Rapid determination of chlorogenic acid and related compounds in sunflower seeds by high-performance liquid chromatography/atmospheric pressure chemical ionization mass spectrometry

Metabolomic analysis and ecofriendly enrichment of sunflower meal extract

BACKGROUND

The presence of phenolic compounds in sunflower is well reported in the literature; however, knowledge is scarce when it comes to the composition of other secondary metabolites in this species and their by-products. This work evaluated, for the first time, the phytochemical composition of sunflower meal produced in Brazil. A combination of mixture design and central composite rotatable design 2³ models was then applied to maximize the recovery of bioactive compounds using ecologically friendly solvents and concentrating by applying activated carbon, a sustainable adsorbent. The product of this extraction-concentration was also evaluated by an untargeted metabolomic approach using ultra-performance liquid chromatography coupled to mass spectrometry.

RESULTS

A diverse and abundant profile of phenolic compounds was obtained from Brazilian sunflower meal: in total, 51 natural products were tentatively identified, 35 of which for the first time in sunflower. The sorption capacity of the activated charcoal, in the optimized process conditions, was effective in the separation and concentration of minority secondary metabolites. The ecofriendly extract proved to be enriched in plumberoside, p-coumaric acid, and alkaloids.

CONCLUSIONS

Investigation of the phytochemical profile of sunflower meal produced in Brazil pointed to several secondary metabolites reported for the first time in sunflower samples, including phenolic compounds, alkaloids, and terpenes. The use of activated charcoal in an alkaline medium as an adsorbent for the concentration of these phytochemicals, from an aqueous extract, generated a potentially cost-effective, ecofriendly extract, enriched in minor metabolites, indicating a possible innovative way to selectively obtain these compounds from sunflower meal. © 2022 Society of Chemical Industry.

Nitrogen deficiency maintains the yield and improves the antioxidant activity of Coreopsis tinctoria Nutt

Nitrogen (N) deficiency levels were investigated for their potential to maintain the yield and improve antioxidant activity of Coreopsis tinctoria. Inflorescences and leaves at 0, 10, 20, 30, 40, and 50 d after flowering were frozen at -80 °C and plant growth, antioxidant activity, bioactive substance, enzyme activity, and gene expression were evaluated. N deficiency maintained the total number of flowers, promoted phenol and flavonoid accumulation, and enhanced antioxidant activity. Moreover, N deficiency stimulated activities of phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H) and 4-coumarate:coenzyme A ligase (4CL), and induced CtPAL, CtC4H and Ct4CL gene expression. The data also suggest that N-deficiency-induced phenolic and flavonoid accumulation occurs due to the activation of biosynthetic pathways in C. tinctoria. We characterize the unique features of C. tinctoria under N-deficiency conditions and provide valuable information for the cultivation of high-N use efficiency varieties with low input and high output.

Natural antioxidants of plant origin

Interest in the content of natural antioxidants in plant-based foods can be from the human health perspective, in terms of how these compounds might help promote one's health and wellness, or from the storage point-of-view, as the endogenous antioxidant constituents aid to extend a foodstuff's shelf-life. This chapter reports essential information about the mechanism of antioxidant action and methods employed for determination of their activity, classes of phenolic compounds (phenolic acids, flavonoids, lignans, stilbenes, tannins), sources of plant antioxidants (oil seeds, cereals, legumes, plants of the Lamiaceae family, tea and coffee, tree nuts, fruits, and berries), extraction strategies of phenolic compounds from plant material, and the influence of processing and storage on the content of natural antioxidants in foods and their antioxidant activity. Thermal processing, if not releasing bound phenolics from the structural matrices of the food, tends to decrease the antioxidant potential or, in the best case scenario, has no significant negative impact. Gentler sterilization processes such as high-pressure processing tend to better retain the antioxidant potential of a foodstuff than thermal treatments such as steaming, boiling, or frying. The impact of processing can be assessed by determining the antioxidant potential of foodstuffs either at the point of formulation or after different periods of storage under specified conditions.

