Correlation of Total Phenolic and Flavonoid Contents of Brazilian Honeys with Colour and Antioxidant Capacity

Six cultivars of kiwifruits grown in Korea, including Actinidia eriantha ‘Bidan’, A. arguta ‘Chiak’, A. arguta ‘Darae No. 2’, A. chinensis ‘Haegeum’, A. chinensis ‘Haehyang’, and A. arguta × A. deliciosa ‘Mansoo’, were harvested at various maturity stages to test whether kiwifruit maturity has an influence on antioxidant capacity or total phenolic and flavonoid contents. Kiwifruit extracts were isolated using absolute methanol and then 80% (v·v-1) aqueous methanol during homogenization. ‘Bidan’, collected at the second harvest stage, contained the greatest amount of total phenolics (775.3 mg gallic acid equivalents·100 g-1 fresh weight) and had the highest antioxidant capacity [816.5, 633.2, and 2,662.7 mg vitamin C equivalents·100 g-1 fresh weight for 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging, 1,1-diphenyl-2-picrylhydrazyl scavenging, and oxygen radical absorbance capacity assays, respectively] among cultivars tested, while ‘Haehyang’, collected at the first harvest, contained the greatest amount of total flavonoids (13.1 mg catechin equivalents·100 g-1 fresh weight). Kiwifruit cultivar and genotype influenced antioxidant capacity, as well as total phenolic and flavonoid contents. No trend, however, was observed in total phenolic and flavonoid contents, and in the antioxidant capacity with respect to maturity stage. Antioxidant capacity had a higher linear correlation coefficient with total phenolic contents than with total flavonoid contents. The results above suggest that kiwifruits at various maturity stages are a valuable source of phenolics and antioxidants for industrial application and consumer health benefit.

Senna didymobotrya has been used in Kenya by the Kipsigis community to control malaria as well as diarrhoea. The Pokot prepare charcoal from the stem for milk preservation. Research has not been done to investigate the effect of different extraction solvents on yield, total phenolic and flavonoid content of Senna didymobotrya plant roots. The aim of this study was to compare root extract yield of diethyl-ether, methanol, and aqueous solvents; phytochemical screening; and total phenolic and flavonoid content of Senna didymobotrya plant roots. Extraction was done by the Soxhlet method. Phytochemical screening was done using Harborne's (1973) method with a slight modification. Total flavonoid content was determined by aluminium chloride colourimetric assay at 420 nm. Total phenolic content was determined by Folin–Ciocalteu at 760 nm using UV-Vis spectrophotometry. Extraction yield of diethyl ether, methanol, and distilled water were 3.72 g (7.44%), 4.97 g (9.94%), and 9.09 g (18.18%), respectively, showing a significant difference (p < 0.05) in the yields obtained using the different solvents. Phytochemical screening was positive for phenols, tannins, saponins, gladiac glycosides, anthraquinones, alkaloids, and flavonoids. Total flavonoid content was found to be 48.3 ± 1.5 (QEmg/g) and total phenol content was calculated as 34.5 ± 0.1 (GAEmg/g). Distilled water can be utilized as the best extraction solvent. Senna has a high amount of flavonoid and phenolic content. The limitation of this research is that it only tested root extracts and not leaves, flowers, or seeds. More studies need to be done to isolate the different compounds identified.

