Two new tocopherol polymers from the seeds of Euryale ferox

Antibacterial Effect of Euryale ferox Seed Shell Polyphenol Extract on Salmonella Typhimurium

This study aimed to evaluate the effects of Euryale ferox Seed Shell Polyphenol Extract (EFSSPE) on a foodborne pathogenic bacterium. EFSSPE showed antimicrobial activity toward Salmonella Typhimurium CICC 22956; the minimum inhibitory concentration of EFSSPE was 1.25 mg/mL, the inhibition curve also reflected the inhibitory effect of EFSSPE on the growth of S. Typhimurium. Detection of alkaline phosphatase outside the cell revealed that EFSSPE treatment damaged the cell wall integrity of S. Typhimurium. EFSSPE also altered the membrane integrity, thereby causing leaching of 260-nm-absorbing material (bacterial proteins and DNA). Moreover, the activities of succinate dehydrogenase and malate dehydrogenase were inhibited by EFSSPE. The hydrophobicity and clustering ability of cells were affected by EFSSPE. Scanning electron microscopy showed that EFSSPE treatment damaged the morphology of the tested bacteria. These results indicate that EFSSPE can destroy the cell wall integrity and alter the permeability of the cell membrane of S. Typhimurium.

The Ethnopharmacological, Phytochemical, and Pharmacological Review of Euryale ferox Salisb.: A Chinese Medicine Food Homology

Euryale ferox Salisb. (prickly water lily) is the only extent of the genus Euryale that has been widely distributed in China, India, Korea, and Japan. The seeds of E. ferox (EFS) have been categorized as superior food for 2000 years in China, based on their abundant nutrients including polysaccharides, polyphenols, sesquineolignans, tocopherols, cyclic dipeptides, glucosylsterols, cerebrosides, and triterpenoids. These constituents exert multiple pharmacological effects, such as antioxidant, hypoglycemic, cardioprotective, antibacterial, anticancer, antidepression, and hepatoprotective properties. There are very few summarized reports on E. ferox, albeit with its high nutritional value and beneficial activities. Therefore, we collected the reported literature (since 1980), medical classics, database, and pharmacopeia of E. ferox, and summarized the botanical classification, traditional uses, phytochemicals, and pharmacological effects of E. ferox, which will provide new insights for further research and development of EFS-derived functional products.

Extraction, identification, and starch-digestion inhibition of phenolics from Euryale ferox seed coat

BACKGROUND

Euryale ferox is an important cash crop and valuable tonic in traditional medicine. The seeds of E. ferox are rich in starch, which is hard to digest, and the digestion speed is significantly slower than that of rice starch. The goal of this study was to evaluate the effects of E. ferox seed-coat phenolics (EFCPs) on the digestion of E. ferox seed starch.

RESULTS

EFCPs were extracted and identified by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. We optimized the extraction parameters, and the final extraction yield was about 1.49%. We identified seven phenolics from the E. ferox seed-coat extracts: gallic acid, digalloylhexoside, catechin, procyanidin B2, epicatechin, ellagic acid, and epicatechin gallate. Quantitative analysis results showed that the E. ferox seed phenolics mainly distributed in the seed coat and the gallic acid, digalloylhexoside, and epicatechin gallate were three main phenolic compounds. The phenolics displayed strong inhibitory activities on α-glucosidase and α-amylase with an IC₅₀ of 3.25 μg mL^-1 and 1.36 mg mL^-1 respectively. Furthermore, these phenolics could interact with starch by hydrogen bonds, which might make its starch more difficult to digest.

CONCLUSION

Our investigation suggests that the EFCPs can strongly inhibit the digestion of E. ferox seed starch by inhibiting the α-amylase and α-glucosidase activities and interacting with starch by hydrogen bonds; therefore, E. ferox seeds have a promising application prospect in foods for hypoglycemia. © 2023 Society of Chemical Industry.

