Syringic acid can be found in several fruits including olives, dates, spices, pumpkin, grapes,[4] acai palm,[5] honey, red wine, among others.[2] Its presence in the ancient Egyptian drink shedeh could confirm it was made out of grape, as syringic acid is released by the breakdown of the compound malvidin, also found in red wine. It is also found in vinegar.[6]
^Pezzuto, John M. (August 2008). "Grapes and Human Health: A Perspective". Journal of Agricultural and Food Chemistry. 56 (16): 6777–6784. doi:10.1021/jf800898p. ISSN0021-8561. PMID18662007.
^Pacheco-Palencia LA, Mertens-Talcott S, Talcott ST (Jun 2008). "Chemical composition, antioxidant properties, and thermal stability of a phytochemical enriched oil from Acai (Euterpe oleracea Mart.)". J Agric Food Chem. 56 (12): 4631–4636. doi:10.1021/jf800161u. PMID18522407.
^Gálvez, Miguel Carrero; Barroso, Carmelo García; Pérez-Bustamante, Juan Antonio (1994). "Analysis of polyphenolic compounds of different vinegar samples". Zeitschrift für Lebensmittel-Untersuchung und -Forschung. 199: 29–31. doi:10.1007/BF01192948. S2CID91784893.
^Uyama, Hiroshi; Ikeda, Ryohei; Yaguchi, Shigeru; Kobayashi, Shiro (2001). "Enzymatic Polymerization of Natural Phenol Derivatives and Enzymatic Synthesis of Polyesters from Vinyl Esters". Polymers from Renewable Resources. ACS Symposium Series. Vol. 764. p. 113. doi:10.1021/bk-2000-0764.ch009. ISBN0-8412-3646-1.