A comprehensive study of eriocitrin metabolism in vivo and in vitro based on an efficient UHPLC-Q-TOF-MS/MS strategy

The investigation on an ethnic medicinal plant of Elsholtiza bodinieri Vaniot: Chemical constituents, acute, 28-day subacute and 90-day subchronic toxicity evaluation

ETHNOPHARMACOLOGICAL SIGNIFICANCE

Elsholtiza bodinieri Vaniot, belonging to the family Lamiaceae, has important medicinal value in Yunnan province of China. Traditionally, its aerial parts have been used as an ethnomedicine to treat diaphoresis, headache, fever, cough, pharyngitis, dyspepsia, and hepatitis. However, the safety assessment of E. bodinieri is still unexplored.

AIM OF THE STUDY

This study aimed to investigate the phytochemical constituents of the hot water extract from E. bodinieri (HEEB) and evaluate the 14-day acute, 28-day subacute and 90-day subchronic toxicity by oral administration in Sprague-Dawley (SD) rats.

MATERIALS AND METHODS

The chemical constituents of HEEB were analyzed by UHPLC-ESI-HRMS/MS. Firstly, SD rats were chosen for a single oral administration of the maximum dose of 5000 mg/kg to evaluate toxicity. Subsequently, consecutive 28-day subacute and 90-day subchronic toxicity assessments of HEEB were conducted on Sprague-Dawley (SD) rats through repeated doses of 2500, 1250, 625, and 312.5 mg/kg for the former, and 1500, 1000, and 500 mg/kg for the latter. For toxicity evaluation, hematology and serum biochemical indicators were determined, and major organs of the rats were collected to calculate organ coefficients. Additionally, hematoxylin-eosin (H&E) staining was performed on the collected tissues to assess histopathological changes induced by repeated oral administration of HEEB.

RESULTS

A total of 23 compounds were identified by UHPLC-ESI-HRMS/MS analysis. Acute toxicity assessment revealed that oral administration of HEEB did not induce mortality and unnormal behavior changes in female rats over a 14-day period, suggesting that the approximate lethal dose (ALD) was higher than 5000 mg/kg. In consecutive 28-day and 90-day toxicity evaluations, HEEB doses of 2500 mg/kg and 1500 mg/kg resulted in hepatic and kidney tissue damage in both female and male rats, which was verified by the increased levels of AST, ALT, BUN, Na+, and Cl-.

CONCLUSIONS

After the acute, 28-day subacute and 90-day subchronic toxicity evaluation, the No Observed Adverse Effect Level (NOAEL) was determined as 1000 mg/kg/day. These findings not only provided a safety information for its medicinal and edible application, but also promoted the further comprehensive development of this plant.

Mint-Scented Species in Lamiaceae: An Abundant and Varied Reservoir of Phenolic and Volatile Compounds

This investigation aimed to identify the most favorable cultivar based on plant metabolites for potential targeted cultivation in the pharmaceutical industry. The analysis revealed the presence of 19 individual phenolics and 80 individual volatiles across the cultivars, a breadth of data not previously explored to such an extent. Flavones emerged as the predominant phenolic group in all mint-scented cultivars, except for peppermint, where hydroxycinnamic acids dominated. Peppermint exhibited high concentrations of phenolic acids, particularly caffeic acid derivatives and rosmarinic acid, which are known for their anti-inflammatory and antioxidant properties. Luteolin-rich concentrations were found in several mint varieties, known for their antioxidative, antitumor, and cardio-protective properties. Swiss mint and spearmint stood out with elevated levels of flavanones, particularly eriocitrin, akin to citrus fruits. Monoterpene volatiles, including menthol, camphor, limonene, and carvone, were identified across all cultivars, with Swiss mint and spearmint exhibiting the highest amounts. The study underscores the potential for targeted cultivation to enhance volatile yields and reduce agricultural land use. Notably, chocolate mint demonstrated promise for volatile content, while apple mint excelled in phenolics, suggesting their potential for broader agricultural, pharmaceutical, and food industry production.

