About: http://webisa.webdatacommons.org/450380194

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	R is a hydrogen, lower alkyl (preferably C1 -C5, more preferably C1 -C3), aryl or alkoxy
http://www.w3.org/ns/prov#wasQuotedFrom	google.com