Nc1ncnc2c1ncn2[C@@H]1O[C@H](CNCc2ccccc2OC2OC(CO)C(O)C(O)C2O)[C@@H](O)[C@H]1O
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?