With no explanation, label each line with "O", "other-biologything", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Proline
and
its
derivatives
are
often
used
as
asymmetric
catalysts
in
proline
organocatalysis
reactions
.
Proline:other-biologything
and:O
its:O
derivatives:O
are:O
often:O
used:O
as:O
asymmetric:other-biologything
catalysts:other-biologything
in:O
proline:other-biologything
organocatalysis:other-biologything
reactions:O
.:O