HPLC simultaneous determination of arbutin, chlorogenic acid and 6'-O-caffeoylarbutin in different parts of Vaccinium dunalianum Wight

Arbutin (1), chlorogenic acid (2) and 6'-O-caffeoylarbutin (3) are three major components in Vaccinium dunalianum Wight with various promising bioactivities. A reliable, reproducible and accurate method for simultaneous and quantitative determination of 1-3 is developed by RP-HPLC analysis. This method should be appropriate for the quality assurance of unprocessed and processed materials of V. dunalianum. The contents of 1-3 in different parts of V. dunalianum from different origins were analysed. The content of 3 was much higher than those of 1 and 2, accounting for up to 31.76% in the dried leaf buds. Moreover, the leaf buds, flower buds and leaves showed a tendency towards higher contents of 1-3 than the other plant parts.

Increased urinary excretion of a 3-(3-hydroxyphenyl)-3-hydroxypropionic acid (HPHPA), an abnormal phenylalanine metabolite of Clostridia spp. in the gastrointestinal tract, in urine samples from patients with autism and schizophrenia

A compound identified as 3-(3-hydroxyphenyl)-3-hydroxypropionic acid (HPHPA) was found in higher concentrations in urine samples of children with autism compared to age and sex appropriate controls and in an adult with recurrent diarrhea due to Clostridium difficile infections. The highest value measured in urine samples was 7500 mmol/mol creatinine, a value 300 times the median normal adult value, in a patient with acute schizophrenia during an acute psychotic episode. The psychosis remitted after treatment with oral vancomycin with a concomitant marked decrease in HPHPA. The source of this compound appears to be multiple species of anaerobic bacteria of the Clostridium genus. The significance of this compound is that it is a probable metabolite of m-tyrosine (3-hydroxyphenylalanine), a tyrosine analog which depletes brain catecholamines and causes symptoms of autism (stereotypical behavior, hyperactivity, and hyper-reactivity) in experimental animals.

Pressure-assisted capillary electrophoresis mass spectrometry using combination of polarity reversion and electroosmotic flow for metabolomics anion analysis

We have developed a method based on capillary electrophoresis (CE) coupled to mass spectrometry (MS) that is a powerful tool for metabolome analysis. In this paper, a simple method for the simultaneous analysis of anionic metabolites such as sugar phosphates, organic acids, nucleotides and CoA compounds based on pressure-assisted capillary electrophoresis coupled to electrospray ionization mass spectrometry (PACE/ESI-MS) is described. The feature of this method is that CE polarity, where the inlet of the capillary is at the anode and the outlet at the cathode, is inverted from conventional CE analysis for anions. Moreover, an ordinary fused silica capillary was chosen instead of a specific cationic polymer-coated capillary (SMILE (+) capillary). A robust and inexpensive analytical method was established from the above-mentioned CE polarity and noncoated fused silica capillary. A trimethylamine acetate electrolyte, pH 10.0, provides a high resolution between isomers. Electrolyte flow using an air pump after electrophoresis enables the comprehensive and simultaneous analyses of sugar phosphates, organic acids, nucleotides and a CoA compound that to date have been impossible to analyze. Our method can be used as a de facto standard for metabolome analysis.

Accumulation of gentisic acid as associated with systemic infections but not with the hypersensitive response in plant-pathogen interactions

