COc1ccc(-c2oc3cc(O)c(OC)c(O)c3c(=O)c2OC2OC(CO)C(O)C(O)C2O)cc1
The donor in a hydrogen bond is usually a strongly electronegative atom such as N, O, or F that is covalently bonded to a hydrogen bond. How many hydrogen bond donors does the molecule have?