Determination Of Total Flavonoids Research Articles

Hyperspectral Imaging Combined with Deep Transfer Learning to Evaluate Flavonoids Content in Ginkgo biloba Leaves.

Ginkgo biloba is a famous economic tree. Ginkgo leaves have been utilized as raw materials for medicines and health products due to their rich active ingredient composition, especially flavonoids. Since the routine measurement of total flavones is time-consuming and destructive, rapid, non-destructive detection of total flavones in ginkgo leaves is of significant importance to producers and consumers. Hyperspectral imaging technology is a rapid and non-destructive technique for determining the total flavonoid content. In this study, we discuss five modeling methods, and three spectral preprocessing methods are discussed. Bayesian Ridge (BR) and multiplicative scatter correction (MCS) were selected as the best model and the best pretreatment method, respectively. The spectral prediction results based on the BR + MCS treatment were very accurate (RTest2 = 0.87; RMSETest = 1.03 mg/g), showing a high correlation with the analytical measurements. In addition, we also found that the more and deeper the leaf cracks, the higher the flavonoid content, which helps to evaluate leaf quality more quickly and easily. In short, hyperspectral imaging is an effective technique for rapid and accurate determination of total flavonoids in ginkgo leaves and has great potential for developing an online quality detection system for ginkgo leaves.

Toxicity Test, Antioxidant Activity, and Determination of Total Flavonoid Content (TFC) of N-Hexane and Ethyl Acetate Fraction from Uncaria Nervosa Elmer (Bajakah) Root Wood

Uncaria nervosa Elmer (local name: Bajakah) is one of the medicinal plants used as a cancer drug by the people of Muara Badak, East Kalimantan. The purpose of this study was to determine the total flavonoid content (TFC), toxicity, and antioxidant activity of the n-hexane (NH) and ethyl acetate (EA) fractions of Uncaria nervosa root wood. Determination of total flavonoids was carried out using a UV-Vis spectrophotometer with quercetin as a standard, toxicity test was carried out using the brine shrimp lethality test (BSLT) method, and antioxidant test using the DPPH radical reduction method. Based on the results of this study, the total flavonoid content (TFC) of NH and EA fractions were 192 and 425 mg QE/g extract, respectively. Based on the results of the toxicity test on Artemia salina L. shrimp, the LC50 values were 11.91 ppm for NH and 33.19 ppm for EA. These LC50 values indicate that NH is very toxic and EA is toxic against Artemia salina L. While the antioxidant test results showed that EA was very significant as an antioxidant and NH was moderate with IC50 values of 17.54 ppm and 75.93, respectively.

Method development and validation for the quantitative determination of total flavonoids through the complexation of iron (III) and its application in real sample

BackgroundThe determination of flavonoids in real sample using UV–Vis spectrophotometer commonly uses quercetin and catechin with Al+3 complexing agent as reference materials for the calibration of the instrument. However, getting these standard materials is challenging due to its expense and unavailability in the chemical reserve of the country. Moreover, the Al+3 - quercetin complexation standard method demands high amount of quercetin in spite of its high cost. Hence, developing alternative method that can solve this problem is crucial for the determination of flavonoids in the real sample. ResultsAn iron-based complexation method for the determination of flavonoids in the real sample was developed that reduces the amount of quercetin by 200 times (1 mg/mL to 0.005 mg/mL) during the calibration of UV–Vis spectroscopy as an alternative method. The reaction parameters (incubation time, pH, and concentration of quercetin) were optimized using software Design Expert 11 and confirmed by the practical experiments. The kinetics of reaction between iron and quercetin was found to be pseudo first order with rate constant of kobs at 340 and 510 nm. The analysis window for the flavonoid complex was achieved with the kinetic discrimination of the interferences at its optimized time of complexation 20 min and absorbance maxima of 510 nm. The developed method was validated by evaluating its precision, accuracy, recovery test (84–117%), detection limit and quantification limit following the standard protocols. The calibration of the instrument has been developed for the new method and the linear regression coefficient (R2) of 0.998 was obtained. SignificanceApplying the developed standard material (Fe3+ - quercetin complex) gives freedom for the analytical chemists to find the standard materials that is accessible and cheaper than the existing one (Al3+-quercetin complex). The developed method can also be easily applied for determination of flavonoid in the real samples without potential interferences coming from sample matrix.

