About: http://webisa.webdatacommons.org/182666632

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	R4 are hydrogen; X21 is --OH, --NH2, --OP, and --NHP, wherein P is a suitable protecting group; and q is 1 or 3. 2.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com