana (AP)) and Matelea (Matelea denticulata (MD)), and assess the aqueous and ethanolic leaf extracts for in vitro antioxidant and antidiabetic potential by DPPH, OH•, superoxide, and glucose uptake and gene expression (GLUT-4 and PPARγ) studies using the L-6 cell line respectively.ResultsThe preliminary scrutiny revealed the presence of polyphenols, flavonoids, terpenoids, steroids, tannins, alkaloids, and glycosides. The total phenolic and flavonoid contents of ethanolic extracts were found higher than those of aqueous extracts. The ethanolic extracts exhibited the superior antioxidant capacity when compared with aqueous extracts. However, the ethanolic extract of MD was shown superlative glucose uptake activity (72.54%) over control (0.037%) and GLUT-4 and PPARγ gene expressions (1.17 and 1.20) in term of folds respectively over cell control (1.00).ConclusionThe ethanolic leaf extracts of both plants showed significant in vitro antioxidant and antidiabetic activities compare to aqueous extracts. The Matelea denticulata ethanolic leaf extract exhibited superior activity. This superior activity might be due to their higher phenolic and flavonoid content. However, further approaches are needed to define these activities.

Essential Oil and Ethanol Extract of Oregano (Origanum vulgare L.) from Armenian Flora as a Natural Source of Terpenes, Flavonoids and other Phytochemicals with Antiradical, Antioxidant, Metal Chelating, Tyrosinase Inhibitory and Antibacterial Activity.

Origanum vulgare is used in Armenian cuisine as well as in folk medicine. The aim of this investigation was to determine the peculiarities of the chemical composition of Armenian flora's oregano essential oil (EO) and ethanol extract (EE) and to characterize mainly antioxidant and antibacterial properties in vitro. EO of plant aerial parts was extracted by the hydro-distillation method, and the composition was analyzed by gas-chromatography (GC). EE was prepared using ethanol as a solvent. Antioxidant, antibacterial and other biological activity of EO and EE was determined using appropriate methods. The terpenes were found to be the greatest part of oregano EO (β-caryophyllene epoxide - 13.3 %; β- caryophyllene -8.2 %; ο-cymene - 5.2 %). The flavonoid content of EE was 3.9±0.7 mg g-1 catechin equivalents. Antiradical activities of EO and EE expressed with half-maximum inhibitory concentrations were 1057 µg mL-1 and 19.97 µg mL-1. The antioxidant index in the case of using extract (1000 µg mL-1) was 77.3±1.5 %. The metal chelating activity of EE was 74.5±0.2 %. The tyrosinase inhibitory activities of EO, EE and arbutin were 26.5±0.3 %, 6.5±0.2 % and 50±0.1 %, respectively. Both EO and EE of oregano were able to suppress the growth of testmicroorganisms including clinical pathogen isolates, but have moderate antimicrobial activity. EO antibacterial activity against ampicillin-resistant Escherichia coli was similar to the activity against non-resistant strain. EE was not active against ampicillin-resistant E. coli in contrast to non-resistant one. The results indicate high antioxidant and moderate antibacterial as well as high antiradical, metal chelating, tyrosinase inhibitory activity of oregano EO and EE, which can be used as a natural source of terpenes, flavonoids and other phytochemicals in medicine, pharmaceutics, cosmetics and food industry. EO has antibacterial activity also against ampicillin-resistant E. coli.

THE EFFECTIVENESS OF TOTAL FLAVONOID EFFECT OF ETHANOL EXTRACTS OF NANGKA STONE (Artocarpus heterophyllus Lam) ON HEALING OF PASS Wounds IN BROILER CHICKEN (Gallus domesticus)

Nangka (Artocarpus heterophyllus Lam) merupakan tumbuhan lokal yang terdapat di berbagai daerah di Indonesia. Pohon nangka ini biasanya dimanfaatkan sebagai obat tradisional. Penelitian ini bertujuan untuk menguji ekstrak etanol kulit batang nangka terhadap penyembuhan luka sayat pada kulit ayam broiler dan penetapan kadar flavonoid total menggunakan metode kalorimetri.Penelitian ini dimulai dengan identifikasi tumbuhan, pengambilan kulit batang nangka, pengolahan simplisia kulit batang nangka, pembuatan ekstrak etanol kulit batang nangka (Artocarpus heterophyllus Lam), pengukuran kandungan flavonoid total ekstrak etanol kulit batang nangka, penyiapan hewan uji, penyayatan luka pada kulit ayam, uji efektivitas flavonoid total ekstrak etanol kulit batang nangka (Artocarpus heterophyllus Lam) terhadap penyembuhan luka sayat pada ayam broiler (Gallus domesticus), analisis data. Hasil penelitian menunjukkan bahwa pemberian ekstrak etanol kulit batang nangka (Artocarpus heterophyllus Lam) terhadap penyembuhan luka sayat pada kulit ayam broiler (Gallus domesticus) memberikan efek daya penyembuhan yang lebih baik dari kontrol negatif. Hasil pengolesan 4 kali dalam 24 jam paling cepat memberikan efek penyembuhan terhadap luka sayat pada kulit ayam broiler (Gallus domesticus). Berdasarkan hasil statistik terdapat 86,1% flavonoid yang mempengaruhi luas kurva dan mempengaruhi kesembuhan luas luka sayat pada ayam.

