Identification of compounds from chufa (Eleocharis dulcis) peels with inhibitory acrylamide formation activity

Isolation and identification of active components from Grifola frondosa and its anti-EV71 virus effect

BACKGROUND

It is reported that anti-enterovirus 71 (EV71) drugs have some side effects on human health. Notably, fungi plays a crucial role in promoting human health and anti-virus. Grifola frondosa is a type of large medicinal and edible fungi, rich in active substances. The present study aimed to investigate the anti-EV71 effect of G. frondosa and the potential active substances.

RESULTS

In the present study, the water extract of G. frondosa was subjected to ethanol precipitation to obtain the water-extracted supernatant of G. frondosa (GFWS) and water-extracted precipitation of G. frondosa. Their inhibitory effects on EV71 virus were studied based on a cell model. The results showed that GFWS had stronger security and anti-EV71 effects. In addition, the chemical constituents of GFWS were identified by ultra-high performance liquid chromatography-tandem mass spectrometry, which were selected for further separation and purification. Three compounds, N-butylaniline, succinic acid and l-tryptophan, were isolated from GFWS by NMR spectroscopy. It is noteworthy that N-butylaniline and l-tryptophan were isolated and identified from the G. frondosa fruiting bodies for the first time. Our study found that l-tryptophan has anti-EV71 virus activity, which reduced EV71-induced apoptosis and significantly inhibited the replication process after virus adsorption. Furthermore, it could also bind to capsid protein VP1 to prevent the virus from attaching to the cells.

CONCLUSION

l-tryptophan was an inhibitor of the EV71 virus, which could be used in infant nutrition and possibly provide a new drug to treat hand, foot and mouth disease. © 2024 Society of Chemical Industry.

Flavonoid glycosides and ellagic acid cognates from defatted African mango (Irvingia gabonensis) seed kernel

Seventeen compounds of diverse classes including four flavonoid glycosides, five ellagic acid derivatives, and eight other metabolites were isolated from the methanolic extract of the defatted seed kernel of Irvingia gabonensis. Among the isolates, quercetin 3-O-methyl-4'-[α-L-rhamnopyranosyl-(1→3)]-O-α-L-rhamnopyranoside (1) and 3,3'-di-O-methyl-4'-O-α-L-rhamnopyranosylellagic acid 4-sulfate ester (5) were found to be previously undescribed. Structure elucidation was mainly achieved by the interpretation of 1D and 2D NMR and HRESIMS spectral data. Though compound 6 was previously reported, its 13C NMR data is being reported herein for the first time. To the best of our literature search knowledge, this is the first phytochemical report on I. gabonensis seed kernels.

Potent insecticidal activity of Eleocharis dulcis (Burm. f.) Trin peel extract and its main components against aphids

BACKGROUND

Aphids are significant pests of cash crops and food farm crops. Botanical insecticides are safe for aphid control, especially for organic farming. In this study, Eleocharis dulcis (Burm. f.) Trin. peel extract (EDPE), a new botanical insecticide, was investigated for its active compositions against several agricultural aphids.

RESULTS

The results showed that the EDPE had high insecticidal activity against Sitobion avenae Fabricius, Aphis gossypii Glover, Megoura crassicauda Mordvilko, and Acyrthosiphon pisum Harris, with half-lethal concentration (LC₅₀ ) values of 95.92, 81.04, 140.31, and 255.73 mg/L after 48 h of treatment. In the pot culture assay, the aphicidal effects of 25% EDPE soluble liquid (SL) at a concentration of 0.016% were 68.98 ± 5.61%, 79.33 ± 8.27%, and 88.82 ± 3.91% after the first, third, and seventh days of treatment, respectively. Nine compounds were identified by bioactivity-directed fractionation: 4',5'-dimethoxy-6,6-dimethylpyranoisoflavone (1), 3-methoxy-4-hydroxylonchocarpin (2), 4-hydroxylonchocarpin (3), 4-methoxylonchocarpin (4), barbigerone (5), lonchocarpusone (6), 6a,12a-dehydrodeguelin (7), 13-homo-13-oxa-6a, 12a-dehydrodeguelin (8) and deguelin (9). Among them, 4-hydroxylonchocarpin (3) showed the highest aphidicidal activity against M. crassicauda, S. avenae, and A. pisum, with LC₅₀ values of 97.24, 140.63, and 112.31 mg/L, respectively.

CONCLUSION

These data contribute to a better understanding of the aphicidal activity of EDPE and its main component, 4-hydroxylonchocarpin. This will help to develop new botanical insecticides to contro aphids. © 2022 Society of Chemical Industry.

