| abstract |
The present invention provides a compound having high reactivity with a functional group such as an aldehyde group. The present invention has the general formula 1: in R 1 -NH-O-L 1 -D-L 2 -A (1) ( wherein, R 1 represents a hydrogen atom, a protecting group of an alkyl group or an amino group, D Is a divalent aromatic group, L 1 is a direct bond or a linker group, L 2 is a direct bond or a linker group, and A is an organic group containing a hydrophilic group). Or a salt thereof. |