Study on antibacterial and flavonoid content of ethanolic extract of Punica granatum (pomegranate) peel

Pomegranate is known for it's many health benefits. These benefits are due to the biological active compounds which are present in the pulp as well as in the peel of the pomegranate. The active compounds from the peel were obtained using cold percolation method using ethanol as solvent. Antibacterial activity of pomegranate peel extract (PPE) was studied on E. coli, E. coli NCIM 2065, Salmonella typhi, Salmonella paratyphi B, Pseudomonas aeruginosa, Proteus mirabilis, S. aureus, S. aureus NCIM2079, Shigella flexneri, Lactobacilus casei var shirota by agar well diffusion method. All organisms were sensitive to the extract with inhibitory concentration ranging from 25mg/mL-100mg/mL except Lactobacilus casei var shirota which was resistant to even 100mg/mL concentration of PPE. Flavonoid content of the extract was found to be 10mg quercetin equivalent/g of extract.

Antioxidant activity, determination of total phenolic and flavonoid content of Muntingia calabura L. Extracts

Muntingia calabura L. leaves were contained alkaloids, saponins, phenolic, flavonoids, and tannin. Phenolic and flavonoids compound had antioxidant activity. The present study aims to determine the antioxidant activity, determination of total phenolic and flavonoid content of ethanol extract of Muntingia calabura L. leaves and its fractions. Muntingia calabura L. leaves were macerated with 96% ethanol and then evaporated until ethanol extract was obtained. The ethanol extract was dissolved into water and then partitioned with n hexane and ethyl acetate to obtain the n hexane fraction, ethyl acetate fraction and water fraction. Determination of antioxidant activity of extracts and fractions was performed by free radical capture measurement method by 1,1-diphenyl-2-picrylhydrazyl (DPPH) in vitro . Vitamin C was used as a positive control with IC 50 value of 25.74 µg/mL. The total phenolic and flavonoid content were determined using the colorimetric method using standard gallic acid for total phenolics and standard quercetin for flavonoid content. The results showed that ethyl acetat fraction showed the highest antioxidant activity with IC 50 79.37 μg/mL value compared to n hexane fraction (101.36 μg/mL), ethanol extract (126.47 μg/mL), and water fraction (129.85 μg/mL). The ethyl acetate fraction contains the highest total phenolic of 510.57 mg GAE/g extract compared to ethanol extract (311.10 mg GAE/g extract), water fraction (292.74 mg GAE/g) extract, and n hexane fraction (103.95 mg GAE/g extract). The ethyl acetate fraction contained the highest flavonoid content of 76.32 mg QE/g extract compared to ethanol extract (39.63 mg QE/g extract), water fraction (14.29 mg QE/g extract) and n hexane fraction (3.30 mg QE/g extract). Total phenolic and total flavonoid levels were positively correlated with antioxidant activity

Comparative Antioxidant Potential of Bark and Leaves of Terminalia arjuna (Roxb) Wight & Arn from Himachal Pradesh

The present study aimed to compare antioxidant activities, total phenolic and flavonoid content present in leaves and bark of Terminalia arjuna and check whether there is any correlation between phenolic content and flavonoid content with antioxidant activities or not. Phytochemical screening of ethanolic extract of leaves and bark revealed the presence of phenols, flavonoids, tannins, carbohydrates, glycosides, saponin, phytosterols and phytosteroids. Total phenolic content was found to be higher in bark (272.71±3.18 mg/g gallic acid equivalents) as compared to that of leaves (95±3.11 mg/g gallic acid equivalents). Similarly, flavonoid content of ethanolic extract of bark was found to be higher (203.95±5.13 mg/g rutin equivalents) than that of leaves (87.625±4.28 mg/g rutin equivalents). DPPH activity of ethanolic extract of bark (IC50-17.41 µg/ml) was more than that of leaves (IC50-20.22µg/ml). FRAP activity of bark (IC50- 4.781 µM Fe (II) equivalents) is more than that of leaves (IC50-7.572 µM Fe (II) equivalents). Nitric oxide (NO) scavenging activity of bark (IC50-12.87 µg/ml) was higher than that of leaves (IC50-13.91 µg/ml).The present study clearly showed that there is a correlation between total phenolics, flavonoid contents and antioxidant activity of leaves and bark of T. arjuna. The phenolic compounds and flavonoids could be major contributor to antioxidant activity of T. arjuna. Keywords: Terminalia arjuna, DPPH, FRAP, NO, IC50, Antioxidants

Antioxidant and angiotensin converting enzyme (ACE) inhibitory activities of ethanol extract and pure flavonoids from Adinandra nitida leaves

Context: Adinandra nitida Merr. ex. H.L. Li (Theaceae) is an indigenous plant in south China. Its leaves have been reported to have many curative effects such as reducing blood pressure, as well as antibacterial, antioxidant, and analgesic properties, which could be used in foods and medicines.Objective: The antioxidant and angiotensin converting enzyme (ACE) inhibitory activities of the main flavonoids and ethanol extract (EE) of A. nitida leaves were investigated for the first time.Materials and methods: The main flavonoids of A. nitida leaves (camellianin A, camellianin B) were prepared and their contents in EE were determined by HPLC. The antioxidant activities of the samples were measured by DPPH radical scavenging assay and Rancimat test. The ACE inhibitory activities of the samples were carried out by using an assay kit with hippuryl-glycyl-glycine as substrate.Results: The contents of camellianin A, camellianin B and apigenin in EE were determined as 41.98, 2.67, and 1.73%, respectively. The antioxidant activities of the flavonoids were far lower than that of EE in DPPH radical scavenging and Rancimat assays. However, the ACE-inhibitory activities of camellianin A, camellianin B and apigenin were higher than that of EE.Discussion and conclusion: The flavonoid content of EE was more than 45%. The high activities of EE in DPPH scavenging and Rancimat assay could be mainly attributed to compounds other than flavonoids. However, the ACE-inhibitory activity of EE could be mainly attributed to the presence of the flavonoids.