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What is the molecular formula of the molecule identified by 3-[(1R,3S,3aR,6aR)-5-butyl-6',7'-dimethyl-2',4,6-trioxospiro[1,2,3a,6a-tetrahydropyrrolo[3,4-c]pyrrole-3,3'-1H-indole]-1-yl]propanoic acid ?
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C22H27N3O5
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