Effect of Sunlight Exposure on Anthocyanin and Non-Anthocyanin Phenolic Levels in Pomegranate Juices by High Resolution Mass Spectrometry Approach

Metabolomics and molecular networking approach for exploring the anti-diabetic activity of medicinal plants

Metabolomics and molecular networking approaches have expanded rapidly in the field of biological sciences and involve the systematic identification, visualization, and high-throughput characterization of bioactive metabolites in natural products using sophisticated mass spectrometry-based techniques. The popularity of natural products in pharmaceutical therapies has been influenced by medicinal plants with a long history of ethnobotany and a vast collection of bioactive compounds. Here, we selected four medicinal plants Cleistocalyx operculatus, Terminalia chebula, Ficus lacor, and Ficus semicordata, the biochemical characteristics of which remain unclear owing to the inherent complexity of their plant metabolites. In this study, we aimed to evaluate the potential of these aforementioned plant extracts in inhibiting the enzymatic activity of α-amylase and α-glucosidase, respectively, followed by the annotation of secondary metabolites. The methanol extract of Ficus semicordata exhibited the highest α-amylase inhibition with an IC50 of 46.8 ± 1.8 μg mL-1, whereas the water fraction of Terminalia chebula fruits demonstrated the most significant α-glucosidase inhibition with an IC50 value of 1.07 ± 0.01 μg mL-1. The metabolic profiling of plant extracts was analyzed through Liquid Chromatography-Mass Spectrometry (LC-HRMS) of the active fractions, resulting in the annotation of 32 secondary metabolites. Furthermore, we applied the Global Natural Product Social Molecular Networking (GNPS) platform to evaluate the MS/MS data of Terminalia chebula (bark), revealing that there were 205 and 160 individual ion species observed as nodes in the methanol and ethyl acetate fractions, respectively. Twenty-two metabolites were tentatively identified from the network map, of which 11 compounds were unidentified during manual annotation.

Comprehensive HRMS Chemical Characterization of Pomegranate-Based Antioxidant Drinks via a Newly Developed Suspect and Target Screening Workflow

Antioxidants play a significant role in human health, protecting against a variety of diseases. Therefore, the development of products with antioxidant activity is becoming increasingly prominent in the human lifestyle. New antioxidant drinks containing different percentages of pomegranate, blackberries, red grapes, and aronia have been designed, developed, and manufactured by a local industry. The comprehensive characterization of the drinks' constituents has been deemed necessary to evaluate their bioactivity. Thus, LC-qTOFMS has been selected, due to its sensitivity and structure identification capability. Both data-dependent and -independent acquisition modes have been utilized. The data have been treated according to a novel, newly designed workflow based on MS-DIAL and MZmine for suspect, as well as target screening. The classical MS-DIAL workflow has been modified to perform suspect and target screening in an automatic way. Furthermore, a novel methodology based on a compiled bioactivity-driven suspect list was developed and expanded with combinatorial enumeration to include metabolism products of the highlighted metabolites. Compounds belonging to ontologies with possible antioxidant capacity have been identified, such as flavonoids, amino acids, and fatty acids, which could be beneficial to human health, revealing the importance of the produced drinks as well as the efficacy of the new in-house developed workflow.

Physicochemical properties of Tunisian pomegranate fruits Punica granatum L. grown at different climatic zones of Yunnan, China

The artificial cultivation of Mengzi pomegranate has been conducted on a large area for more than 30 years in Yunnan, China. As the quality of pomegranate cultivars have degraded seriously, new cultivars have gradually been introduced to meet market demand. Comparative quality evaluation of different pomegranate varieties is beneficial to guide cultivar improvement and cultural program modification. The present study investigated the differences of physicochemical characteristics of the introduced Tunisian soft-seed pomegranate in different climate zones in Yunnan, China. Meanwhile, the differences between native cultivars (Tian guan yan (TGY) and Tian lv zi (TLZ)) and introduced cultivar were also compared. It was found that the Tunisian soft-seed pomegranate grown in Huize (Tunisian pomegranate in Huize, TH) in the temperate plateau monsoon climate belt had the highest fruit weight, % of seed, TAC, TPC, TSS, amino acids, and Mn, and had the lowest organic acids and Na. While grown in the subtropical monsoon climate area Shiping (Tunisian pomegranate in Shiping, TS), the Tunisian pomegranate fruits had the highest amounts of Cu. Commonly, there were significant correlations between cultivation climate regions and fruit properties. The contents of the TSS, TAC, TPC, flavor amino acids and organic acids varied with planted climate zones. The introduced Tunisian soft-seed pomegranate has comparable levels of physicochemical characteristics with the local main cultivars in the same planted climate region. Tunisian soft-seed pomegranate of higher quality can be obtained in Huize area. Collectively, the climate difference and cultivar shift have a significant effect on pomegranate production in Yunnan, and pomegranate with good quality can be obtained by using proper cultivars in optimized climate zone.

