About: http://webisa.webdatacommons.org/289879141

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	It is preferred that Ra is an alkylene group and it is particularly preferred that the alkylene group is methylene.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com