About: http://webisa.webdatacommons.org/91328448

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	In the general formula (I???), R is a hydrogen atom or a methyl group, and preferably a hydrogen atom.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com