Bioactive Phytochemical Contents on Fruit Peel of Several Citrus Species

Citrus fruits contain important sources of bioactive compounds, including antioxidants such as flavonoids and phenolic compounds that are beneficial for human health. These bioactive compounds also exist in non-edible fruit parts, like the peel. The research was conducted to evaluate these bioactive phytochemicals on the peels of different citrus species. The experiment was carried out from March to August 2018 at the citrus germplasm collection of the Indonesian Instrument Standard Assessment Institute for Citrus and Subtropical Fruits and The Central Laboratory of The Indonesian Instrument Standard Assessment Institute for Legumes and Tubers Crops. The steps of research methods included the preparation of extract samples, the determination of total flavonoids and phenol content, and the DPPH radical scavenging assay. The results showed that the bioactive content of the citrus peels of several citrus species was diverse among the studied citrus species. Tangerine citrus cv. Kintamani was observed to have a higher phenolic content. For flavonoid content, the peel of lime cv. Borneo had the highest and Mandarin cv. Satsuma showed the least. Higher DPPH radical-scavenging activity values were observed on Mandarin cv. Pachuan, tangerine cv. Kintamani, and pumello cv. Thn. The correlation between phenolic content and DPPH radical-scavenging activity was higher than that between phenolic-flavonoid and flavonoid-DPPH radical-scavenging activity, indicating the effect of active molecule structure on redox potential.

Phytochemical Screening Analysis and Determination of Total Flavonoids and Total Phenolics Content of Ethanol Extract of Sungkai Leaf (Penorema canescens Jack) from Samarinda City

Sungkai is a plant that contains compounds such as flavonoids, tannins, phenolics, saponins, steroids, and terpenoids, which have the potential to develop native Indonesian herbal medicines to treat the prevention and treatment of various diseases. This research aimed to analyze phytochemical screening and the total flavonoid and phenolic content in sungkai leaves originating from Samarinda City. This research method was carried out by extracting sungkai leaves with 96% ethanol and evaporating them with a vacuum rotary evaporator. Sungkai leaf extract was analyzed for phytochemical screening using the tube method with color testing from various reagents and total phenolic and flavonoid content testing using the colorimetric method using a UV-Vis spectrophotometer. The results of the phytochemical screening showed that the ethanol extract of sungkai leaves from Samarinda City was positive for containing flavonoids, saponins, alkaloids, phenolics, and steroids. The results of determining the flavonoid and phenolic content of sungkai leaf ethanol extract were 18,210 ± 0.271 mg QE/g sample and 33,666 ± 1.052 mg GAE/g sample.

Antioxidant activity and inhibition of α-glucosidase from extract and fraction of leaves and stems of Vernonia amygdalina

Previous studies have shown that bitter leaf (<em>Vernonia amygdalina</em> Del.) has the ability as an antioxidant and an α-glucosidase inhibitor. Still, the difference in antioxidant activity and α-glucosidase inhibition based on the leaves and stems parts have not yet been determined. The effect of flavonoid-enriched extract on antioxidant activity and inhibition of α-glucosidase has not yet been determined. This research aimed to assess the impact of flavonoid-enriched extract from the leaves and stems part of the bitter leaf. The leaves and stems part of the bitter leaf were extracted using Soxhlet apparatus with 80% methanol and then underwent successive fractionation with petroleum ether, chloroform, and ethyl acetate. The crude extract and the fraction were concentrated and followed by the determination of total flavonoid, total phenolic, antioxidant activity, α-glucosidase inhibition activity, and calculated the IC<sub>50</sub> of α-glucosidase inhibition. This research showed that chloroform-ethyl acetate leaf fraction was the best fraction with the higher total flavonoid (24.091±0.972 mg QE/g DW), total phenolic (84.299±4.589 mg GAE/g DW), diphenylpicrylhydrazyl (DPPH) antioxidant activity (33.881 μM TE/g DW), ferric reducing antioxidant power (FRAP) antioxidant activity (312.022±1.745 μM TE/g DW) and α-glucosidase inhibition activity with an IC<sub>50</sub> value 1.23 mg/mL.

