Variation in Contents of Total Phenolics and Flavonoids and Antioxidant Activities in the Leaves of 11 Eriobotrya Species

Aims: This study aimed to investigate the total phenolic and flavonoid content and DPPH free-radical scavenging activity of Vernonia amygdalina planted in Mekong Delta. The optimized conditions for maceration of pandan leaves included drying method, ratio of pandan leaf powder-to-solvent, and extraction time.
 Methodology: The fresh pandan leaves were divided into two equal portions, subjected to different drying methods: shade and oven drying. The dried leaf powder was macerated in ethanol at room temperature. The maceration was conducted with 3 different ratios of pandan leaf powder-to-solvent (w/v) (1:10, 1:15 and 1:20), and the extraction time was 1, 2 and 3 days. The total flavonoid content was determined using aluminum chloride method whereas the total phenolic content was assessed using Folin-Ciocalteu assay. Meanwhile, the antioxidant activity of the plant extracts was quantitatively evaluated using DPPH test.
 Results: The results indicated that the best conditions for maceration of pandan leaves were 1:10 shade-dried leaf powder-to-solvent ratio in 1-day extraction time. Accordingly, the total flavonoid and phenolic content was found to be the highest value of 130.02 ± 2.24 mg QE/g of dried extract and 100.67 ± 1.76 mg GAE/g of dried extract (p < 0.05), respectively. The lowest IC50 of DPPH free-radical scavenging activity of pandan leaf extract was found to be 0.90 ± 0.02 mg/mL (p < 0.05). In addition, the Pearson’s correlation coefficient between IC50 of DPPH free-radical scavenge activity and total flavonoid content was R2 = 0.74 compared to that of phenolic content with the value of R2 = 0.69, indicating that the IC50 of DPPH free-radical scavenge capacity of pandan leaves was influenced chiefly by flavonoid compounds.
 Conclusion: There was a significant difference in phenolic and flavonoid content and DPPH free-radical scavenging activity between shade-dried and oven-dried pandan leaf extracts.

Purpose: To evaluate the total phenolic and flavonoid contents of Mentha spicata (MS) leaves aqueous extracts obtained from different regions (El-Oued, Tebessa and El-Tarf) of Algeria, as well as their in vitro antioxidant and antidiabetic activities.
 Methods: Aqueous extracts were obtained from the air-dried leaves of MS by maceration followed by filtration and evaporation using a rotary evaporator. Folin-Ciocalteu and Aluminium chloride colorimetric techniques were used to determine the total phenolic and flavonoid contents, respectively. The radical DPPH, ABTS, and FRAP tests were used to determine their antioxidant activities, while the in vitro inhibition percentages of α-amylase and α-glucosidase enzymes were used to assess the anti-diabetic activity.
 Results: The El-Oued's extract exhibited the highest total phenolic content (108.94 mg GAE/g dry extract (DE)), while the highest total flavonoid content (0.039 mg QE/g DE) was found in El-Tarf's extract. The radical DPPH and FRAP scavenging activity of the El-Oued extract exhibited the highest inhibition activities (IC50 = 102.5 and 289.5 μg/mL), respectively, while the ABTS inhibition activity of the El-Tarf extract exhibited a maximum IC50 value of 111 ± 2.8 μg/mL. The MS extract of the El-Oued region had the highest α-amylase and α-glucosidase enzyme activities with IC50 values of 121.4 and 216.9 μg/mL, respectively.
 Conclusion: The leaves of Mentha spicata exhibit high phenolic and flavonoid contents, along with significant antioxidant and antidiabetic properties. This study reveals that Mentha spicata flavonoid and phenolic contents as well as other properties vary by region.

Solanum anguivi Lam. is an ethnomedicinal plant. Local traditional practitioners believe that it reduces the risk of diabetes and atherosclerosis diseases. The present study was intended to conduct qualitative phytochemical analysis, determine the total flavonoid and phenolic contents, estimate the antioxidant capacity and antibacterial activities of the extracts of the fruits of this plant. The antioxidant activity was determined by analyzing the radical scavenging activity (RSA) using 2,2-diphenyl-1-picryhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. The antibacterial activities were determined by the agar well diffusion method. Qualitative phytochemical screening of the crude extracts obtained from the fruits of the plant indicated the presence of alkaloids, flavonoids, phenols, glycosides, steroids, terpenoids, saponins and tannins. The highest total phenolic and total flavonoid content were obtained in the ethanol extract of the fruits, followed by dichloromethane and n-hexane extract. The total phenolic content (in gallic acid equivalents, GAE) ranged from 113.3 to 202.72 mg GAE/g. The total flavonoid content (in catechin equivalent, CE) varied from 61.72 to 142.64 mg (CE)/g. All fruit extracts of S. anguivi exhibited antioxidant activity as revealed by DPPH and FRAP assays. The DPPH RSA (% inhibition) of the fruit extract varied from 35.11 to 80.13. The total phenolic and Flavonoid contents showed alinear correlation with RSA. Furthermore, all fruit extracts showed antibacterial activity against gram-positive and gram-negative bacteria varying from 12.5 to 16.75 mm. The result showed that the extracts of the plant exerted stronger bactericidal effect on gram-positive bacteria than on gram-negative bacteria. Supplemental data for this article is available online at https://doi.org/10.1080/13102818.2021.1993087 .

