Exploring the potential of phenolic and antioxidant compounds in new Rosaceae fruits

BACKGROUND

Rosaceae fruits have been used in traditional medicine for the prevention and treatment of diseases. However, these fruits have not extensively been studied regarding their phenolic composition. Thus, this research focuses on the determination of phenolic compounds by high-performance liquid chromatography electrospray ionization time-of-flight mass spectrometry, flavan-3-ols by high-performance liquid chromatography with fluorescence detection, and the antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and ferric reducing antioxidant power of the fruits of five species of genera Crataegus and Sorbus (Rosaceae).

RESULTS

We found a total of 71 phenolic compounds from which 30 were identified in these berries for the first time. Crataegus monogyna and Crataegus laciniata revealed higher total phenolic and flavan-3-ol contents than the other species and the highest antioxidant activities.

CONCLUSIONS

Therefore, the fruits evaluated have demonstrated to be important sources of bioactive compounds with huge potential for being used in nutraceutical or food scopes. Additional studies could be needed to evaluate the influence of the different production areas on the phenolic content. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Crataegus pentagyna willd. Fruits, leaves and roots: phytochemicals, antioxidant and antimicrobial potentials

BACKGROUND

The hawthorn has recently been used as a popular herbal medicine in food applications and phytotherapy, especially for the cardiovascular system.

METHODS

In this study, phytochemicals were evaluated by LC-ESI-MS, GC-MS, and biological activity, including antioxidant (DPPH test) and antibacterial (broth dilution assay), in different extracts of Crataegus pentagyna fruit, leaf, and root.

RESULTS

Globally, 49 phenolics were tentatively identified using HPLC-ESI-MS/MS in the hydro-methanolic extract of the fruit (major apigenin, caffeoylquinic acid derivative, and 4-O-(3'-O-glucopyranosyl)-caffeoyl quinic acid), 42 in the leaf (major salicylic acid, naringenin-6-C-glucoside, and naringin), and 33 in the root (major naringenin-7-O-neohesperidoside, isovitexin-2″-O-rhamnoside, and 4-O-(3'-O-glucopyranosyl)-caffeoyl quinic acid). The major group compounds analyzed by GC-MS in petroleum ether extracts were hydrocarbons (63.80%) and fatty acids and their derivatives (11.77%) in fruit, hydrocarbons (49.20%) and fatty acids and their derivatives (13.85%) in leaf, and hydrocarbons (53.96%) and terpenes (13.06%) in root. All samples exhibited promising phytochemical profile (total phenol, flavonoid, phenolic acid, and anthocyanin), antioxidant and antibacterial capacities, especially in hydro-methanolic extract of fruit (210.22 ± 0.44 mg GAE/g DE; 79.93 ± 0.54 mg QE/g DE; 194.64 ± 0.32 mg CAE/g DE; 85.37 ± 0.13 mg cyanidin 3-glucoside/100 g FW; DPPH: 15.43 ± 0.65 µg/mL; MIC: 0.15-0.62 µg/mL; and MBC: 0.62-1.25 mg/mL), followed by the leaf and root extracts, respectively. The PCA and heatmap analysis results distinguished metabolite profile differences for samples.

CONCLUSION

The results of the present work provide scientific support for C. pentagyna as antimicrobial agents and natural antioxidants in human health and food preservation.

Comprehensive Analysis of the Chemical and Bioactivity Profiles of Endemic Crataegus turcicus Dönmez in Comparison with Other Crataegus Species