FIA Online Spectrophotometric Determination of Total Flavonoids in Plants and Its Application for Batch Adsorption Kinetics

FIA Online Spectrophotometric Determination of Total Flavonoids in Plants and Its Application for Batch Adsorption Kinetics

Determination of total flavonoids, phenolics, and antioxidant activity of propolis from six stingless bee species in Kenya

AbstractBackgroundPropolis is one of the hive products made by bees from wax and plant resins, which makes it rich in phytochemicals such as flavonoids and phenolic. The chemical composition of propolis from stingless bees is affected by several factors including vegetation type and species. In Kenya, we have diverse landscape vegetation and over 12 stingless bee species. Lifestyle diseases are affecting more people due to unhealthy diets and exposure to harmful chemicals, which lead to oxidation in cells. This led to the production of super radicals, which cannot be neutralized only by the endogenous antioxidants in the body. This has led to increased demand for exogenous antioxidants obtained from the diet. Propolis is a known source of natural antioxidants too due to the presence of polyphenols.ResultsIn our study, we determined the total content of flavonoids, phenolic, and the antioxidant activity of propolis from six stingless bee species from Kenya. The total flavonoid content (TFC) in all species ranged from 651.90 to 3262.26 mg QE/100 g, while the total phenolic content (TPC) ranged from 586.36 to 2010.53 mg GAE/100 g. Among the species, Meliponula beccarii had the highest concentration of total flavonoids, Meliponula togoensis had high concentrations of total phenolic, while Meliponula ferruginea had the highest antioxidant activity.ConclusionThe outcome of this study demonstrates that propolis from Kenyan stingless bees have varying amounts of phytochemicals, which is dependent on the species identity. Hence it is a good source of exogenous natural antioxidants.

Quantitative determination of total flavonoids in Glycyrrhiza Glabra L. herbs

Licorice herb (Glycyrrhiza glabra L.) is a promising herbal raw material, which can be comprehensively used to develop drugs with an anti-inflammatory action.The aim of the article was to development a quantitative determination method of total flavonoids in Glycyrrhiza glabra L. herbs.Materials and methods. The subjects of research were 5 samples of licorice herb harvested in summer in various places of growing and cultivation. Pinostrobin was used as a standard sample. The registration of the electronic spectra was carried out with a spectrophotometer (Analytik Jena AG, Germany) by differential spectrophotometry, 96% ethanol was used as a solvent.Results. The methods for quantitative determination of total flavonoids in Glycyrrhiza glabra L. was carried out at an analytical wavelength of 310 nm equivalent to pinocembrin. The optimum parameters for the extraction of total flavonoids from Glycyrrhiza glabra L. were as follows: the extractant – 90% ethanol; the «raw material-extractant» ratio was 1:50; the extraction time was 60 min; the degree of atomization was 2 mm. The content of total flavonoids for the Glyccyrhiza glabra L. herb has been determined, it varies from 0.39±0.002 to 3.41±0.015% with the humidity of the vegetative raw material from 9.97±0.003 to 10.03±0.003% depending on the place of the vegetation, cultivation and year of the raw material collection. The error of the single determination with a 95% confidence level was ±0.73%.Conclusion. The developed methods for the quantitative determination of total flavonoids in Glycyrrhiza glabra L. herbs can be used to solve the issues of standardization of these medicinal plant raw materials.