BACKGROUND: Peronema canescens (Sungkai) leaves have been popular in Indonesia which contain various bioactive compounds with empirical therapeutic efficacy in dealing with COVID-19 and various other diseases. Total phenolic and flavonoid content and antioxidant activity using the DPPH method from P. canescens leaf extract have not been studied much. AIM: This research has several objectives. The first is to compare the results of qualitative phytochemical analysis of the ethanol extract of the leaves of P. canescens (EEPL). The second is to measure the total phenol and flavonoid content. The third is to test the FTIR and antioxidant activity of the ethanol extract of P. canescens leaves in vitro using the DPPH method. METHODS: Fresh plant material and simplicia, ethanol extract extracted by maceration method using 96% ethanol as solvent from P. canescens. The Dragendorff’s and Mayer test carried out the qualitative phytochemical analysis, FeCl3 test, Salkowski method, Liebermann–Burchard method, foam test, and NaOH reagent. The total phenolic and flavonoid levels were tested using the Folin–Ciocalteu method. In vitro antioxidant activity was carried out using the DPPH (1,1-diphenyl-2-picrylhydrazyl) method. RESULTS: The results of qualitative phytochemical screening showed that alkaloids, flavonoids, saponins, tannins, and steroids were detected in the extract of P. canescens. The spectra from the FTIR test results showed various absorbance peak values indicating the bonding of specific functional groups, namely: 418.12, 599.94, 666.67, 1036.39, 1159.52, 1224.16, 1348.95, 1454.19, 1600.87, 1732.00, 2923.13, and 3353.01 cm-1. In the test results, total phenolic content was as much as 5.64% (mgEAG/g) and total flavonoid content of 142,247 mgEQ/g in a sample of 1 mg extract, which was equivalent to 1 mg quercetin. EEPL has antioxidant activity with the DPPH IC50 method of 116.7865 ppm. CONCLUSION: The data obtained at this time can contribute to the exploitation of P. canescens leaves in the future as one of the nutraceutical products, supplements, and herbal medicines by specific industries related to improving the health status of the world community. The higher the bioactive substance in preparation, the more significant the effect of the pharmacological efficacy response. P. canescens ethanol extract has good total phenolic content, total flavonoid content, and antioxidant action.

Phenolic and flavonoid contents of mandarin (Citrus reticulata Blanco) fruit tissues and their antioxidant capacity as evaluated by DPPH and ABTS methods

Total phenolic, total flavonoid distribution and antioxidant activity in skin, pulp and fruit extracts of 12 plum cultivars were investigated. The results showed that the levels of total phenolic and flavonoid compounds changed depending on cultivars and fruit parts. The total phenolic content in skin was 4.5 times higher than that in pulp and 3.2 times higher than that in the whole fruit. The total flavonoid content in skin was 18.7 times higher than that in pulp and 9.6 times higher than that in the whole fruit. As the trend observed for antioxidant activity, a positive relationship (correlation coefficient r2 = 0.83–0.92) was presented between total phenolics and total antioxidant capacity. The results confirm that plum is a good source of natural phenolic antioxidants. Practical Applications The present study indicated that plum can contribute to the dietary intake of antioxidants, depending on cultivars and fruit parts. It is among the few studies investigating the distribution of total phenolic, total flavonoids and total antioxidant capacity in the skin, pulp and fruit of plum cultivars. It was observed that the highest values of total phenolic and flavonoid content were obtained from skin extracts. The study highlighted that phenolics and flavonoids in plums may play an important role as radical-scavenging agents that could be used for a healthy human life. This fact may open new perspectives for plum – besides its traditional uses – to be used in assuring a wholesome diet and a healthy life.

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 .

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.

This study aims to determine and compare antioxidant activity, total phenolics, flavonoids, and the relationship of phenolic and total flavonoids with the antioxidant activity of the three kratom variants. The ethanol extract of the third variant of kratom leaves was obtained by maceration. Through the antioxidant activity test using DPPH method, all three extracts showed strong antioxidant activity with IC50 values of 26.39, 30.25, and 30.59 μg/mL. The relationship of total phenolics and flavonoids with antioxidant activity was determined by the Pearson correlation test. Examination of total phenolic content using the Folin-Ciocalteu method with successive results for green, red, and white kratom are 6.11, 8.67, and 9.09 mg GAE/g extract. Examination of total flavonoid content using the colorimetric method for green, red, and white kratom were 0.86, 0.68, and 1.13 mg QE/g extract, respectively. The total phenolic content and antioxidant activity showed a correlation coefficient value of -0.32 (P0.05), and the total flavonoid content to antioxidant activity showed a correlation coefficient value of 0.81 (P0.05). Thus, all three variants of kratom have potency as natural antioxidants, but their total phenolic and flavonoid content does not influence their antioxidant activity.