Identification of compounds from chufa (Eleocharis dulcis) peels by widely targeted metabolomics

The Chinese water chestnut (CWC) is among the most widespread and economically important vegetables in Southern China. There are two different types of cultivars for this vegetable, namely, big CWC (BCWC) and small CWC (SCWC). These are used for different purposes based on their metabolic profiles. This study aimed to investigate the metabolite profile of CWC and compare the profiles of peels collected in different harvest years using ultraperformance liquid chromatography/mass spectrometry (UPLC-MS)-based metabolomics analysis. Three hundred and twenty-one metabolites were identified, of which 87 flavonoids, 25 phenylpropanoids, and 33 organic acids and derivatives were significantly different in the content of the two varieties of BCWC and SCWC. The metabolite profiles of the two different cultivars were distinguished using principle component analysis (PCA) and orthogonal projections to latent structures discriminant analysis, and the results indicated differences in the metabolite profile of Eleocharis dulcis (Burm. f.) Trin. ex Hensch. Three isomers of hydroxycoumarin, namely, O-feruloyl-4-hydroxycoumarin, O-feruloyl-3-hydroxycoumarin, and O-feruloyl-2-hydroxycoumarin, exhibited increased levels in BCWC, while p-coumaric acid and vanillic acid did not show any significant differences in their content in BCWC and SCWC peels. This study, for the first time, provides novel insights into the differences among metabolite profiles between BCWC and SCWC.

Taste Compound Generation and Variation in Chinese Water Chestnut (Eleocharis dulcis (Burm.f.) Trin. ex Hensch.) Processed with Different Methods by UPLC-MS/MS and Electronic Tongue System

Chinese water chestnut (CWC) is popular among consumers due to its unique flavor and crisp and sweet taste. Thus far, the key substances affecting the taste compound of CWC are still unclear. In this study, we used UPLC-MS/MS and an electronic tongue system to study the effects of four typical steaming and cooking methods, cooking without peel for 10 min (PC), steaming without peel for 15 min (PS), cooking with peel for 30 min (WPC), steaming with peel for 30 min (WPS), on the taste compound generation and variation of CWC, and revealed the secret of its crisp and sweet taste. The results show that the electronic tongue can effectively identify the taste profile of CWC, and the effective tastes of CWC were umami, bitterness, saltiness, and sweetness. We screened 371 differential compounds from 640 metabolic species. Among them, nucleotides and their derivatives, carbohydrates, organic acids and their derivatives, and amino acids and their derivatives are closely related to the key taste of CWC, and these compounds affected the taste of CWC through six related metabolic pathways: oxidative phosphorylation and purine metabolism; alanine, aspartate, and glutamate; bile secretion; amino sugar and nucleotide sugar metabolism; the phenylpropane pathway; and toluene degradation. This study reveals the potential metabolic causes of taste compound generation and variation in the taste of CWC.

Eleocharis dulcis corm: phytochemicals, health benefits, processing and food products

Eleocharis dulcis, an aquatic plant belonging to Cyperaceae family, is indigenous to Asia, and also occurs in tropical Africa and Australia. The edible corm part of E. dulcis is a commonly consumed aquatic vegetable with a planting area of 44.46 × 10³ hm² in China. This work aims to explore the potential of E. dulcis corm for use as a new food source for sufficient nutrients and health benefits by reviewing its nutrients, phytochemicals, functions, processing and food products. Eleocharis dulcis corm contains starches, dietary fibers, non-starch polysaccharides, proteins, amino acids, phenolics, sterols, puchiin, saponins, minerals and vitamins. Among them, phenolics including flavonoids and quinones could be the major bioconstituents that largely contribute to antioxidant, anti-inflammatory, antibacterial, antitumor, hepatoprotective, neuroprotective and hypolipidemic functions. Peel wastes of E. dulcis corm tend to be enriched in phenolics to a much higher extent than the edible pulp. Fresh-cut E. dulcis corm can be consumed as a ready-to-eat food or processed into juice for beverage production, and anti-browning processing is a key to prolonging shelf life. Present food products of E. dulcis corm are centered on various fruit and vegetable beverages, and suffer from single categories and inadequate development. In brief, underutilized E. dulcis corm possesses great potential for use as a new food source for sufficient nutrients and health benefits. © 2021 Society of Chemical Industry.

