(you can use Graphic editor; a term in CSDB Linear is normalized upon search)
?DXylp(structure ID 37212) has 2490 matches in CSDB
bDXylp(structure ID 37913) has 2288 matches in CSDB
xLLys(structure ID 37324) has 72 matches in CSDB
xLSer(structure ID 37666) has 123 matches in CSDB