Eriobotrya plants are known to have significant amounts of phenolics and flavonoids, and exhibit a strong antioxidant activity. Experiments were conducted to examine variation in the contents of total phenolics and flavonoids, and antioxidant activities in the leaves of 11 Eriobotrya species (Tibet loquat, Daduhe loquat, Hengchun loquat, Taiwan loquat, Oak leaf loquat, Bengal loquat, Fragrant loquat, Guangxi loquat, Obovate loquat, Big flower loquat, and common loquat, the last species include two materials, one is a cultivar 'Zaozhong 6', another is a wild tree). In these species, 'Zaozhong 6' loquat is a cultivar. The leaf extracts of 'Tibet', 'Obovate', 'Taiwan', 'Bengal' and 'Hengchun' loquats exhibited significantly higher contents of total flavonoids and total phenolics, compared with those of other species. Of these 11 species, the highest contents of total phenolics and total flavonoids were observed in 'Tibet' and 'Obovatae' loquats, respectively. The significantly stronger antioxidant abilities assessed by the DPPH radical scavenging activity and reducing power were obtained in the leaf extracts of 'Taiwan', 'Tibet', 'Bengal', 'Oak leaf', 'Hengchun' and 'Obovate' loquats, compared with the other species. In addition, significant correlations were found between the contents of total phenolics or flavonoids and DPPH radical scavenging activity/reducing power. This work indicates that the leaf extracts of the wild Eriobotrya species, 'Tibet', 'Obovatae', 'Taiwan', 'Bengal', 'Oak leaf' and 'Hengchun' loquats, exhibited significantly higher levels of total phenolics and flavonoids, and significantly stronger antioxidant activities, compared with the cultivated species, 'Zaozhong 6' loquat, which suggests that these wild species have a better utilization value.

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

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.

Plants have been used since ancient times as an important source of biologically active substances. Specific activities of these plant extracts are generally linked to the presence of secondary metabolites together with their phenolic contents. Present study aimed at investigating the total phenolic and flavonoid contents, and antioxidant activity of selected plants from five different families. The total phenolic content was measured using Folin-Ciocalteu assay and total flavonoid content by aluminum chloride colorimetric method. The antioxidant capacity was estimated by phosphomolybdinium assay. Our findings indicates that total phenolic content for methanolic extracts ranged from 27.07 to 59.11 mg GAE/g DW, and total flavonoid content ranged from 38.37 to 124.23 mg QE/g DW, with an antioxidant activity ranging from 55.82 to 129.06 mg AAE/g DE. Following trend was shown in the assessment of total phenolic and flavonoid contents: Rhazya stricta>Cicer arietinum>Solanum melongena>Solanum surattense>Solanum nigrum>Withania sominifera>Sisymbrium irio>Withania coagulans>Raphanus sativus>Fagonia indica>Brassica napus. While the antioxidant capacity followed the trend: Cicer arietinum>Solanum nigrum>Withania coagulans>Rhazya stricta>Raphanus sativus>Solanum melongena>Withania sominifera>Solanum surratense>Fagonia indica>Brassica napus>Sisymbrium irio. It is also seen that both wild and cultivated plants have higher medicinal value, which can be linked to the phenolic and flavonoid content, and antioxidant potential. Findings of the study revealed that wild plants possess higher phenolic content compared to cultivated plants, whereas cultivated plants had higher antioxidant activity.

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.

Quercetin was isolated from ethyl acetate fraction of a methanol extract of the outer scale of onion by repeated sephadex LH-20 column chromatography. Methanol, 50% aqueous methanol and 70% aqueous acetone extracts of different parts of four medicinal plants, Ficus benghalensis, Elaeocarpus sphaericus, Ipomea carnea and Azeratum conyzoides were prepared and screened for total phenolic and flavonoid contents and free radical scavenging activity. The total phenolics contents were measured spectrophotometrically by using Folin-Ciocalteu reagent and total flavonoids content by using aluminum chloride colorimetric method. Free radical scavenging activity was evaluated using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay. All the investigated medicinal plant extracts contained high amount of phenolics. The highest amount was detected in 70% aqueous acetone extract of E. sphaericus (298.8±9.03 mg GAE/g extract) and lowest amount in 50% aqueous methanol extract of F. benghalensis (6.7±0.73 mg GAE/g extract). The highest amount of flavonoid was found in methanol extract (78.2±2.72 mg quercetin/g extract) and the lowest amount was detected in 50% aqueous methanol extract (2.1±0.25 mg quercetin/g extract) of F. benghalensis. DPPH free radical scavenging assay was carried out only in 70% acetone extracts. The highest IC50 value was observed for E. sphaericus (34.0 μg/ml). A strong linear correlation between total phenolic content and antioxidant activity was found indicating that the major antioxidants are phenolics.DOI: http://dx.doi.org/10.3126/njst.v15i1.12010 Nepal Journal of Science and Technology Vol. 15, No.1 (2014) 53-60

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。