Chemical profile, in vitro pharmacological activity and Satureja cuneifolia Ten. evaluation of essential oil based on distillation time

The medicinal plant Satureja cuneifolia Ten. was widely utilized as spice, tea and traditional medicine. The objective of the current study was to examine the chemical composition and in vitro biological activities (LOX, MMP-1, and MMP-12 enzyme inhibition activity and cytotoxicity on A549 cell line) of Satureja cuneifolia extracts and essential oils. The essential oils of the flowering aerial parts were hydro-distilled at four different distillation times (5, 30, 60, and 180 min) using the Clevenger apparatus. The total essential oil and four fragments were compared in terms of the major component, yield, and distillation time. Volatile compounds of the infusion were extracted by using HS-SPME. Ethanolic extract had the strongest inhibition activity on the LOX enzyme (84.50%), while the essential oils exhibited more cytotoxic activity on the A549 cell line than the extracts. The oils and the infusion were analyzed using GC-MS and the primary chemicals identified by LC-MS/MS.

Eriocitrin attenuates sepsis-induced acute lung injury in mice by regulating MKP1/MAPK pathway mediated-glycolysis

Metabolic reprogramming has been shown to aggravate sepsis-induced acute lung injury. In particular, enhanced glycolysis is closely associated with inflammation and oxidative stress. Eriocitrin (ERI) is a natural flavonoid found in citrus fruit that exhibits various pharmacological activities, with antioxidant, anti-inflammatory, anti-diabetic, and anti-tumor properties. However, the role of ERI in lung injury is not well understood. We established a septic mouse model of acute lung injury (ALI) using lipopolysaccharide (LPS) for induction. Primary peritoneal macrophages were isolated to verify the relevant molecular mechanism. Tissues were assessed for lung pathology, pro-inflammatory cytokines, markers of oxidative stress, and protein and mRNA expression levels. In vivo experiments showed that ERI effectively alleviated LPS-induced pathological injury, suppress the inflammatory response (TNF-α, IL-1β, IL-6 levels) and decreased oxidative stress (MDA, ROS) in murine lung tissue. In vitro, ERI increased the resistance of LPS-treated cells to excessive inflammation and oxidative stress by inhibiting the enhancement of glycolysis (indicated by expression levels of HIF-1α, HK2, LDHA, PFKFB3, and PKM2). Specifically, the beneficial effects of ERI following LPS-induced lung injury occurred through promoting the expression of MKP1, which mediates the inactivation of the MAPK pathway to inhibit enhanced glycolysis. These results demonstrate that ERI has a protective effect on sepsis-induced ALI by regulating MKP1/MAPK pathway mediated-glycolysis. Hence, ERI is a promising candidate against ALI via inhibiting glycolysis.

Berberine alleviates intestinal barrier dysfunction in glucolipid metabolism disorder hamsters by modulating gut microbiota and gut-microbiota-related tryptophan metabolites

BACKGROUND

Barberry plants can be considered as useful additives and functional compounds in various industries, especially in the food industry. Berberine (BBR), the most important functional compound in the barberry roots, has recently been used to treat obesity, diabetes, and atherosclerosis. Gut microbiota and the intestinal barrier play an important role in the development of glucolipid metabolism disorders (GLMDs). However, the association of gut microbiota metabolism disorder and the intestinal barrier dysfunction effect of BBR in GLMDs remains elusive.

RESULTS

The results showed that administration of BBR could increase the number of colonic glands and goblet cell mucus secretion, improve the intestinal barrier function, and reduce the serum glycolipid level in GLMD hamsters. Interestingly, BBR was metabolized into 12 metabolites by gut microbiota, and the main metabolic pathways were oxidation, demethylation, and hydrogenation. In addition, BBR significantly improved the species diversity and uniformity of gut microbiota and promoted the proliferation of beneficial microbiota. Furthermore, the levels of tryptophan metabolites, such as indole, indole-3-acetamide, indole-3-acetaldehyde, indole-3-pyruvic acid, and indole-3-acetic acid were significantly altered by BBR. Both the intestinal tight junction proteins and intestinal immune factors were altered by BBR.

CONCLUSION

BBR could alleviate intestinal barrier dysfunction of GLMDs by modulating gut microbiota and gut-microbiota-related tryptophan metabolites, which may be one of the pharmacological mechanisms for the treatment of GLMDs. © 2022 Society of Chemical Industry.

Metabolism of eriocitrin in the gut and its regulation on gut microbiota in mice

Introduction

Eriocitrin, found in lemon fruit, has shown a wide range of biological properties. Herein, we investigated the intestinal metabolic profile of eriocitrin in colon, and the regulation of dietary intervention of eriocitrin on gut microbiota.

Methods

We performed ultra performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS), 16S rDNA gene sequencing and gas chromatography-mass (GC-MS) on colon contents from the eriocitrin group (n=6), and compared them with control participants (n=6).