The sweet chestnut fruit has always had great importance in the southern European countries. Chestnut production is an important source of income and a crop of high environmental value thanks to its role in soil protection. It is also a good food with enormous potential for various aspects of health because of its nutritional qualities. The quality of sweet chestnuts is affected by various factors, such as climatic conditions and cultivation inputs. It is very important to recognize the impacts of climate on chestnut fruits, to improve our current understanding of climate–chestnut interconnections. The current study investigated and compared the antioxidant activity and the total phenolic and flavonoid contents of different cultivars of chestnuts grown in different geographic areas of northwest Spain. The results obtained with three antioxidant capability assays (DPPH, ABTS and FRAP assays) were highly correlated. All the samples had high antioxidant capacity and high total phenolic and total flavonoid contents, which depended both on cultivar and growth region. Ventura variety, harvested in the coldest environments, presented the highest values of antioxidant activity (IC50DPPH = 34.5 g/L), total phenolic content (131.84 mg equivalent of gallic acid/100 g FW) and total flavonoids (7.77 mg eq. catechin/100 g). The variations in the antioxidant capacity, total phenolic and total flavonoid contents of different cultivars, and their associations with climatic environmental factors, revealed the significant impacts of these factors on the synthesis of specialized metabolites and on the nutraceutical potential of chestnuts. The results can provide valuable information for selection of the cultivar and the cultivation conditions of the chestnut, in order to obtain chestnuts with high-quality bioactive characteristics.

Phenolic and flavonoid contents in plants play a great role in scavenging free radicals in the body and act as antioxidants; thus making their determination very vital. Total phenolic and flavonoid contents of the methanol extract of Voacanga africana root bark and its fractions (n-hexane, ethyl acetate and n-butanol) were carried out in this study. The total phenolic content was determined by using Folin-Ciocalteau assay while the the total flavonoid content was determined by the aluminium chloride colorimetric assay method. The result obtained showed that n-hexane fraction of the plant exhibited the highest (116.607±95.13 mgGAE/g) total phenolic content (TPC) at all concentrations followed by ethyl acetate fraction of the plants. The highest total flavonoid content across concentrations (300, 250, 200, 100, 50 and 25 μg/ml) was exhibited by n-hexane fraction (467.143±44.22 mg QE/g). From the results, it was concluded that n-hexane fraction of V. Africana root bark exhibited the highest total phenolic and total flavonoid contents at all concentrations (ppm), followed by ethyl acetate. It could be deduced that V. africana root bark possesses phenolic and flavonoid contents depending on the type of extract or fraction; thus justifying its folkloric use in the treatment of diseases.Keywords: Phytochemicals, Phenols, Flavonoids, Voacanga africana, Root bark, Fraction

BACKGROUND As the longevity of human lives has increased, the geriatric population is increasing demonstrating more number of oral candidal infections due to decreased immunity. Natural products are being investigated to be used to treat oral candidiasis in place of synthetic drugs in selective geriatric cases. Propolis is one such natural product, which is time tested and developed by nature as an antimicrobial agent. Its toxicity is very less. It can be used in multiple forms. It has the antioxidant, anti-inflammatory properties apart from antibiotic properties and potency of the material improves as it matures with time. But the constituents of Propolis differ with the different sources of procurement. We wanted to evaluate the efficacy of the Propolis procured from Hubballi against Candida albicans in this study. METHODS In this invitro study, Hubballi Propolis was extracted by maceration and refluxing. Water and 70 % ethanol were used as extraction solvents. Total Phenolic and flavonoid contents were determined by using Folin - Ciocalteu spectrophotometric method and Aluminium chloride colorimetric method respectively. Antimicrobial sensitivity effect of Propolis was estimated by determining the minimum inhibitory concentration (MIC) of the samples. RESULTS The results of the studies revealed that propolis samples have effective antifungal activity against Candida albicans with MIC range from 0.01mg / ml to 0.03 mg / ml and comparable high total phenolic (TP) and total flavonoid (TF) contents ranging from 175.4 ± 5.7 to 192.2 ± 3.3 and 33.08 ± 10 to 31.73 ± 8.5 mg / ml respectively. CONCLUSIONS Hubballi Propolis can be used for treating Candidal infection. Further, water extract Propolis showed better in total phenolic content (TPC) and total flavonoid content (TFC) than the alcohol extract. This finding is important to overcome the disadvantage of alcohol extract and hence very useful for application in Dentistry, cosmetics and pharmaceutical industry. KEY WORDS Antifungal Activity, Hubballi Propolis, Flavonoid Content, Phenolic Content

