LC-DAD-ESI-MS/MS-based phenolic profiling of St John’s Wort Teas and their antioxidant activity: Eliciting infusion induced changes

Exploring the Impact of Infusion Parameters and In Vitro Digestion on the Phenolic Profile and Antioxidant Capacity of Guayusa (Ilex guayusa Loes.) Tea Using Liquid Chromatography, Diode Array Detection, and Electrospray Ionization Tandem Mass Spectrometry

Guayusa tea is derived from the leaves of the Ilex guayusa Loes. plant, which is native to the Amazon rainforest. Beyond its pleasant sensory properties, Guayusa tea is rich in antioxidants, phenolics, and minerals. In this study, the effects of infusion time, temperature, and solvent conditions on the color, antioxidant capacity, total phenolic content, phenolic profile, and antimicrobial activity of Guayusa (Ilex guayusa Loes.) tea were investigated. Guayusa tea samples were prepared using two different solvents, ethanol and water, with 4, 6, and 8-h infusions at 60 and 70 °C. Liquid chromatography, diode array detection, and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MS/MS) were used to determine a comprehensive profile of phenolic compounds and to detect differences due to infusion conditions. Moreover, after the Guayusa tea infusion with the highest bioactive properties was determined, the effects of in vitro gastrointestinal digestion on the total phenolic content, antioxidant capacity, and phenolic compounds of the Guayusa tea infusion were measured. Phenolic profile analysis identified 29 compounds, among which chlorogenic acid and its derivatives were predominant. The increase in infusion time was correlated with an elevation in total phenolic content. Significant differences were observed between water and ethanol infusions of Guayusa in terms of phenolics and antioxidants. The total amount of phenolic compounds in the samples prepared with both solvents was found to increase after oral intake, depending on the digestion stage; meanwhile, the amounts of flavonoid compounds and di-O-caffeoylquinic acid derivatives decreased during digestion.

Soilless Cultivated Halophyte Plants: Volatile, Nutritional, Phytochemical, and Biological Differences

The use of halophyte plants appears as a potential solution for degraded soil, food safety, freshwater scarcity, and coastal area utilization. These plants have been considered an alternative crop soilless agriculture for sustainable use of natural resources. There are few studies carried out with cultivated halophytes using a soilless cultivation system (SCS) that report their nutraceutical value, as well as their benefits on human health. The objective of this study was to evaluate and correlate the nutritional composition, volatile profile, phytochemical content, and biological activities of seven halophyte species cultivated using a SCS (Disphyma crassifolium L., Crithmum maritimum L., Inula crithmoides L., Mesembryanthemum crystallinum L., Mesembryanthemum nodiflorum L., Salicornia ramosissima J. Woods, and Sarcocornia fruticosa (Mill.) A. J. Scott.). Among these species, results showed that S. fruticosa had a higher content in protein (4.44 g/100 g FW), ash (5.70 g/100 g FW), salt (2.80 g/100 g FW), chloride (4.84 g/100 g FW), minerals (Na, K, Fe, Mg, Mn, Zn, Cu), total phenolics (0.33 mg GAE/g FW), and antioxidant activity (8.17 µmol TEAC/g FW). Regarding the phenolic classes, S. fruticosa and M. nodiflorum were predominant in the flavonoids, while M. crystallinum, C. maritimum, and S. ramosissima were in the phenolic acids. Moreover, S. fruticosa, S. ramosissima, M. nodiflorum, M. crystallinum, and I. crithmoides showed ACE-inhibitory activity, an important target control for hypertension. Concerning the volatile profile, C. maritimum, I. crithmoides, and D. crassifolium were abundant in terpenes and esters, while M. nodiflorum, S. fruticosa, and M. crystallinum were richer in alcohols and aldehydes, and S. ramosissima was richer in aldehydes. Considering the environmental and sustainable roles of cultivated halophytes using a SCS, these results indicate that these species could be considered an alternative to conventional table salt, due to their added nutritional and phytochemical composition, with potential contribution for the antioxidant and anti-hypertensive effects.

Electrochemical Characterization of the Antioxidant Properties of Medicinal Plants and Products: A Review

Medicinal plants are an important source of bioactive compounds with a wide spectrum of practically useful properties. Various types of antioxidants synthesized in plants are the reasons for their application in medicine, phytotherapy, and aromatherapy. Therefore, reliable, simple, cost-effective, eco-friendly, and rapid methods for the evaluation of antioxidant properties of medicinal plants and products on their basis are required. Electrochemical methods based on electron transfer reactions are promising tools to solve this problem. Total antioxidant parameters and individual antioxidant quantification can be achieved using suitable electrochemical techniques. The analytical capabilities of constant-current coulometry, potentiometry, various types of voltammetry, and chrono methods in the evaluation of total antioxidant parameters of medicinal plants and plant-derived products are presented. The advantages and limitations of methods in comparison to each other and traditional spectroscopic methods are discussed. The possibility to use electrochemical detection of the antioxidants via reactions with oxidants or radicals (N- and O-centered) in solution, with stable radicals immobilized on the electrode surface, via oxidation of antioxidants on a suitable electrode, allows the study of various mechanisms of antioxidant actions occurring in living systems. Attention is also paid to the individual or simultaneous electrochemical determination of antioxidants in medicinal plants using chemically modified electrodes.