Comparative metabolomics reveal intraspecies variability in bioactive compounds of different cultivars of pomegranate fruit (Punica granatum L.) and their waste by-products

BACKGROUND

The different parts of pomegranate fruit are considered a powerful mixture of bioactive compounds yet the peels and pulps of the fruits are usually discarded and considered as industrial waste. In this work, ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-QqQ-MS) was utilized for metabolomics analysis of different parts (peel, pulp, seed and juice) of pomegranate fruit cultivars to verify possible variations among the fruits and their waste products as potential sources of functional constituents.

RESULTS

Orthogonal projection to latent structure-discriminant analysis (OPLS-DA) coefficient-plot showed enrichment of phenolic compounds such as punicalagin and ellagic acid derivatives in pulp samples while seeds class was enriched in phlorizin, catechin and quercetin, juice class showed abundance of naringenin and pelargonidin-3-pentoside while peels were enriched in anthocyanins and flavonoids including cyanidin diglycoside, quercetin and luteolin glycosides. Although the juice samples of almost all tested cultivars showed remarkable cytotoxic activity, the pulp samples, particularly the Manfalouti cultivar, exhibited the most potent [half maximal inhibitory concentration (IC₅₀ ) = 2.367 ± 0.14 μg/mL in MCF-7, IC₅₀  = 3.854 ± 0.23 μg/mL in Hep-G2 cell lines]. OPLS models were constructed for determination of cytotoxicity-associated metabolites among where the coefficients plots revealed tannins; granatin A, ellagic acid derivatives, punicalagin α and β, in addition to anthocyanins and phenolic compounds; cyanidin diglycoside, quercetin, phlorizin, 3-O-caffeoylquinic acid, naringenin and liquiritin were more pertinent with cytotoxicity of the different parts of pomegranate fruit.

CONCLUSION

The results obtained allow for the full utilization of the resources of pomegranate fruit and its industrial waste as sources of bioactive compounds. © 2022 Society of Chemical Industry.

Polyphenol Characterization and Antioxidant Activity of Grape Seeds and Skins from Sicily: A Preliminary Study

The interest in the consumption of health-promoting foods has led to identifying derivatives of the wine industry as products to increase the functional properties of different foods or to design new functional foods. The main goal of this study is to characterize and valorize byproducts and wastes of Sicilian grapes as new sources of bioactive components, from the perspective of a circular economy and a biorefinery approach. In particular, this research investigated: 1. the total phenolic content and antioxidant activities and 2. the phenolic profiles of free and bound fractions of defatted grape seeds and red grape skins from Sicily. Defatted grape seeds (DGS) and red grape skins (RGSK) are rich in phenolic compounds. Twenty biophenols were found in the defatted seeds and red grape skins. Particularly interesting were the results obtained after basic hydrolysis, which allowed the release of biophenols from the matrix. The degreased grape seeds showed p-coumaric acid levels at 4641.65 µg g−1, gallic acid at 2649.23 µg g−1, and caffeic acid at 1474.13 µg g−1, along with appreciable quantities of myricetin, epicatechin, and quercetin. As a sustainable approach, the reuse and the value added of the byproducts and wastes of grapes grown in Sicily is shown, which makes possible new applications in different fields, i.e., nutraceuticals.

Variability in the Beneficial Effects of Phenolic Compounds: A Review

When analysing the beneficial effects of phenolic compounds, several factors that exert a clear influence should be taken into account. The content of phenolic compounds in foods is highly variable, directly affecting individual dietary intake. Once ingested, these compounds have a greater or lesser bioaccessibility, defined as the amount available for absorption in the intestine after digestion, and a certain bioavailability, defined as the proportion of the molecule that is available after digestion, absorption and metabolism. Among the external factors that modify the content of phenolic compounds in food are the variety, the cultivation technique and the climate. Regarding functional foods, it is important to take into account the role of the selected food matrix, such as dairy matrices, liquid or solid matrices. It is also essential to consider the interactions between phenolic compounds as well as the interplay that occurs between these and several other components of the diet (macro- and micronutrients) at absorption, metabolism and mechanism of action levels. Furthermore, there is a great inter-individual variability in terms of phase II metabolism of these compounds, composition of the microbiota, and metabolic state or metabotype to which the subject belongs. All these factors introduce variability in the responses observed after ingestion of foods or nutraceuticals containing phenolic compounds.

Anthocyanins from Pomegranate (Punica granatum L. ) and Their Role in Antioxidant Capacities in Vitro

As phytochemicals, anthocyanins are not only responsible for the diverse colors in nature, but are associated with broad-spectrum health-promoting effects for human beings. Pomegranate is abundant in anthocyanins which possess high antioxidant capacities. However, the pomegranate anthocyanins profile and their contributions to antioxidant capacities are not fully depicted. The purpose of this paper is to review anthocyanins from pomegranate as important antioxidants. Total anthocyanin content (TAC) and six major components vary greatly with intrinsic and extrinsic factors. In pomegranate, anthocyanins mainly acted as primary antioxidants, while their action as secondary antioxidants were not conclusive. The antioxidant potentials of anthocyanins were significantly affected by factors especially chemical structure and detection assays in vitro. The current knowledge may provide insights into potential applications for pomegranate anthocyanins based on their antioxidant activities.

Biological Activities of Plant Food Components: Implications in Human Health

Scientific data and epidemiological evidence collected over the last fifty years have shown that nutrition plays a decisive role in human health [...].