Euryale ferox, a prominent superfood: Nutritional, pharmaceutical, and its economical importance

Euryale ferox (also known as foxnut), belongs to the family Nymphaeaceae. It is mainly grown in India, China, Japan, and Korea. It is a highly nutritious food, abundant in nutritional and bioactive compounds such as carbohydrates, protein, fiber, vitamins, minerals, and polyphenols. It is considered a functional food owing to its various health benefits such as antidiabetic, antihyperlipidemic, antifatigue, hepatoprotective, cardioprotective, antimelanogenic, etc. E. ferox has immense potential in both food and non-food industries. Regardless of being recognized as a superfood packed with nutritional as well as medicinal properties, it is still neglected, and there has not been much attention given to its cultivation. Therefore, in this review, the potential of E. ferox as a superfood has been explored to enhance its utilization in the development of different foods and make it available outside its growing area. PRACTICAL APPLICATIONS: Euryale ferox is abundant in several macronutrients and micronutrients; and considered as a superfood in terms of various health benefits. E. ferox has the ability to be used in the development of different health, functional, and nutraceutical foods, which will open a new door for the food industry to combat with numerous diseases.

Processing, digestion property and structure characterization of slowly digestible gorgon nut starch

Slowly digestible gorgon nut starch (GN-SDS) was prepared by heating-cooling treatment (HCT), meanwhile its morphological and structural features were characterized in detail by SEM, DSC, XRD and IR detection. The optimized parameters of GN-SDS processing were as following: starch milk (20%) was heated at 100 °C for 20 min, and then cooled under 4 °C for 24 h. Under the optimized parameters, the SDS content increased from 20.49 to 61.74%. GN-SDS showed typical SDS characteristics in in vivo digestion with a low postprandial blood glucose. SEM images suggested that GN-S particles changed from uniform regular polyhedron with smooth surface to irregular gravel-like particles with coarse surface and obvious layered structure inside after HCT. The results of SEM, DSC, XRD and IR determination indicated that HCT changed the granule morphology, interior structure, gelatinization temperature and crystal type (A to B-type) of GN-S, and therefore made it hard to be digested accordingly.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10068-021-01007-6.

Cellular Anti-Melanogenic Effects of a Euryale ferox Seed Extract Ethyl Acetate Fraction via the Lysosomal Degradation Machinery

The aim of this study was to investigate the effect of ethyl acetate fraction of Euryale ferox seed extracts (Efse-EA) on melanogenesis in immortalized mouse melanocyte cell line, melan-a. Efse-EA showed strong dose-dependent mushroom tyrosinase inhibitory activity. Treatment of melan-a cells with 30 μg/mL Efse-EA produced strong inhibition of cellular tyrosinase and melanin synthesis. Efse-EA significantly reduced the levels of melanogenesis-related proteins, such as tyrosinase, tyrosinase-related proteins 1 and 2, and microphthalmia-associated transcription factor. Because Efse-EA treatment reduced tyrosinase protein levels without changing its mRNA expression, we investigated whether this decrease was related to proteasomal or lysosomal degradation of tyrosinase. We found that chloroquine, a lysosomal proteolysis inhibitor, almost completely abolished both the down-regulation of tyrosinase and the inhibition of melanin synthesis induced by Efse-EA. These results suggested that Efse-EA may contribute to the inhibition of melanogenesis by altering lysosomal degradation of tyrosinase, and that this extract may provide a new cosmetic skin-whitening agent.

Determination of the absolute configuration of natural products

Structural elucidation of natural products is always one of the most important tasks for natural product researchers in related fields. Particularly, the absolute configuration (AC), being a great challenge for natural product chemists, has attracted much attention. During the past few decades, many techniques and approaches have been developed to determine the AC of natural products, including direct (or absolute) methods, e.g. X-ray diffraction (XRD), electronic and vibrational circular dichroism (ECD and VCD), and Raman optical activity (ROA), as well as indirect (or relative) methods using a reference or a derivatizing agent with known AC, e.g. CD with empirical rules and nuclear magnetic resonance (NMR) utilizing anisotropic effects of chiral derivatizing agents. However, none of the currently applied techniques is capable of dominating AC determination, since they each have their respective limitations corresponding to the different structural features. This mini review summarizes most of the techniques and methods which are commonly used in AC assignment of natural products, or have potential application prospects, and briefly describes their principles, advantages and limitations.