Crataegus turcicus is a plant endemic to Türkiye. For the first time, this study aimed to comparatively assess its flower-bearing branches, leaves, and fruits with other well-known Crataegus species (C. monogyna, C. pentagyna, and C. orientalis) in terms of chemical composition and bioactivity studies to evaluate its potential use as a food supplement. Firstly, the contents of total phenolics (TPC), flavonoids (TFC), proanthocyanidin (TPAC), and anthocyanin (TAC) in different plant parts of Crataegus species were evaluated. The highest TPAC was found in the hydroalcoholic extract of C. turcicus flower-bearing branches. Moreover, all plant parts had comparatively higher amounts of TPC, TFC, and TAC compared to other Crataegus species. The chemical screening by high-performance thin-layer chromatography (HPTLC) resulted that C. turcicus parts were rich with chlorogenic acid, neochlorogenic acid, quercetin and vitexin derivatives, epicatechin, procyanidin, etc., and their quantities were evaluated by high-performance liquid chromatography (HPLC). In terms of several in vitro antioxidant activity outcomes, the flower-bearing branches of C. turcicus showed the highest antioxidant activity by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) test among the assessed antioxidant assays. Additionally, hydroalcoholic extracts of C. turcicus significantly decreased LPS-induced nitric oxide, tumor necrosis factor-alpha, and interleukin-6 production more potently than indomethacin (positive control). In addition to its remarkable anti-inflammatory activity, C. turcicus showed analgesic activity by reducing prostaglandin E2 levels.

Phenolic Compound Profile and Antioxidant Capacity of Flax (Linum usitatissimum L.) Harvested at Different Growth Stages

The profile of phenolic compounds changes during the growth of a plant and this change affects its antioxidant potential. The aim of this research has been to find the growth stage of flax with the highest antioxidant capacity, and to determine the phenolic compounds responsible for such a capacity. Flax was harvested in six growth stages: from stem extension to mature seeds. The phenolic compounds were identified using LC-TOF-MS and quantified in an extract and in the fresh matter (FM) of each growth stage. The radical scavenging activity against ABTS^•+ and DPPH^•, the ferric-reducing antioxidant power (FRAP), and the antioxidant activity in the β-carotene-linoleic acid emulsion system were determined. Mono- and di-C-glycosyl flavones were found to be the most abundant phenolics of the aerial parts of flax, which also showed the highest content of isoorientin (210-538 µg/g FM). Coniferin, its derivative, and hydroxycinnamic acid derivatives were also detected. The plant was richer in flavone C-glycosides from stem extension to seed ripening (1105-1413 µg/g FM) than at the mature seed stage (557 µg/g FM). Most of the individual flavone C-glycoside contents in the extracts decreased when increasingly older plants were considered; however, the isoorientin content did not change significantly from the steam extension to the seed ripening stages. The antiradical activity against ABTS^•+ and FRAP was higher for the aerial parts of the flax harvested at the flowering, brown capsule, and seed ripening stages, mainly due to the presence of flavone C-glycosides. The oxidation of β-carotene-linoleic acid emulsion was instead inhibited more effectively by the extracts from plants at the brown capsule and mature seed stages. Coniferin and its derivative were significantly involved in this activity. The extracts from the aerial parts of the flax harvested from flowering to seed ripening could be a valuable source of flavone C-glycosides for use as nutraceuticals and components of functional foods.

Phenolic Compounds from New Natural Sources-Plant Genotype and Ontogenetic Variation

Phenolic compounds (PCs) are widespread secondary metabolites with potent biological activity. Their sources are mainly plants from cultivated and natural states, providing valuable protective and health-promoting extracts. The wide biological activity of PCs (antioxidant, anti-inflammatory, antimicrobial, antiatherosclerotic, antidiabetic, antiallergic, prebiotic, antimutagenic) means that new sources of PCs are constantly being sought, as exemplified by extracting these compounds from tissue culture or agricultural by-products. Plant phenols show marked qualitative and quantitative variation not only at different genetic levels (between and within species and clones) but also between different physiological and developmental stages. Assessing genetic and seasonal variations in phenolic content and activity allows for selecting the best time to harvest the plant. Learning about the causes of PCs' variability and putting this knowledge into practice can significantly increase PCs' yields and extract the most valuable compounds. The health-promoting properties resulting from consuming products rich in plant PCs are undeniable, so it is worth promoting high-phenolic products as a regular diet. This paper presents an overview of different sources of PCs for use as potential therapeutic alternatives. Additionally, factors of variation in the phenolic complex at the genome and ontogeny levels, relevant in practical terms and as a basis for further scientific research, are presented.