Optimization of extraction condition of Gynura procumbens extract enriched with flavonoid and antioxidant compounds using Response Surface Methodology

Gynura procumbens is known as one of the herbal medicinal plants found in Indonesia and has been used from time to time. It is claimed to have various efficacy such as anti-hyperglycemic, anti-hypertension, anti-microbial, anti-cancer, and antioxidant. Other studies mention that G. procumbens possessed high antioxidant compounds and had been used as a natural-based medicinal supplement. However, further studies on optimizing the extraction process of Gynura procumbens in Indonesia have yet to be reported. Therefore, this study aimed to optimize the extraction condition of G. procumbens leaves by maceration with three variables: solvent concentration, extraction time, and the ratio of solid-liquid used. Each of those variables contained three different levels. Determination of total flavonoid and antioxidant activity was measured using aluminium chloride colourimetric assay and 2, 2-diphenyl-1-picryl-hydrazil (DPPH) assay, respectively. In the optimization process, Response Surface Methodology (RSM) was used to explore the main effects and interaction between parameters and their correlations with dependent variables. The results were analyzed using the Box-Behnken method using Minitab software 17. This study shows that the most significant effect of the variable for both flavonoid and antioxidant activity was solvent concentration, with a P<0.05. The results showed that the extraction process to obtain G. procumbens extract with optimal flavonoid content and antioxidant activity (IC50) was predicted at 70% solvent concentration, 1 h maceration time, and a solid-liquid ratio of 1:9.8 w/v, with results of 17.599 mg QE/g extract and 0.211 mg/mL, respectively. This study was expected to complement other studies and can be used as an additional reference for the development of the extraction process on a larger scale.

Profiling of Active Compounds of Extract Ethanol, n-Hexane, Ethyl Acetate and Fraction Ethanol of Star Anise (Illicium verum Hook. f.) and Determination of Total Flavonoids, Total Phenolics and Their Potential as Antioxidants

Profiling of chemical compounds on star anise extract and fractions showed the content and looked for active compounds. The main compounds in alkaloids, flavonoids, saponins, phenolics, and triterpenoid forms were identified based on phytochemical screening. FTIR and GC-MS analysis were used to purify the extract and fractions’ main compounds. After analyzing the main components of extract and fractions, a correlation was made between the total phenolic and flavonoid content. The total phenolic content was determined by adding folincalteau complexing solution converted to gallic acid equivalent (GAE), while the total flavonoid content was determined by AlCl3 complexing solution converted to Quercetin Equivalent (QE). The total phenolic yields for extract ethanol, n-hexane fraction, ethyl acetate fraction, and fraction ethanol were obtained at 106.45, 52.30, 93.46, and 148.97 mgGAE/g, respectively. Then the total flavonoid results were 107.45, 58.94, 148.99, 140.01 mgQE/g. The total content of phenolics and flavonoids illustrated the number of active compounds that have a role as free radical scavengers due to their group. Antioxidant activity was tested with 1,1-diphenyl-2-picrylhydrazyl (DPPH) on extracts and fractions, with the best IC50 results obtained in the ethanol fraction 0.416 mg/mL.

Antioxidant activity of various solvent extracts from endophytic bacteria isolated from girang (Leea indica) leaves

Abstract. Arivo D, Mubarik NR, Rusmana I, Batubara I. 2023. Antioxidant activity of various solvent extracts from endophytic bacteria isolated from girang (Leea indica) leaves. Biodiversitas 24: 415-422. Girang (Leea indica) is one of the medicinal plants with various bioactive compounds that act as an antioxidant. However, isolating these bioactive compounds need a significant amount of biomass. Endophytic bacteria can be a good solution to produce the same bioactive compounds as their host. This study determined whether the potential isolate produces high antioxidant activity in various solvents, phytochemical screening, determination of total flavonoid and phenolic contents, and identification of the isolate. The BT4 isolate was isolated from L. indica leaves. The supernatant of BT4 was extracted in fractionated extraction. The antioxidant activity was determined using a DPPH assay. Folin-Ciocalteu and aluminum chloride colorimetric methods analyzed the total flavonoid and phenolic content. The isolate was identified using the 16S rRNA method. The best IC50 was obtained from n-butanol extract with a value of 59.021±0.541 ?g/mL. The flavonoid and phenolic contents from n-butanol extract have the value of 4.686±0.476 mgQE/g extract and 31.406±0.716 mgGAE/g extract, respectively. The BT4 isolate contained flavonoids, saponin, tannins, terpenoids, and steroids and was identical to Bacillus tequilensis with 99% similarity. This study revealed that endophytic bacteria from L. indica leaves could be a potential source of the novel natural antioxidant compound.

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.

