1.0 2026-09-22 17:04:20 UTC 2026-09-22 17:04:20 UTC FDB118566 Eckol 4-(3,5-dihydroxyphenoxy)dibenzo-p-dioxin-1,3,6,8-tetrol C18H12O9 372.285 372.048131966 4-(3,5-dihydroxyphenoxy)oxanthrene-1,3,6,8-tetrol eckol OC1=CC(OC2=C(O)C=C(O)C3=C2OC2=C(O)C=C(O)C=C2O3)=CC(O)=C1 InChI=1S/C18H12O9/c19-7-1-8(20)3-10(2-7)25-16-12(23)6-13(24)17-18(16)27-15-11(22)4-9(21)5-14(15)26-17/h1-6,19-24H PCZZRBGISTUIOA-UHFFFAOYSA-N belongs to the class of organic compounds known as tannins. These are naturally occurring polyphenols which be categorized into four main classes: hydrolyzable tannin (based on ellagic acid or gallic acid), condensed tannins (made of oligomeric or polymeric proanthocyanidins), complex tannins (made of a catechin bound to a gallotannin or elagitannin), and phlorotannins (oligomers of phloroglucinol). Tannins Organic compounds Phenylpropanoids and polyketides Tannins Aromatic heteropolycyclic compounds 1-hydroxy-2-unsubstituted benzenoids 1-hydroxy-4-unsubstituted benzenoids Diarylethers Dibenzo-p-dioxins Hydrocarbon derivatives Oxacyclic compounds Phenol ethers Phenoxy compounds Polyols Resorcinols 1-hydroxy-2-unsubstituted benzenoid 1-hydroxy-4-unsubstituted benzenoid Aromatic heteropolycyclic compound Benzenoid Diaryl ether Dibenzo-p-dioxin Ether Hydrocarbon derivative Monocyclic benzene moiety Organic oxygen compound Organoheterocyclic compound Organooxygen compound Oxacycle Phenol Phenol ether Phenoxy compound Polyol Resorcinol Tannin phlorotannin logp 2.71 ALOGPS logs -3.44 ALOGPS solubility 1.35e-01 g/l ALOGPS logp 2.68 ChemAxon pka_strongest_acidic 7.7 ChemAxon pka_strongest_basic -3.5 ChemAxon iupac 4-(3,5-dihydroxyphenoxy)oxanthrene-1,3,6,8-tetrol ChemAxon average_mass 372.285 ChemAxon mono_mass 372.048131966 ChemAxon smiles OC1=CC(OC2=C(O)C=C(O)C3=C2OC2=C(O)C=C(O)C=C2O3)=CC(O)=C1 ChemAxon formula C18H12O9 ChemAxon inchi InChI=1S/C18H12O9/c19-7-1-8(20)3-10(2-7)25-16-12(23)6-13(24)17-18(16)27-15-11(22)4-9(21)5-14(15)26-17/h1-6,19-24H ChemAxon inchikey PCZZRBGISTUIOA-UHFFFAOYSA-N ChemAxon polar_surface_area 149.07 ChemAxon refractivity 90.61 ChemAxon polarizability 34.38 ChemAxon rotatable_bond_count 2 ChemAxon acceptor_count 6 ChemAxon donor_count 6 ChemAxon physiological_charge 0 ChemAxon formal_charge 0 ChemAxon Specdb::MsMs 3431244 Specdb::MsMs 3431245 Specdb::MsMs 3431246 Specdb::MsMs 3431247 Specdb::MsMs 3431248 Specdb::MsMs 3431249 Specdb::CMs 112110 Specdb::CMs 125506 Specdb::CMs 876408 Specdb::CMs 876409 Specdb::CMs 876410 Specdb::CMs 876411 Specdb::CMs 876412 Specdb::CMs 876413 Specdb::CMs 876414 Specdb::CMs 876415 Specdb::CMs 876416 Specdb::CMs 876417 Specdb::CMs 876418 Specdb::CMs 876419 Specdb::CMs 876420 Specdb::CMs 876421 Specdb::CMs 876422 Specdb::CMs 876423 Specdb::CMs 876424 Specdb::CMs 876425 Specdb::CMs 876426 Specdb::CMs 876427 Specdb::CMs 876428 Specdb::CMs 876429 Specdb::CMs 876430