Elucidation of the impact of four different drying methods on the phenolics, volatiles, and color properties of the peels of four types of citrus fruits

BACKGROUND

Citrus fruit peels are considered to be process waste in the fruit juice industry but they are a valuable raw material due to their volatile and bioactive components. Drying is one of the most common methods to preserve this material. In this study, four drying processes were applied to the peels of four kinds of citrus fruits. The drying processes were convective drying (CD), microwave drying (MD), conductive hydro drying (CHD), and freeze drying (FD). The citrus fruits used were orange, bitter orange, grapefruit, and lemon.

RESULTS

The influence of dehydration on the aroma and phenolic composition, microstructure, and color properties were studied in detail. It was determined that drying increased the amount of both phenolics and volatiles in the dried samples. The MD and FD methods better preserved the color and phenolics of the samples, and the MD and CD processes increased the amount of aroma substances.

CONCLUSION

The MD method would be more suitable for drying citrus peels due to its shorter duration and its positive effects on the phenolic and aroma components. © 2022 Society of Chemical Industry.

Impact of Drying Processes on the Nutritional Composition, Volatile Profile, Phytochemical Content and Bioactivity of Salicornia ramosissima J. Woods

Salicornia ramosissima J. Woods is a halophyte plant recognized as a promising natural ingredient and will eventually be recognized a salt substitute (NaCl). However, its shelf-life and applicability in several food matrices requires the use of drying processes, which may have an impact on its nutritional and functional value. The objective of this study was to evaluate the effect of oven and freeze-drying processes on the nutritional composition, volatile profile, phytochemical content, and bioactivity of S. ramosissima using several analytical tools (LC-DAD-ESI-MS/MS and SPME-GC-MS) and bioactivity assays (ORAC, HOSC, and ACE inhibition and antiproliferative effect on HT29 cells). Overall, results show that the drying process changes the chemical composition of the plant. When compared to freeze-drying, the oven-drying process had a lower impact on the nutritional composition but the phytochemical content and antioxidant capacity were significantly reduced. Despite this, oven-dried and freeze-dried samples demonstrated similar antiproliferative (17.56 mg/mL and 17.24 mg/mL, respectively) and antihypertensive (24.56 mg/mL and 18.96 mg/mL, respectively) activities. The volatile composition was also affected when comparing fresh and dried plants and between both drying processes: while for the freeze-dried sample, terpenes corresponded to 57% of the total peak area, a decrease to 17% was observed for the oven-dried sample. The oven-dried S. ramosissima was selected to formulate a ketchup and the product formulated with 2.2% (w/w) of the oven-dried plant showed a good consumer acceptance score. These findings support the use of dried S. ramosissima as a promising functional ingredient that can eventually replace the use of salt.

Variations in the key aroma and phenolic compounds of champignon (Agaricus bisporus) and oyster (Pleurotus ostreatus) mushrooms after two cooking treatments as elucidated by GC-MS-O and LC-DAD-ESI-MS/MS

Volatiles, key odorants, phenolics and antioxidant properties of raw, boiled and oven-cooked champignon and oyster mushrooms were investigated. Total concentration of the volatiles was drastically reduced by both cooking treatments and the lowest contents were found in the oven-cooked sample. Alcohols and terpenes were the dominant aroma groups in the raw champignon and oyster sample, respectively. The highest FD factor (FD = 2048) was found for 1-octen-3-one and methional in raw and boiled champignon samples while the same FD factor was determined in 1-octen-3-ol and methional in raw and boiled oyster samples. It was determined that the phenolics were more abundant in champignon samples than the oyster samples and that the boiling process caused a decrease while oven-cooking resulted in an increase in the amount of phenolics in both varieties. It was revealed that cooking was a crucial factor for the key odorants and phenolics in champignon and oyster mushrooms.

Intelligent evaluation of taste constituents and polyphenols-to-amino acids ratio in matcha tea powder using near infrared spectroscopy

Matcha tea is rich in taste and bioactive constituents, quality evaluation of matcha tea is important to ensure flavor and efficacy. Near-infrared spectroscopy (NIR) in combination with variable selection algorithms was proposed as a fast and non-destructive method for the quality evaluation of matcha tea. Total polyphenols (TP), free amino acids (FAA), and polyphenols-to-amino acids ratio (TP/FAA) were assessed as the taste quality indicators. Successive projections algorithm (SPA), genetic algorithm (GA), and simulated annealing (SA) were subsequently developed from the synergy interval partial least squares (SiPLS). The overall results revealed that SiPLS-SPA and SiPLS-SA models combined with NIR exhibited higher predictive capabilities for the effective determination of TP, FAA and TP/FAA with correlation coefficient in the prediction set (R_p) of R_p > 0.97, R_p > 0.98 and R_p > 0.98 respectively. Therefore, this simple and efficient technique could be practically exploited for tea quality control assessment.