Background: Members of the genus Centaurea L. (Astraceae) are used in some countries for betterment of various ailments in the popular medicine. The main group of secondary metabolites in plants are phenolic compounds and flavonoids which are the main subset of phenolic compounds, possess a lot of biological properties such as antioxidant activity. The aim of present research is to determine in vitro total phenol and flavonoid contents, antioxidant potency and also antibacterial activity of the methanolic extracts of capitulla and aerial parts of three Centaurea species, namely C. sosnovsky Grossh., C. irritans Wagenitz and C. kandavanesis Wagenitz. In addition, any relationships between the phenolics content and their antioxidant properties were discussed. Methods: To determine total phenol and flavonoid contents of the methanolic extracts, Folin-Ciocalteu and aluminum chloride methods were used, respectively. To evaluate antioxidant activity three different test systems, namely 2, 2-diphenyl-1-picrylhydrazyl free radical scavenging (DPPH), Cu-chelating and s-carotene/linoleic acid bleaching were used. In addition, disc diffusion method was used to assess antibacterial activity of the extracts against 6 gram positive and negative bacteria. Results: Results indicated that the highest total phenol content (98.91 ± 1.87mg GAE/g of dry extract) represented by the aerial part extract of C. kandavanensis. The highest total flavonoid content (5.382 ± 0.231mg GAE/g of dry extract) and also DPPH radical scavenging activity (IC50; 0.20 ± 2.02 mg/ml) were exhibited by the capitulla extract of C. sosnovsky. However, the aerial part extract of C. irritans had the most potency for β-carotene bleaching (74.74%) among the studied samples. In addition, the extracts had acceptable antibacterial activity against both gram-positive and gram-negative bacteria tested. Conclusion: Overall, high content of phenolic compounds and proper antioxidant activity of the examined Centaurea extracts may suggest them as potent antioxidants for special use in future.

本試驗以綠豆抗豆象品系VC6089A、其近同源但不抗豆象品系VC1973A及日正綠豆 (日正食品工業股份有限公司，南北坊綠豆) 為材料，探討於黑暗中栽培高植化素含量綠豆芽之最適環境條件。綠豆種子於20˚C、26˚C與32˚C浸水0、4、8及12小時，其乾重隨浸種時間延長而降低。以四種密度栽培綠豆芽，收穫指數 (harvest index) 以7 g·cm-2種子最佳，其下胚軸較長、總類黃酮 (total flavonoids) 含量較高；密度試驗中，綠豆芽總酚類含量與收穫指數之間 (r=0.74***) 、總酚類 (total phenolics) 含量及總類黃酮含量之間 (r=0.77***) 皆呈正相關。以壓重0、100、200、300、400 g·51.84 cm-2栽培綠豆芽，VC1973A及日正綠豆於400 g·51.84 cm-2處理下，其豆芽下胚軸較粗短，根長亦較短；壓重試驗中，綠豆芽總類黃酮含量與DPPH自由基清除能力[α,α-diphenyl-β-picrylhydrazyl radical scavenging activity]間，以及總類黃酮含量與FRAP鐵離子氧化還原能力 (ferric reducing antioxidant power, FRAP ) 間之相關係數r分別為0.82***與0.64***。繼以16 h/8 h為一週期，於26˚C/20˚C、26˚C/23˚C、26˚C/26˚C、29˚C/20˚C、29˚C/23˚C及29˚C/26˚C栽培綠豆芽，VC6089A在29˚C/23˚C 及26˚C/26˚C栽培之鮮重較佳，VC1973A與日正綠豆則分別於29˚C/23˚C與26˚C/26˚C之鮮重較佳；綠豆芽之可溶性固形物及可溶性蛋白質含量顯著受栽培溫度組合之影響；而VC1973A綠豆芽之總類黃酮及總酚類含量皆較其他兩綠豆芽高。相較於0、10、20與50 mM氯化鈉溶液，以15 mM氯化鈉溶液栽培綠豆芽時，其產量較高、總類黃酮及總酚類含量最高，且VC1973A綠豆芽之亞鐵離子螯合能力(Fe2+ chelating ability)較高；氯化鈉試驗中，綠豆芽鮮重分別與可溶性糖含量 (r=0.83***) 、總類黃酮含量 (r=0.84***) 、總酚類含量 (r=0.85***) 及DPPH自由基清除能力 (r=0.85***) 皆呈高度正相關，而總酚類與總類黃酮含量或可作為DPPH自由基清除能力及FRAP鐵離子氧化還原能力之參考指標。以0、10、25、50、75及100 mM葡萄糖溶液栽培綠豆芽，50 mM組之抗壞血酸及總類黃酮含量較高，100 mM組含有較多的可溶性固形物及可溶性蛋白質。綜之，VC1973A綠豆芽之鮮重、外觀及植化素含量皆優於以VC6089A及日正綠豆栽培之綠豆芽。故建議於全黑暗環境下，以種子密度7 g·cm-2、壓重400 g·51.84 cm-2、15 mM氯化鈉溶液及29˚C 16 h /23˚C 8 h，栽培VC1973A綠豆芽3天，可獲得總類黃酮 (0.38 mg·g-1DW) 及總酚類含量 (11.1 mg·g-1DW) 、亞鐵離子螯合能力 (84.8 % of 50 mg DW·mL-1) 、DPPH自由基清除能力 (54.1 % of 50 mg DW·mL-1)與FRAP鐵離子氧化還原能力 (150.9 µmol FeSO4·g-1DW) 最高、且產量 (54.5 g FW·51.84 cm-2) 亦佳之綠豆芽。