Results

A total of 136 flavonoids were found in colon contents, including eriocitrin and its six metabolites (eriodictyol, homoeriodictyol, hesperetin, eriodictyol-3'-O-glucoside, hesperetin-7-O-glucoside and eriodictyol-7-O-(6″-O-galloyl) glucoside). Moreover, dietary intervention of eriocitrin significantly alters the beta diversity of the gut microbiota, the probiotics such as Lachnospiraceae_UCG_006 were significantly enriched, and the production of butyrate, valerate and hexanoate in the colon pool of short-chain fatty acids were significant increased. The spearman's association analysis performed some intestinal bacteria may be involved in the metabolism of eriocitrin.

Discussion

Collectively, our results preliminarily suggest the metabolism of eriocitrin in the gut, demonstrating alterations of eriocitrin in gut microbiota, which warrants further investigation to determine its potential use in food and biomedical applications.

Gender differences pharmacokinetics, bioavailability, hepatic metabolism and metabolism studies of Pinnatifolone A, a sesquiterpenoid compound, in rats by LC-MS/MS and UHPLC-Q-TOF-MS/MS

BACKGROUND

Pinnatifolone A is a typical sesquiterpenoid and the primary active ingredient of Syringa oblata Lindl., has potent anti-inflammatory activity. However, Pinnatifolone A pharmacokinetic and metabolites analysis investigations in male and female rats, as well as its in vitro stability in male and female rat liver microsomes, have not been evaluated and compared.

PURPOSE

To investigate preclinical pharmacokinetic and metabolite in both genders, confirm gender differences, and provide usable information for the development of clinical applications.

METHODS

A quick, precise, and sensitive LC-MS/MS method was created and effectively used to determine the pharmacokinetics of oral (140 mg/kg) and intravenous (6.3 mg/kg) Pinnatifolone A in male and female rats, in vitro Pinnatifolone A elimination studies in male and female rat liver microsomes. Following that, a UHPLC-Q-TOF-MS/MS technique was established to identify the metabolic profiles of Pinnatifolone A obtained from rat plasma and excreta.

RESULTS

In the current study, we established for the first time an LC-MS/MS method for the quantitation of Pinnatifolone A with acceptable linearity and selectivity, recovery and matrix effect, accuracy and precision. The absolute oral bioavailability of Pinnatifolone A was approximately 30.36% in female rats, the clearance (CL) was 20.99±3.33 l/h/kg in female rats and 472.37±437.31 l/h/kg in male rats. This difference in rat genders may pertain to the sex-specific expression of hepatic enzymes as demonstrated in the metabolic stability evaluation in the present research; the male rats exhibited higher CL_int(mic) (158.83±9.57 μl/min/mg protein) than female rats (76.47±7.90 μl/min/mg protein) liver microsomes, indicating higher Pinnatifolone A clearance in male rats. Twenty-four metabolites were detected and identified in female and male rats; N-acetylcysteine conjugation metabolite was the most abundant metabolites in both rat feces and urine. Furthermore, male and female rats had significantly different levels of the N-acetylcysteine conjugation metabolite. Hydrogenation metabolite was particular to female rats both in rat fecal and urine. Glucuronide conjugation metabolite was the predominant metabolite in rat plasma, and its amount in female rats was double that of male rats.

CONCLUSIONS

The present research is the first to report the preclinical pharmacokinetics and metabolites of Pinnatifolone A in male and female rats, confirming the gender-based differences. The findings provide a comprehensive overview for further understanding of the pharmacokinetic and metabolic characteristics of Pinnatifolone A and serve as a guide for its future development and utilization.

Citrus nutraceutical eriocitrin and its metabolites are partial agonists of peroxisome proliferator-activated receptor gamma (PPARγ): a molecular docking and molecular dynamics study