Procyanidins: From Agro-Industrial Waste to Food as Bioactive Molecules

Procyanidins are an important group of bioactive molecules known for their benefits to human health. These compounds are promising in the treatment of chronic metabolic diseases such as cancer, diabetes, and cardiovascular disease, as they prevent cell damage related to oxidative stress. It is necessary to study effective extraction methods for the recovery of these components. In this review, advances in the recovery of procyanidins from agro-industrial wastes are presented, which are obtained through ultrasound-assisted extraction, microwave-assisted extraction, supercritical fluid extraction, pressurized fluid extraction and subcritical water extraction. Current trends focus on the extraction of procyanidins from seeds, peels, pomaces, leaves and bark in agro-industrial wastes, which are extracted by ultrasound. Some techniques have been coupled with environmentally friendly techniques. There are few studies focused on the extraction and evaluation of biological activities of procyanidins. The identification and quantification of these compounds are the result of the study of the polyphenolic profile of plant sources. Antioxidant, antibiotic, and anti-inflammatory activity are presented as the biological properties of greatest interest. Agro-industrial wastes can be an economical and easily accessible source for the extraction of procyanidins.

Setup of an Ultrasonic-Assisted Extraction to Obtain High Phenolic Recovery in Crataegus monogyna Leaves

Hawthorn leaves are a rich source of phenolic compounds that possess beneficial activities for human health. Ultrasonic-assisted extraction (UAE) is an extraction technique frequently used for the isolation of phenolic compounds in plants. Thus, in this study, a Box–Behnken design was used to optimize UAE conditions such as the percentage of acetone, the extraction time and solvent-to-solid ratio (v/w) in order to obtain the maximum content of total compounds by Folin–Ciocalteu and the maximum in vitro antioxidant activity by DPPH, ABTS and FRAP assays in Crataegus monogyna leaves. The optimum conditions to obtain the highest total phenolic content and antioxidant activities were 50% acetone, 55 min and 1/1000 (w/v). A total of 30 phenolic compounds were identified and quantified in C. monogyna leaf extract obtained at these optimum UAE conditions. HPLC-MS allows the identification and quantification of 19 phenolic compounds and NP-HPLC-FLD analyses showed the presence of 11 proanthocyanidins. According to the results, the most concentrated phenolic compounds in C. monogyna leaf extract obtained at optimum UAE conditions were phenolic acid derivatives such as protocatechuic acid-glucoside, dihydroxy benzoic acid pentoside and chlorogenic acid, flavones such as 2″-O-rhamnosyl-C-hexosyl-apigenin, flavonols such as hyperoside and isoquercetin and proanthocyanidins such as monomer and dimer. As a result, the optimized UAE conditions could be used to obtain an extract of C. monogyna leaves enriched with phenolic compounds.

Sunflower (Helianthus annuus L.) Plants at Various Growth Stages Subjected to Extraction-Comparison of the Antioxidant Activity and Phenolic Profile

The aim of this study was to evaluate the differences in the antioxidant activity and phenolic profile of sunflower (Helianthus annuus L.) extracts obtained from the aerial parts of plants harvested at five growth stages. In vitro assays were used to determine the antioxidant activity, i.e., ABTS•+ and DPPH• scavenging activity, the ferric-reducing antioxidant power (FRAP) and the ability to inhibit β-carotene-linoleic acid emulsion oxidation. Phenolic compounds, such as mono- and dicaffeoylquinic acid isomers and caffeic acid hexose, were identified using the LC-TOF-MS/MS technique. The predominant compound during the growth cycle of the plant was 3,5-di-O-caffeoylquinic acid, whose content was the highest at the mid-flowering stage. The total phenolic content was also the highest in sunflowers at the mid-flowering stage. The main phenolic compound contents were closely correlated with ABTS•+ and DPPH• scavenging activity and FRAP. No significant correlation was found between the total phenolic content and the antioxidant activity in the emulsion system. The highest antiradical activity and FRAP were generally determined in older plants (mid-flowering and late flowering stages). In conclusion, the aerial parts of sunflowers, in particular those harvested at the mid-flowering stage, are a good plant material from which to obtain phenolic compound extracts, albeit mainly of one class (esters of caffeic acid and quinic acid), with high antioxidant activity.