The total phenolic and flavonoid content were assessed in Ficus deltoidea that growing in the greenhouse under four different water field capacity (FC) condition, namely: A40 (40% FC), A60 (60% FC), A80 (80% FC), and A100 (100% FC-control) and in the field, investigated for 6, 9, and 12 months after planting (MAP). This finding showed that the drought stress treatment increased the total phenolic content (TPC) and total flavonoid content (TFC) of F. deltoidea that grown in the greenhouse. The highest TPC of stems extract were obtained on A40 at 12 MAP, whereas the highest TFC of stems extracts found at 6 months MAP. Leaves extract has the higher TPC and TFC on 12 MAP as compared to 6, and 9 MAP. The result showed that the older the plant age of F. deltoidea the higher the TPC and TFC of leaves. At the 12 MAP, the leaves extract has the higher TFC as compared to the stems extract.

The influence of extraction techniques with different solvents on the contents of total phenols, flavonoids and antioxidant activity of extracts of grape, sour cherry and black currant is analyzed in the study. Antioxidant activity of the extracts on stable 1,1-diphenyl-2-picryl hidrazyl (DPPH) radical was determined by spectrophotometry. The total phenolic content was determined by using the Folin-Ciocalteu assay while total flavonoid content was measured spectrophotometrically with the application of AlCl 3 . The changes in the value of these parameters after deep-freezing of these fruits were also observed. A high content of total phenols and flavonoids was detected in extracts. Acetone proved to be the best agent for extraction of grape and sour cherry while the highest content of total phenols with black currant was obtained by methanol. The content of total phenols in fruits in frozen state increased while the content of total flavonoids and of antioxidant activity decreased. The obtained results show that the extracts of grape, cherry and black currant can be used as natural antioxidants.

The influence of extraction techniques with different solvents on the contents of total phenols, flavonoids and antioxidant activity of extracts of grape, sour cherry and black currant is analyzed in the study. Antioxidant activity of the extracts on stable 1,1-diphenyl-2-picryl hidrazyl (DPPH) radical was determined by spectrophotometry. The total phenolic content was determined by using the Folin-Ciocalteu assay while total flavonoid content was measured spectrophotometrically with the application of AlCl3. The changes in the value of these parameters after deep-freezing of these fruits were also observed. A high content of total phenols and flavonoids was detected in extracts. Acetone proved to be the best agent for extraction of grape and sour cherry while the highest content of total phenols with black currant was obtained by methanol. The content of total phenols in fruits in frozen state increased while the content of total flavonoids and of antioxidant activity decreased. The obtained results show that the extracts of grape, cherry and black currant can be used as natural antioxidants.