Development of a Method of Quantitative Determination of Total Flavonoids in the Leaves of Myrtus communis

Development of a Method of Quantitative Determination of Total Flavonoids in the Leaves of Myrtus communis

Total flavonoid content and analgesic activity of ethyl acetate fraction of Indian jujube (Ziziphus mauritiana lamk) leaves

Indian jujube leaves (Ziziphus mauritiana Lamk) have various potential biological activity. Previous studies have proven that ethanol extracted from Indian jujube (Z. mauritiana Lamk) leaves had analgesic activity. This study aimed to determine the total flavonoid content and analgesic activity of the ethyl acetate fraction of Indian jujube (Z. mauritiana Lamk) leaves ethanol extract. Tested fraction was prepared by maceration using ethanol as solvent followed by fractionation using ethyl acetate. Identification of active compounds was performed using color reaction, and determination of total flavonoids by colorimetric method. Ethyl acetate fraction was further tested for its analgesic activity using the writhing method. Swiss-Webster white male mice were divided into 5 treatment groups consisting of negative control contained sodium-CMC, positive control contained sodium diclofenac, while groups 3-5 were given ethyl acetate fraction of Indian jujube (Z. mauritiana Lamk) leaves with doses of 50, 150, and 200 mg/kg BW. All interventions were administered as a single oral dose. 0.7% (w/v) acetic acid was used as a pain inducer. Analgesic activity was measured by calculating the percentage of writhing protection as a measure of the analgesic effect produced by each intervention. The data were analyzed using one-way Anova to compare analgesic activity between treatment groups. Results showed that ethyl acetate fraction of Indian jujube (Z. mauritiana Lamk) leaves at doses of 50, 150, and 200 mg/kg BW gave an effect that was not significantly different from sodium diclofenac as positive control. The ethyl acetate fraction of Indian jujube (Z. mauritiana Lamk) leaves ethanol extract contained flavonoids, saponin, and tannins with total flavonoid content of 22.41 ± 1.16% w/w. It can be concluded that the ethyl acetate fraction of Indian jujube (Z. mauritiana Lamk) leaves have analgesic activity in mice.

Rapid prediction of flavonoid content in Epimedium sagittatum by infrared spectroscopy

Epimedii Folium is a well-known Chinese herbal medicine with the effect of nourishing kidney and strengthening Yang. Its main active ingredients are flavonoids. In this study, 60 samples of Epimedium sagittatum were collected for the determination of total flavonoids(TF) including the total amount of epimedin A, epimedin B, epimedin C, and icariin(abbreviated as ABCI) specified in the Chinese Pharmacopoeia as well as rhamnosylicariside Ⅱ and icariside Ⅱ. The calibration parameters of "first derivativemultiva-riate scattering correction in 1 900-650 cm~(-1) band(4-point smoothing)" and "first derivativestandard normal variable correction in 4 000-650 cm~(-1) full band(4-point smoothing)" were confirmed respectively. The quantitative model was established via Fourier infrared spectroscopy plus attenuated total reflection(FTIR-ATR) accessory combined with partial least squares(PLS) method and then used to predict the flavonoid content of 11 validation sets. The average prediction accuracy for ABCI in calibration set and validation set was 98.985% and 96.087%, respectively. The average prediction accuracy for TF in calibration set and validation set was 98.998% and 94.771%, respectively. These results indicated that FTIR-ATR combined with PLS model could be used for rapid prediction of flavonoid content in E. sagittatum, with the prediction accuracy above 94.7%. The establishment of this method provides a new solution for the detection of a large number of E. sagittatum samples.