Peroxisome proliferator-activated receptor gamma (PPARγ) agonists are potent insulin sensitizers in treating type 2 diabetes. Despite being very effective in the fight against diabetes-mediated complications, PPARγ agonists are accompanied by severe side effects leading to complicated health problems, making the discovery of novel safe ligands highly pertinent. A significant intense research effort is in progress to explore the PPARγ activating potential of a wide range of natural compounds. Lemon (Citrus limon) contains various bioactive flavonoids, and eriocitrin is the major flavonoid. It possesses substantial antioxidant and anticancer, lipid-lowering activities and prevents obesity-associated metabolic diseases. Eriocitrin is metabolized to eriodictyol in the intestine, and the absorbed eriodictyol undergoes conversion to numerous metabolites in vivo. It is unclear if eriocitrin or its metabolites are responsible for their beneficial effects. We have used molecular docking, ADMET properties, drug-likeness score and molecular dynamics simulation study to find if eriocitrin and its metabolites are potent binders for PPARγ. Docking studies revealed that eriocitrin binds to PPARγ with the highest binding energy, but ADMET properties and in vivo studies show that the bioavailability of eriocitrin is very poor. Molecular dynamics studies were carried out to validate the docking results, and multiple parameters like RMSD, RMSF, Radius of gyration, SASA, hydrogen bond analysis, interaction energy, principal component analysis, Gibbs free energy and MM-PBSA were calculated. Based on our studies, eriodictyol, eriodictyol 7-O-glucuronide, eriodictyol 3'-O-glucuronide, homoeriodictyol and homoeriodictyol 7-O-glucuronide which are metabolites of eriocitrin appear to be potent partial agonists of PPARγ under physiological conditions.Communicated by Ramaswamy H. Sarma.

Eriocitrin: A review of pharmacological effects

The present study aimed to recognize the recent literature to highlight the pharmacological impacts and highlight the therapeutic potential of the active molecule eriocitrin. Citrus limon are a good resource of the flavanone eriocitrin (eriodictyol 7-O-β-D-rutinoside). Eriocitrin has potent biological actions due to its strong antioxidant, antitumor, anti-allergic, antidiabetic and anti-inflammatory activities. Eriocitrin is more potent in suppressing oxidative stress in diabetes mellitus (DM) and other chronic diseases incurred by excessive oxidative stress. During metabolism, eriocitrin is metabolized by gut microbiota, and a chain of molecules such as eriodictyol, methy-eriodictyol, 3,4-dihydroxyhydrocinnamic acid (DHCA), and much more conjugated molecules. More in-depth studies are recommended to explore this drug for clinical trials.

Phytochemical analysis and preclinical toxicological, antioxidant, and anti-inflammatory evaluation of hydroethanol extract from the roots of Harpalyce brasiliana Benth (Leguminosae)

ETHNOPHARMACOLOGICAL RELEVANCE

Harpalyce brasiliana Benth (Leguminosae) is a shrub endemic to Brazil, popularly known as "snake's root." This species is used in folk medicine for the treatment of inflammation and snakebites. However, up to now there is no scientific research to justify its popular use. The study aimed to characterize the phytochemical profile of the hydroethanol extract from the roots of H. brasiliana (Hb), to evaluate its antioxidant and anti-inflammatory potential, as well as to investigate its cytotoxicity and acute toxicity.

MATERIALS AND METHODS

The extract was obtained by maceration method using a solution of ethanol:water (70: 30, v/v). The phytochemical profile was obtained by liquid chromatography coupled to mass spectrometry. The cytotoxicity of extract (31-2000 μg/mL) was evaluated in vitro, by the 3-methyl-[4-5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method using murine macrophage and fibroblast cell lines (RAW 247.6 and 3T3, respectively) and by the hemolytic assay. For the in vivo acute toxicity, the extract (2000 mg/kg) was administered and after 14 days the weight (body and organs) and hematological and biochemical parameters were analyzed. Chemical free radical scavenging effect of the extract (125-2000 μg/mL) was investigated through diphenylpicryl hydrazine reduction, total antioxidant capacity, reducing power, hydroxyl radical scavenging, and iron and copper chelating assays. In vitro anti-inflammatory effect of the extract (125, 500, and 2000 μg/mL) was demonstrated through of nitric oxide (NO) analyzed in lipopolysaccharides stimulated RAW 264.7 cells. In vivo anti-inflammatory activities were evaluated in carrageenan-induced paw edema and zymosan-air-pouch models, with gavage administration (post-treatment) of extract at 100, 200, and 400 mg/kg. For the first animal model, the anti-edematogenic activity and myeloperoxidase (MPO) levels were investigated, while in the zymosan-air-pouch model the leukocyte number, MPO, total protein and pro-inflammatory cytokine (IL-1β, IL-6, and TNF-α) levels were quantified. In addition, the oxidative parameters such as malondialdehyde (MDA) and reduced glutathione (GSH) were determined.