In the present work we have studied the accumulation of gentisic acid (2,5-dihydroxybenzoic acid, a metabolic derivative of salicylic acid, SA) in the plant-pathogen systems, Cucumis sativus and Gynura aurantiaca, infected with either prunus necrotic ringspot virus (PNRSV) or the exocortis viroid (CEVd), respectively. Both pathogens produced systemic infections and accumulated large amounts of the intermediary signal molecule gentisic acid as ascertained by electrospray ionization mass spectrometry (ESI-MS) coupled on line with high performance liquid chromatography (HPLC). The compound was found mostly in a conjugated (beta-glucoside) form. Gentisic acid has also been found to accumulate (although at lower levels) in cucumber inoculated with low doses of Pseudomonas syringae pv. tomato, producing a nonnecrotic reaction. In contrast, when cucumber was inoculated with high doses of this pathogen, a hypersensitive reaction occurred, but no gentisic-acid signal was induced. This is consistent with our results supporting the idea that gentisic-acid signaling may be restricted to nonnecrotizing reactions of the host plant (Bellés et al. in Mol Plant-Microbe Interact 12:227-235, 1999). In cucumber and Gynura plants, the activity of gentisic acid as inducing signal was different to that of SA, thus confirming the data found for tomato. Exogenously supplied gentisic acid was able to induce peroxidase activity in both Gynura and cucumber plants in a similar way as SA or pathogens. However, gentisic-acid treatments strongly induced polyphenol oxidase activity in cucumber, whereas pathogen infection or SA treatment resulted in a lower induction of this enzyme. Nevertheless, gentisic acid did not induce other defensive proteins which are induced by SA in these plants. This indicates that gentisic acid could act as an additional signal to SA for the activation of plant defenses in cucumber and Gynura plants.

Simultaneous Determination of Chlorogenic Acid, Caffeic Acid, Ferulic Acid, Protocatechuic Acid and Protocatechuic Aldehyde in Chinese Herbal Preparation by RP-HPLC

In the present study, a reversed phase high performance liquid chromatographic (RP-HPLC) method was established for simultaneous determination of chlorogenic acid, caffeic acid, ferulic acid, protocatechuic acid and protocatechuic aldehyde in a Chinese herbal preparation (Fufang-Pugongying-Mixture). The separation was performed on a Hypersil ODS-2 column by isocratic elution with methanol and 0.2 M acetate buffer (pH 3.6) (15 : 85, v/v) as the mobile phase at the flow-rate of 1.0 ml/min with operating temperature of 30 degrees C, and detection wavelength of 300 nm. A good linear regression relationship between peak-areas and concentrations was obtained over the range of 2-200 microg/ml for the five marker compounds mentioned above. The spike recoveries were within 96.72-104.07%. The variation coefficient (CV) values of the precision were in the range of 0.89-4.50%. Moreover the developed method has reference value for quantitative analysis of Taraxacum, Lonicera and Angelica.

Simultaneous determination of chlorogenic acid, forsythin and arctiin in Chinese traditional medicines preparation by reversed phase-HPLC

A reversed phase (RP)-HPLC method was established for simultaneous determination of chlorogenic acid, arctiin and forsythin in Yinqiao Jiedu Granules, which was a commonly used Chinese herbal medical preparation for treatment of rheum ailments. The determination was based on a gradient elution (A: 1% acetic acid, pH=3.0, B: methanol) on a C18 column and an automatic wavelength switching program, where 325 nm was used for chlorogenic acid and 280 nm for arctiin and forsythin, respectively. Good linearities were obtained over the range of 2-200 mg.l(-1) for the 3 objective compounds. The spike recoveries were within 96.0-97.9%.

Current literature in mass spectrometry

In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of mass spectrometry. Each bibliography is divided into 11 sections: 1 Books, Reviews & Symposia; 2 Instrumental Techniques & Methods; 3 Gas Phase Ion Chemistry; 4 Biology/Biochemistry: Amino Acids, Peptides & Proteins; Carbohydrates; Lipids; Nucleic Acids; 5 Pharmacology/Toxicology; 6 Natural Products; 7 Analysis of Organic Compounds; 8 Analysis of Inorganics/Organometallics; 9 Surface Analysis; 10 Environmental Analysis; 11 Elemental Analysis. Within each section, articles are listed in alphabetical order with respect to author (3 Weeks journals - Search completed at 28th. June 2000)