In this task, you are given a sentence. You are expected to recognize the name of any form of chemical substances. Although there might be several correct answers, you need to write one of them.

Q: Probing the Role of the Vancomycin E-Ring Aryl Chloride: Selective Divergent Synthesis and Evaluation of Alternatively Substituted E-Ring Analogues.

A: Vancomycin
****
Q: Identification and characterization of a novel flavin-containing spermine oxidase of mammalian cell origin.

A: spermine
****
Q: Comparative analysis of nutritional compositions of transgenic high iron rice with its non-transgenic counterpart.

A:
iron
****