Anti-Inflammatory, Antioxidant, and Anti-Nonalcoholic Steatohepatitis Acylphloroglucinol Meroterpenoids from Hypericum bellum Flowers

In this work, 26 methylated acylphloroglucinol meroterpenoids with diverse skeletons, including 18 new ones (bellumones A-R, 1-18), were identified from the flowers of Hypericum bellum. Their structures including absolute configurations were elucidated by detailed spectroscopic data, calculated electronic circular dichroism (ECD), and X-ray diffraction (XRD). Through methylation at C-5, prenylation with different chain lengths of the acylphloroglucinol-derived core, along with different types of secondary cyclization, type A bicyclic polyprenylated acylphloroglucinols (BPAPs) (1-5 and 19-24) and dearomatized isoprenylated acylphloroglucinols (DIAPs) (6-18 and 25-26) were obtained. The significant results of anti-inflammatory, antioxidant, and anti-nonalcoholic steatohepatitis (anti-NASH) activities suggest its usefulness in daily health care.

Polyphenols composition from leaves of Cuphea spp. and inhibitor potential, in vitro, of angiotensin I-converting enzyme (ACE)

ETHNOPHARMACOLOGICAL RELEVANCE

Cuphea is the largest genus of the Lythraceae family. It is popularly known as "sete-sangrias" in Brazil used in folk medicine as a diuretic, antipyretic, anti-inflammatory, laxative and antihypertensive agent. The raw material of Cuphea has shown promising results in the production of fitotherapics, which are chemically characterized by quercetin core flavonoids.

AIMS OF THE STUDY

Present work aims to investigate the chemical composition of Cuphea calophylla, Cuphea carthagenensis, Cuphea glutinosa and Cuphea racemosa by UHPLC-MS using ESI-Q-TOF, and also to investigate the inhibition of angiotensin-converting enzyme (ACE) in vitro.

MATERIALS AND METHODS

Leaves extraction was conducted by an ultrasound-assisted system under the following conditions: 40% ethanol, particle size ≤180 μm, plant:solvent ratio 1:20 (w/v) for 30 min. The leaf extracts were analyzed by UHPLC-MS positive mode ionization. For the inhibition of ACE, the leaf extracts used were obtained from different Cuphea species collected from several regions of Rio Grande do Sul (Brazil).

RESULTS

In total 26 polyphenolic compounds were proposed, which were mostly derived from quercetin, myricetin, and kaempferol. Of these compounds, ten are described in the genus for the first time. The ACE-inhibiting activities are presented in descending order: miquelianin (32.41%), C. glutinosa 1 (31.66%), C. glutinosa 5 (26.32%) and C. carthagenensis 1 (26.12%).

CONCLUSION

The obtained results suggest that the ACE-inhibiting potential may be increased by the interactions among the different phytoconstituents present in the crude extract. These results corroborate with the popular usage of Cuphea genus as diuretic and antihypertensive agents in folk medicine.

Enzyme and Biological Activities of the Water Extracts from the Plants Aesculus hippocastanum, Olea europaea and Hypericum perforatum That Are Used as Folk Remedies in Turkey

Phenolic compounds are secondary metabolites that are found ubiquitously in plants, fruits, and vegetables. Many studies have shown that regular consumption of these compounds could have a positive effect on our health. The aim of this study was to compare the phytochemical contents of the water extracts from three different plants used as folk remedies in Turkey: Aesculus hippocastanum, Olea europaea, and Hypericum perforatum. A liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) analysis was performed to explore the phenolic profiles. The biological activities of these extracts were also evaluated in terms of their antioxidant activities (2,2-diphenyl-1-picrylhydrazyl DPPH, 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid ABTS, Ferric Reducing Antioxidant Power Assay FRAP, cupric ion reducing antioxidant capacity CUPRAC, β-carotene, phosphomolybdenum, and metal chelating) and enzyme inhibitory properties (against acetylcholinesterase, butyrylcholinesterase, and tyrosinase). The aqueous extract of H. perforatum showed the highest levels of total phenolic, flavonoid, and saponin contents. Protocatechuic acid, vanillic acid, verbascoside, hesperidin, hyperoside, apigenin 7-hexosides, and quercetin were the most common compounds found in this species. The results confirm that A. hippocastanum, O. europaea, and H. perforatum represent a potential source of natural-derived molecules with positive properties that could be used as valid starting point for new food supplements, and drugs in the pharmaceutical, cosmetic, and food industries.