In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Nitrofurantoins were associated with anophthalmia or microphthalmos ( AOR = 3 . 7 ; 95 % CI , 1 . 1 - 12 . 2 ) , hypoplastic left heart syndrome ( AOR = 4 . 2 ; 95 % CI , 1 . 9 - 9 . 1 ) , atrial septal defects ( AOR = 1 . 9 ; 95 % CI , 1 . 1 - 3 . 4 ) , and cleft lip with cleft palate ( AOR = 2 . 1 ; 95 % CI , 1 . 2 - 3 . 9 ) .
### Output Text:
<span class="chemical">Nitrofurantoins</span> were associated with anophthalmia or microphthalmos ( AOR = 3 . 7 ; 95 % CI , 1 . 1 - 12 . 2 ) , hypoplastic left heart syndrome ( AOR = 4 . 2 ; 95 % CI , 1 . 9 - 9 . 1 ) , atrial septal defects ( AOR = 1 . 9 ; 95 % CI , 1 . 1 - 3 . 4 ) , and cleft lip with cleft palate ( AOR = 2 . 1 ; 95 % CI , 1 . 2 - 3 . 9 ) . 