About: http://webisa.webdatacommons.org/48612055

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	Ra and Rb are preferably, independently of one another, H or C1 -C4 alkyl, for example methyl or ethyl.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com