About: http://webisa.webdatacommons.org/82759389

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	R1, R2 =H, Alkyl, aryl, alkylcarbonyl, arylcarbonyl, alkyloxycarbonyl, aryloxycarbonyl, or a polymer such as PEG, PVA, or polyamino acid, attached directly or through a carbonyl group.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com