Aims: Plants need an appropriate amount of nutrients such as copper for growth and development. However, excess of copper may interrupt plant development and cause stress that led to biochemical compounds being synthesized. The influence of a high copper sulfate concentration on phenolic and flavonoid content in Phyllanthus tenellus plants was investigated.
 Place and Duration of Study: The experiment was conducted in a government compound at MARDI Serdang, Selangor, Malaysia (2° 59' 31.7292'' N 101° 41' 56.706'' E), from April 2021 to Jun 2021.
 Methodology: The experiment was conducted using a vertical column planting system under a side-netted rain shelter. The plants were subjected to 0.5 M copper sulfate sprayed after 60 days of planting and harvested 0.5, 1.5, 3, 6, 12 and 24 h after sprayed for further analysis. Total phenolic content was calculated as mg gallic acid equivalent and total flavonoid content was measured as quercetin equivalent.
 Results: Highest total phenolic and flavonoid content was detected after 0.5 hours of copper sulfate application and started to decrease towards 24 hours after sprayed. Treated samples showed a 1.18-fold increase in total phenolic content and 1.4-fold increase in total flavonoid content compared to control untreated samples after 0.5 hours of sprayed. Control samples showed stability in both total phenolic and flavonoid content throughout the harvesting periods. Phenolic is the major secondary metabolites in Phyllanthus tenellus plants.
 Conclusion: Data revealed that the application of 0.5 M copper sulfate is able to enhance total phenolic and flavonoid content in Phyllanthus tenellus plants. The study suggested that the optimum harvesting time is 0.5 hours after copper sulfate application.

Objective: Sterculia quadrifida R. Br. of Sterculiaceae family is locally known as “Faloak” in East Nusa Tenggara Province, Indonesia. S. quadrifida is used in folk medicine to treat hepatitis, rheumatism, and to recover stamina. The aim of this study was to determine the total flavonoids, total phenolic content (TPC), and antioxidant activity of extracts from different plant parts of S. quadrifida.
 Methods: The sampled parts of S. quadrifida were non-stripped stem bark, new regrown stem bark, old regrown stem bark, root bark, branch bark, and leaves. Stem bark was classified into three categories, namely, bark that has never been peeled (non-stripped stem bark), old regrown stem bark (estimated to be >6 months after debarking), and new regrown stem bark (estimated to be <6 months after debarking). Total flavonoid content (TFC) was determined by colorimetric aluminum chloride method and TPC was measured using Folin–Ciocalteu’s reagent. Antioxidant activity was determined with 2,2-diphenyl-1-picrylhydrazyl (DPPH).
 Results: The concentrations of flavonoids in S. quadrifida extracts from different plant parts varied from 0.58±0.13 to 1.25±0.10 mg QE/g. The TPC in the extracts of different plant parts ranged between 8.61±0.09 and 10.43±0.08 mg GAE/g. Branch bark has the highest total flavonoid and phenolic content. The extract of new regrown stem bark exhibited potent antioxidant activity with inhibitory concentration (IC50) values of 2.51±0.03 μg/ml.
 Conclusion: This study demonstrated for the first time that extracts from different plant parts of S. quadrifida exhibited strong antioxidant activity. However, the total phenolic and flavonoid contents in S. quadrifida only indicated a weak correlation with its antioxidant activity.

Total phenolic, flavonoid content, and antioxidant activity of flour, noodles, and steamed bread made from different colored wheat grains by three milling methods

In this study there were evaluated total phenolic and flavonoid contents, and ferric reducing antioxidant power (FRAP)of 3 herbs species, that are commonly used in fresh stage (summer savory –Satureja hortensisL., marjoram –Majorana hortensisM. and thyme –Thymus vulgarisL.) in dependence on time of harvest. The total flavonoid content ranged from 2.36 to 4.10 g of catechin equivalents (CE).100g−1of dry weight (dw) of plant material. The highest average total flavonoids content was ascertained in aerial part of summer savory colected in first harvest (4.10 g CE.100g−1dw) and the lowest in aerial part of summer savory collected in third harvest (2.36 g CE.100g−1dw). The highest total flavonoid content was measured by all tested species in plant material harvested in first time of harvest. The highest total phenolic content was estimated in plant material of marjoram harvested in the second time of harvest (6.74 g gallic acid equivalents (GAE).100g−1dw) and the lowest in aerial part of summer savory harvested in the third time of harvest (4.16 g GAE .100g−1dw). Ferric reducing antioxidant power (FRAP) ranged from 1,13 (summer savory, harvest No. 3) to 1.91 g GAE .100g−1dw (thyme, harvest No. 1). The best results of total flavonoid content, total phenolic content and FRAP were obtained by marjoram. Among harvest times there were the highest contents of measured compound mainly by the samples collected in the first time of harvest.