RESULTS

The phytochemical profile revealed the presence of 20 compounds, mainly prenylated and geranylated pterocarpans. The extract demonstrated no cytotoxicity in erythrocytes, macrophages and fibroblasts cells at the tested concentrations, as well as no sign of toxicity and mortality or significant alterations on the hematological and biochemical parameters in the acute toxicity model. The extract was also able to neutralize chemical free radicals, with copper and iron chelating effect. For the NO dosage, the extract evidenced the reduction of expression of NO after the administration of the extract (500 and 2000 μg/mL). The edematogenic model revealed a decrease in paw edema and MPO level, while the zymosan-air-pouch model evidenced a reduction of leukocyte number (especially of polymorphornuclears), MPO production, and total protein and cytokine levels, and demonstrated the antioxidant effect through a decrease in MDA and increase in GSH parameters.

CONCLUSION

This approach demonstrates for the first time that Hb is not cytotoxic, has low acute toxicity, and possesses antioxidant and anti-inflammatory properties in preclinical analyses, corroborating its popular use.

Identification of metabolites of Ginkgolide B in vivo and in vitro using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry

Ginkgolide B is a dietary diterpene with multiple pharmacological activities. However, current research on ginkgolide B is not comprehensive. The current study analyzed the metabolic profile of ginkgolide B in vivo and in vitro using ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry . To detect and identify the different metabolites in ginkgolide B, a novel data processing method was used as an assistant tool. A total of 53 different metabolites of ginkgolide B (38 phase I metabolites and 15 phase II metabolites) were detected relative to blank samples. The biotransformation route of ginkgolide B was identified as oxidation, dehydroxylation, hydrogenation, decarbonylation, demethylation, sulfate conjugation, glucose conjugation, methylation and acetylation. The current study demonstrated a method for rapidly detecting and identifying metabolites and provided useful information to further characterize the pharmacology and mechanism of ginkgolide B. A method for the analysis of other diterpene metabolic components in vivo and in vitro was also established. This article is protected by copyright. All rights reserved.

Influences of Solubility and Vehicle Carriers on Eriodictyol Pharmacokinetics in Rats

In this study, the pharmacokinetics of oral doses of eriodictyol in 1% sodium carboxymethylcellulose and in saline/PEG400/Tween80 (75/20/5, v/v/v) in rats were compared. The pharmacokinetics of eriocitrin administered as a dissolved solution in water were also characterized. Metabolites of eriodictyol and eriocitrin in whole blood consisted mainly of eriodictyol, homoeriodictyol, and hesperetin glucuronides and ring-fission metabolites. In whole blood, no free nonconjugated flavanone aglycones were detected. Significant differences were observed in the pharmacokinetics of eriodictyol administered as a suspension in 1% sodium carboxymethylcellulose versus administration as a dissolved solution in saline/PEG400/Tween80 (75/20/5, v/v/v). At a dose of 25 mg kg^-1 eriodictyol administered with 1% sodium carboxymethylcellulose, a biphasic pharmacokinetic curve was observed, while only a single concentration peak was observed following an administration of 25 mg kg^-1 eriodictyol dissolved in saline/PEG400/Tween80 (75/20/5, v/v/v). For all trials, the pharmacokinetics of eriodictyol differed from those of eriocitrin dissolved in water.

Safety and efficacy of a feed additive consisting of a flavonoid-rich dried extract of Citrus × aurantium L. fruit (bitter orange extract) for use in all animal species (FEFANA asbl)

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of a dried flavonoid-rich extract of Citrus × aurantium L. fruit (bitter orange extract), when used as a sensory additive for all animal species. The use of the additive in feed was not expected to increase the exposure to furocoumarins of those target species that are already fed citrus by-products to a relevant extent (< 5%). For dog, cat and ornamental fish, not normally exposed to citrus by-products, no conclusion could be drawn. The FEEDAP Panel concluded that the additive under assessment is safe up to the maximum proposed use level of 400 mg/kg for veal calf (milk replacer), sheep, goat, horse and salmon. For the other species, the calculated maximum safe concentration in complete feed is 102 mg/kg for chicken for fattening, 151 mg/kg for laying hen, 136 mg/kg for turkey for fattening, 182 mg/kg for piglet, 217 mg/kg for pig for fattening, 268 mg/kg for sow, 259 mg/kg for dairy cow and 161 mg/kg for rabbit. The FEEDAP Panel considered that the use in water for drinking is safe provided that the total daily intake of the additive does not exceed the daily amount that is considered safe when consumed via feed, except dog, cat and ornamental fish. No concerns for consumer safety were identified following the use of the additive up to highest safe level in feed for the target animals. The extract under assessment should be considered as irritant to skin, eyes and the respiratory tract, and as a skin sensitiser. Since the additive contains 5-methoxypsoralen, it may cause phototoxicity. The use of the extract in animal feed under the proposed conditions was not expected to pose a risk for the environment. Bitter orange extract was recognised to flavour food. Since its function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary.

