Structure Analysis and Study of Biological Activities of Condensed Tannins from Bruguiera gymnorhiza (L.) Lam and Their Effect on Fresh-Cut Lotus Roots

Abstract

Bruguiera gymnorhiza (L.) Lam is a mangrove plant that spread in many parts of the world. Though mangrove plant polyphenols have been reported to exhibit many biological activities, little is known about mangrove plant tannins. To explore the application value of tannins from B. gymnorhiza, analyses on the structure and biological activity of condensed tannins (CTs) from Bruguiera gymnorhiza (L.) Lam were carried out. The results from 13C nuclear magnetic resonance (13C-NMR) and reversed-phase, high-performance liquid chromatography (RP-HPLC) showed that the CTs were dominated by procyanidins, with a small quantity of prodelphinidins and propelargonidins; and that the monomeric constituents of B. gymnorhiza tannins were catechin/epicatechin, gallocatechin/epigallocatechin and afzelechin/epiafzelechin. The CTs were reversible and mixed competitive inhibitors of tyrosinase and the 50% inhibiting concentration (IC50) was estimated to be 123.90 ± 0.140 μg/mL. The antioxidant activities of CTs from B. gymnorhiza leaves were evaluated, the IC50 for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid diammonium salt) (ABTS) scavenging activities were 88.81 ± 0.135 and 105.03 ± 0.130 μg/mL, respectively, and the ferric ion reducing antioxidant power (FRAP) value was 1052.27 ± 4.17 mgAAE/g. In addition, the results from fresh-keeping assays on fresh-cut lotus root reveal that CTs from B. gymnorhiza had excellent effects on inhibiting the activities of polyphenol oxidase (PPO) and peroxidase (POD), protecting fresh-cut lotus root from the oxidation of total phenolics and malondialdehyde (MDA) content and slowing the increase in total phenol content (TPC) at 4 °C during the whole storage period. Therefore, CTs showed good effects against the browning of fresh-cut lotus root. Together, these results suggested that B. gymnorhiza CTs are promising antibrowning agents for fresh-cut fruits.

Acute Toxicity of Aqueous Extract from Bredemeyera floribunda Root Bark in an Animal Model

“…However, the mass of the EG pancreas was greater than the mass of the CG. According to Liu et al [ 53 ], saponins in some plant species can activate the pancreatic hypertrophic (PI3K/Akt) pathway, causing significant changes in this organ.…”

The Peanut Skin Procyanidins Attenuate DSS-Induced Ulcerative Colitis in C57BL/6 Mice

“…Peanut skin contains a variety of dietary polyphenols, especially procyanidins, which may be major active components of peanut skin [ 29 ] and are composed of flavan-3-alcohol structural units, and the monomers, mainly including catechin, epicatechin, catechin gallate, epicatechin gallate, and epicatechin gallate, etc. [ 52 ]. The procyanidins can be divided into type A and type B procyanidins according to the different positions of chemical bonds between monomers.…”

Chemical Constituents and Biological Activities of Bruguiera Genus and Its Endophytes: A Review

“…rhynchopetala. These meroterpenoids have been classified as shikimate-meroterpenoids of the tricycloalternarene type (149)(150)(151)(152) and polyketidemeroterpenoids (131)(132)(133)(134)(135)(136)(137)(138)(139)(140)(141)(142)(143)(144)(145)(146)(147)(148), which contain tetraketide moieties derived from 3,5-dimethylors ellinic acid (131-143) and 6-methylsalicylic acid (144), and hexaketide moiety (145)(146)(147)(148), respectively.…”

“…The antioxidant and polyphenolrich leaves of B. gymnorrhiza can exert hepatoprotective effects by ameliorating liver tissue injury [7]. Condensed tannins from B. gymnorrhiza possessed notable anti-tyrosinase and antioxidant capabilities, effectively inhibiting browning reactions in fresh-cut lotus roots [146]. Ethanol extract of B. sexangula leaves had antioxidant and melanin inhibition activities without skin irritation [145] [113].…”