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Preclinical Antidepressant-Like Effects of Terpenes, Polyphenolics, and Other Non-Flavonoid Phytochemicals
Published in Scott Mendelson, Herbal Treatment of Major Depression, 2019
Aside from simple reduction of reactive oxygen specifies, some non-flavonoid phytochemicals – like some flavonoids – can act as ligands within the intracellular cascades controlling responses to oxidative stress and inflammation.3 Examples are resveratrol,4 a stilbene, and ellagic acid,5 a dilactone of the biphenolic compound, hexahydroxydiphenic acid. Although structurally distinct from flavonoids and each other, both can directly inhibit the NLRP3 inflammasome.
Plant Phenolics
Published in Ruth G. Alscher, John L. Hess, Antioxidants in Higher Plants, 2017
The next level of structural complexity in the "hydrolysable tannins" resides with the ellagitannins, e.g., hexahydroxydiphenic acid 15 (Type B, Figure 2), that are formed via 2,2′-coupling of galloyl 1 residues; this coupling is considered to occur only after attachment of the galloyl moieties to the glucose core. During isolation, hexahydroxydiphenic acid 15 spontaneously cyclizes to give the corresponding dilactone, ellagic acid 16, and hence, these polyphenols are normally referred to as ellagitannins. Surprisingly, the enzyme catalyzing the (presumed) specific coupling of galloyl residues to give the ellagitannins has not been reported. Lastly, depending upon the species, the hexahydroxydiphenic components of the ellagitannins can undergo subsequent transformations involving aromatic ring fission following oxidative or reductive processes;16 however, the biochemistry of such processes has not been investigated to date.
Chemistry of Syzygium cumini
Published in K. N. Nair, The Genus Syzygium, 2017
Gallic acid and ellagic acid are the building blocks of many tannin materials (gallotannins and elligatannins). An ethyl acetate solution of hydrolyzed alcoholic extract yielded gallic acid (209) and ellagic acid (210) from stem bark (Bhargava et al. 1974). Ellagic acid was also tentatively identified from flowers by color reactions and formation of the tetraacetate (Nair and Subramanian 1962). Many other derivatives of gallic and ellagic acid have been isolated, including hexahydroxydiphenic acid (211) (Bhatia et al. 1971), 3,3,4′-tri-O-methylellagic acid (212), 3,4′-di-O-methylellagic acid (213) (Bhatia and Bajaj 1975), dimethyl-4,4′-oxybis (3,5-dihydroxy benzoate) (214), and 4,4′-oxybis(3,5-dihydroxy benzoic acid) (215). Compounds 214 and 215 produced irreversible antihyperglycemic efficacy in prolonged therapeutic application and also restored normal body weight and the lipid profile in an animal model, and have been patented as safe and effective antidiabetic therapeutic agents (Ghosh et al. 2008). Moreover, seeds yielded valoneic acid dilactone (216), brevifolin carboxylic acid (217), ellagic acid (210), gallic acid (209) (Mahmoud et al. 2001; Omar et al. 2012), and bergenin (218) from bark (Kopanski and Schnelle 1988).
Phenolic extract of Eugenia uniflora L. and furanone reduce biofilm formation by Serratia liquefaciens and increase its susceptibility to antimicrobials
Published in Biofouling, 2020
Adeline Conceição Rodrigues, Felipe Alves de Almeida, Cleriane André, Maria Cristina Dantas Vanetti, Uelinton Manoel Pinto, Neuza Mariko Aymoto Hassimotto, Érica Nascif Rufino Vieira, Nélio José de Andrade
Peak 2 was tentatively identified as sanguiin H10 (Mullen et al. 2003) and represents 87% of the ellagitannins of the phenolic extract of pitanga. This ellagitannin present a molecular ion at m/z 783, but appeared to be a doubly charged ion, giving a true molecular weight of 1568, and MS/MS (MS2) yielded an ion at m/z 301. Ellagitannins, also known as hydrolyzable tannins, are esters of hexahydroxydiphenic acid (HHDP) and a polyol, usually quinic acid or glucose (Smeriglio et al. 2017), that spontaneously undergoes lactonization to form ellagic acid (m/z 301) when hydrolyzed (Okuda and Ito 2011). According to Mullen et al. (2003), in negative mode, conjugates of quercetin and ellagic acid produce identical ion fragmentation at m/z 301. However, on MS2 analysis, the quercetin [M-H]- at m/z 301 fragmented to form characteristic ions at m/z 179 and 151 whereas the equivalent ellagic acid at m/z 301 ion yields ions at m/z 257 and 229. The ellagitannins are also soluble in water and have high molecular weights. According to Williner et al. (2003) and Landete (2011), this class of compounds has antioxidant activities, as well as antimutagenic, anticarcinogenic, anti-inflammatory, and prebiotic effects.
Clot activators and anticoagulant additives for blood collection. A critical review on behalf of COLABIOCLI WG-PRE-LATAM
Published in Critical Reviews in Clinical Laboratory Sciences, 2021
G. Lima-Oliveira, L. M. Brennan-Bourdon, B. Varela, M. E. Arredondo, E. Aranda, S. Flores, P. Ochoa
Formally known as hexahydroxydiphenic acid dilactone, ellagic acid is an organic compound that activates the contact phase of the intrinsic coagulation pathway. This occurs through the non-proteolytic activation of human F XII zymogen when ellagic acid in a fine microcrystalline dispersion is added to blood [54, 88].