New Insights into the Metabolism of the Flavanones Eriocitrin and Hesperidin: A Comparative Human Pharmacokinetic Study

The intake of hesperidin-rich sources, mostly found in orange juice, can decrease cardiometabolic risk, potentially linked to the gut microbial phase-II hesperetin derivatives. However, the low hesperidin solubility hampers its bioavailability and microbial metabolism, yielding a high inter-individual variability (high vs. low-producers) that prevents consistent health-related evidence. Contrarily, the human metabolism of (lemon) eriocitrin is hardly known. We hypothesize that the higher solubility of (lemon) eriocitrin vs. (orange) hesperidin might yield more bioavailable metabolites than hesperidin. A randomized-crossover human pharmacokinetic study (n = 16) compared the bioavailability and metabolism of flavanones from lemon and orange extracts and postprandial changes in oxidative, inflammatory, and metabolic markers after a high-fat-high-sugars meal. A total of 17 phase-II flavanone-derived metabolites were identified. No significant biomarker changes were observed. Plasma and urinary concentrations of all metabolites, including hesperetin metabolites, were higher after lemon extract intake. Total plasma metabolites showed significantly mean lower Tmax (6.0 ± 0.4 vs. 8.0 ± 0.5 h) and higher Cmax and AUC values after lemon extract intake. We provide new insights on hesperetin-eriodictyol interconversion and naringenin formation from hesperidin in humans. Our results suggest that regular consumption of a soluble and eco-friendly eriocitrin-rich lemon extract could provide a circulating concentration metabolites threshold to exert health benefits, even in the so-called low-producers.

Identification of bilobetin metabolites, in vivo and in vitro, based on an efficient ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry strategy

Bilobetin, a natural compound extracted from Ginkgo biloba, has various pharmacological activities such as antioxidation, anticancer, antibacterial, antifungal, anti-inflammatory, antiviral, and promoting osteoblast differentiation. However, few studies have been conducted and there are no reports on its metabolites owing to its low content in nature. In addition, it has been reported to have potential liver and kidney toxicity. Therefore, this study aimed to identify the metabolites of bilobetin in vitro and in vivo. Bilobetin was incubated with liver microsomes to determine metabolites in vitro, and faeces and urine were collected after oral administration to rats to determine metabolites in vivo. After the samples were processed, they were measured using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. As a result, a total of 21 and 9 metabolites were detected in vivo and in vitro, respectively. Demethylation, demethylation and loss of water, demethylation and hydrogenation, demethylation and glycine conjugation, oxidation, methylation, oxidation and methylation, and hydrogenation were the main metabolic pathways. This study is the first to identify the metabolites of bilobetin and provides a theoretical foundation for the safe use of bilobetin in clinical application and the development of new drugs.

Polyphenol analysis using high-resolution mass spectrometry allows differentiation of drought tolerant peanut genotypes

BACKGROUND

Peanut (Arachis hypogaea L.) is an important economic food crop highly appreciated worldwide. Although peanut cultivation has been expanding to dry regions, with water stress during growth stages, current genotypes are not adapted to drought. This study aimed to identify and quantify the full range of polyphenols in five peanut genotypes with different degrees of drought tolerance developed by Embrapa (Brazil) using ultra-high-definition accurate-mass liquid chromatography-electrospray ionization-LTQ-Orbitrap-mass spectrometry.

RESULTS

Fifty-eight polyphenols of the classes hydroxybenzoic acids, hydroxycinnamic acids, flavanols, flavonols and flavanones were identified and quantified using high mass accuracy data and confirmed by tandem mass spectrometric experiments. High-definition mass spectrometric analyses revealed nine phenolic compounds that have never been reported in peanuts before. Polyphenol assessment using multivariate analysis allowed identification of the level of similarities among the five peanut genotypes studied.

CONCLUSION

Higher drought-tolerant genotypes exhibited higher content of flavonoids, which suggests a relationship between these compounds and drought tolerance traits. © 2019 Society of Chemical Industry.