COc1c(O)c2c(=O)cc(OC)c3c4c(OC)cc(O)c5c(=O)c(OC)c6c(c(c1[C@H](C(C)=O)[C@](C)(O)C6)c23)c54
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?