Chromatographic analysis (LC-MS and GC-MS), antioxidant activity, antibacterial activity, total phenol, and total flavonoid determination of Cleome arabica L. growing in Jordan

ABSTRACT The pivotal Cleome arabica L. species belongs to the Cleome genus with fascinating secondary metabolites consisting of main classes of phenols, flavonoids, and glucosinolate derivatives. The current study was carried out on three crude extracts of Cleome arabica L. plant of Jordanian origin. In terms of the valuable resources for natural new drug development. The phytochemical contents, antioxidants, and antibacterial activities, in addition to the oil composition of this species were identified. Forty-six compounds representing 96.98% of the total composition were detected from the essential oil obtained by hydrodistillation (0.06%). The oil composition was dominated by nitrogen-sulfur-containing compounds (35.66%), esters (19.64%), and oxygenated sesquiterpenes (11.92%). Butanol extract had significantly the best scavenging activities of DPPH (P < .0001), ABTS (P < .0001), and hydroxyl radicals (P < .0001) while the Aq.MeOH extract exhibits the highest flavonoid content (173.5 ± 0.002 mg Quercetin/g dry extract) and had significantly the most ferrous chelating effect (P = .0011). Also, most of the tested extracts showed antibacterial activities against bacterial strains. Our findings exhibited that the Cleome arabica L. plant from Jordan origin might be a good candidate as potential biologically compounds that could be used as a source of natural antioxidants and antibacterial agents.

DETERMINATION OF TOTAL FLAVONOID IN JAMU “X” WITH UV-VISIBLE SPECTROPHOTOMETRIC METHODS

Jamu is still the choice of Indonesian people as an alternative to modern medicine until now. As a cultural heritage of the Indonesian, jamu is still very popular from the west to the east of Indonesia. The enthusiasm of the Indonesian in consuming jamu has encouraged many traditional medicine industries to produce jamu with many kinds of claim. Jamu "X" is claimed to help maintain body health. This research was conducted to determine the total flavonoid content in jamu "X" calculated as rutin by UV-spectrophotometric method with aluminum chloride (AlCl3) reagent. Jamu "X" is a product with new formula that is expected to be marketed soon. The determination of the maximum absorbance wavelength of rutin was carried out at a wavelength of 400-800 nm and the resulting maximum absorbance wavelength of rutin was 416.5 nm. The determination of total flavonoid calculated as rutin determined using a linear regression equation from the rutin standard. The linear regression equation was determined from a rutin standard curve series with 10; 12.5; 15; 17.5 and 20 g/ml, respectively and the linear regression equation obtained y = 0.0275x + 0.093. The results of the determination of rutin in the jamu "X" were 1.474%; 1.474% and 1.469% with an average value of 1.472%.

Determination of total flavonoid and polysaccharide content in Anoectochilus formosanus in response to different light qualities using hyperspectral imaging

This study demonstrated the capability of Vis/NIR hyperspectral imaging (400–1000 nm) in determining total flavonoid (TF) and total polysaccharide (TP) content in Anoectochilus formosanus that were cultivated in different light quality environments. We extracted spectra from the whole leaf (the control) and four zones (leaf tip, margin, middle and base) respectively. Partial least squares regression (PLSR) and support vector machine regression (SVMR) were used for building prediction models using the full spectral range. PLSR models outperformed SVMR models with determination of the coefficients of calibration (R2c) and validation (R2v) being over 0.9982 and the residual predictive deviations (RPD) being over 23.21. Comparing to the model for the control, the models for the four zones achieved similar performance; the model for the middle zone achieved slightly better performance than models for the other three zones (R2v = 0.9974, RMSEV = 0.14, RPD = 18.04 for TF; and R2v = 0.9982, RMSEV = 0.20, RPD = 23.56 for TP). We further selected effective wavelengths through the correlation coefficients between single wavelength, dual-wavelength combinations and measured content of TF and TP to simplify prediction models. New PLSR models were built based on the effective wavelengths with R2v, RMSEV and RPD of 0.8990, 0.85 and 3.07 for TF, and 0.8842, 1.71 and 2.79 for TP. Obtained results showed that hyperspectral imaging is promising for rapid and accurate determination of TF content and TP content in A. formosanus based on the PLSR models and the identified effective wavelengths.

