COc1c2c(nc3ccccc13)-c1cc(C(CC(=O)OC(C)(C)C)C(=O)OC(C)C)c(CO)c(=O)n1C2
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?