Inhibition and interactions of alpha-amylase by daucosterol from the peel of Chinese water chestnut (Eleocharis dulcis)

The alpha-amylase inhibitory effect of daucosterol purified from the peel of Chinese water chestnut (CWC), a common Chinese vegetable, was assessed. The alpha-amylase inhibitory properties were elucidated by enzyme inhibition, fluorescence quenching and molecular docking experiments. It was found that three saponins from CWC peel exhibited potent inhibitory activity on alpha-amylase and daucosterol was found to be the main inhibitory factor against alpha-amylase with a mixed-type mode. Strong fluorescence quenching of alpha-amylase was observed under static fluorescence quenching with hydrophobic interactions with daucosterol. Molecular docking revealed that the conformation of daucosterol in the high-affinity sites I and II of alpha-amylase was optimum, and hydrophobic interactions were produced by daucosterol aglycone, and hydrogen bonding by the β-D-glucopyranosyl residue. Ingested daucosterol suppressed the elevation of blood glucose levels through inhibition of alpha-amylase in the small intestine in starch-loaded mice. This study provides data supporting the potential benefit of daucosterol from CWC peel in the treatment of diabetes.

Olive Fruit and Leaf Wastes as Bioactive Ingredients for Cosmetics-A Preliminary Study

Olea europaea cultivar, native in the Mediterranean basin, has expanded worldwide, mainly due to the olive oil industry. This expansion is attributed to the benefits of olive oil consumption, since this product is rich in nutritional and bioactive compounds. However, the olive industry generates high amounts of wastes, which could be related to polluting effects on soil and water. To minimize the environmental impact, different strategies of revalorization have been proposed. In this sense, the aim of this work was to develop high cosmetic value added oleuropein-enriched extracts (O20 and O30), a bioactive compound from olive byproducts, performing a comprehensive characterization using high performance liquid chromatography coupled to mass spectrometry and evaluate their bioactivity by in vitro assays. A total of 49 compounds were detected, with oleuropein and its derivatives widely found in O30 extract, whereas iridoids were mainly detected in O20 extract. Moreover, 10 compounds were detected for the first time in olive leaves. Both extracts demonstrated strong antioxidant and antiradical activities, although O30 showed higher values. In addition, radical oxygen and nitrogen species scavenging and enzyme inhibition values were higher in O30, with the exception of HOCl and hyaluronidase inhibition assays. Regarding cell viability, olive byproduct extracts did not lead to a decrease in keratinocytes viability until 100 µg/mL. All data reported by the present study reflect the potential of industrial byproducts as cosmetic ingredients.

Comparison of flavonoids and phenylpropanoids compounds in Chinese water chestnut processed with different methods

Different processing methods of Chinese water chestnut (CWC; Eleocharis dulcis (Burm.f.) Trin. ex Hensch.) steaming with skin (WPC), cooking with skin (WPS), steaming with peeling (PS), fresh cutting (FF) and cooking with peeling (PC) were compared. Liquid chromatography-mass spectrometry was used to analyze the metabolic profiles of the processed samples. A total of 454 metabolites, including 123 flavonoids and 57 phenylpropanoids, were characterized. The flavonoid and phenylpropanoid profiles were distinguished using PCA. Eighteen flavonoids and six phenylpropanoids were detected and quantitated in the WPC and WPS samples but not in the FF, PC and PS samples. In addition to the O-hexoside of tricin, kaempferol and luteolin were the predominant flavonoids in the WPC and WPS samples, and all three compounds were higher in the WPC and WPS samples than in the FF sample. This study provides new results regarding differences in the metabolite profile of CWC processed with different methods.

Structural characterization of polysaccharides with potential antioxidant and immunomodulatory activities from Chinese water chestnut peels

Chinese water chestnut peels are a kind of vegetable processing waste containing many active components such as polysaccharides, the structure of which remains unknown. To elucidate the structure of polysaccharides from Chinese water chestnut peels, two polysaccharides named WVP-1 and WVP-2 were isolated. WVP-1 (3.16 kDa) consisted of mannose (1.75 %), glucose (84.69 %), galactose (6.32 %), and arabinose (7.24 %), while WVP-2 (56.97 kDa) was composed of mannose (3.18 %), rhamnose (1.52 %), glucuronic acid (1.42 %), galacturonic acid (4.83 %), glucose (11.51 %), galactose (36.02 %), and arabinose (41.53 %). Linkage and NMR data indicated that WVP-1 was composed mainly of →4)-α-d-Glcp(1→ and a certain proportion of →3)-β-d-Glcp-(1→, including linear and branched polysaccharides simultaneously. WVP-2 was a pectin-like polysaccharide with →4)-α-d-GalpA6Me-(1→ units and the branch points of →3,4)-α-l-Arap-(1→, →3,6)-β-d-Galp-(1→. WVP-2 exhibited stronger potential antioxidant and immunomodulatory activities than WVP-1 in vitro. These results provide a foundation for the further study of polysaccharides from Chinese water chestnut peels.