Effect of Different Organic and Chemical Compounds on Population Density of Trialeurodes vaporariorum Westwood and Some Secondary Metabolites of Bean Plant

Introduction: Greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is a serious pest of a wide range of plants, such as common bean, cucumber, tomato, pepper, lettuce, etc, in both field and greenhouse production. It typically feeds on the underside of leaves, sucking phloem sap from the plant, which causes both direct damage, by overall weakening the plant and reducing yield, and indirect damage, by excreting honeydew, on which sooty mold grows, as well as transmission of several plant viruses. The widespread use of insecticides to control T. vaporariorum has resulted in developing resistance to the insecticides and affected human’s health and safety. The utilization of plant extract and elicitors is an environmentally safe method that is used in the control recently. Therefore, alternative control strategies are required to minimize the harmful effects of insecticides. In order to control this pest, environmentally friendly methods, especially of plant origin are recently considered by researchers. For this regard, the effect of some organic compounds including methanolic and n-hexanic extract of walnut’s husk or dill’s seeds and salicylic acid, individually and in combination with spirotetramat on population density of greenhouse whitefly’s nymphs and some secondary compounds of bean plant were investigated.Materials and methods: Seeds of common bean, Phaseulus vulgaris L. (Berloty cultivar) were sown and grown in 15-cm-plastic pots in a greenhouse at 25 ± 3°C, 50 ± 10% RH, and a natural photoperiod. For the experiments, potted bean plants at 6-8 leaf stage, highly infested with T. vaporariorum nymphs, were sprayed with 12 different treatments, including: (1) spirotetramat (SP), (2) methanolic extract of walnut husk (MW), (3) n-hexanic extract of walnut husk (NW), (4) methanolic extract of dill seed (MD), (5) n-hexanic extract of dill seed (ND, (6) salicylic acid (SA), (7) spirotetramat in combination with salicylic acid (SP+SA), (8) spirotetramat in combination with methanolic extract of dill seed (SP+MD), (9) spirotetramat in combination with methanolic extract of walnut husk (SP+MW), (10) spirotetramat in combination with n-hexanic extract of dill seed (SP+ND), (11) spirotetramat in combination with n-hexanic extract of walnut husk (SP+NW), and (12) water as a control (CO). After five days, the population density of T. vaporariorum nymphs on bean plants leaves was recorded. Furthermore, the effects of tested treatments on the total phenol and flavonoid contents of bean plants were evaluated. For this reason, dried leaves (5 g) from each treatment were used for the preparation of extracts. The total phenolics of the extracts were determined using the Folin - Ciocalteu reagent. Sample and standard readings were made using a spectrophotometer (Lambda 45-UV/Visible) at 765 nm against the reagent blank. Furthermore, the aluminum chloride colorimetric method was used for determination of the total flavonoid content of treatments. For total flavonoid determination, quercetin was used to make the standard calibration curve. The absorbance was read using a spectrophotometer (Lambda 45-UV/Visible) in the wavelengths of 415 nm. Data were analyzed by one-way ANOVA using SPSS 23.0 software. Comparison of means for nymph density using SNK (Student-Newman-Keuls) multi-range test and comparison of means for secondary chemical compositions using Tukey's test at probability level five Percentage occurred.Results and Discussion: Results showed that the population density of greenhouse whitefly and the secondary metabolites of plant were significantly affected by the tested treatments. The lowest number of whitefly’s nymphs was on spirotetramat and spirotetramat in combination with methanolic extract of dill seed and the highest number was on control. Total phenolic contents ranged from 58.96 to 114.07 mg g-1 dry weight on different treatments, which the highest and lowest amount of it was obtained in spirotetramat in combination with methanolic extract of dill seed and spirotetramat in combination with n-hexanic extract of walnut husk, respectively. The highest amount of total flavonoid content of bean plants was in spirotetramat in combination with salicylic acid. The results of the present study showed that the density of greenhouse whitefly population in spirotetramate treatment was lower than other treatments but there was no significant difference with the combined treatments and methanolic extract of walnut husk. Also, all the treatments compared to the control significantly changed the population density of this pest and increased the amount of total phenolic compound in bean plant. Therefore, these compounds, especially the methanolic extract of walnut husk, can be used in integrated management programs of this pest.Conclusion: This research could provide valuable information for control of T. vaporariorum in other plants like ornamental plants in the field and greenhouse and thus can be useful for the production of healthy and organic crops. So it can be used in the IPM programs of this pest.Keywords: Salicylic acid, Plant extract, Total flavonoid, Total phenol, Whitefly