| Label | Id | |
|---|---|---|
| Xaa-Arg | 10051 | |
| Xaa-His | 10052 | |
| Xaa-Lys | 10053 | |
| Xaa-ornithine | 10054 | |
| Xamoterol | 10055 | |
| Xanthatin | 10058 | |
| Xanthinin | 10061 | |
| Xanthoxylin | 10070 | |
| Xanthumin | 10071 | |
| Xanthyletin | 10073 | |
| Xerantholide | 10076 | |
| Xylometazoline | 10082 | |
| Xylopine | 10083 | |
| Xylopinine | 10084 | |
| Yamogenin | 10086 |