1 4TB 4-(2-thienyl)butyric acid 1.000 2 Y8G 2-butylthiophene 0.818 3 CLT 4-phenyl-butanoic acid 0.769 4 SNR Norbiotin 0.733 5 3FB (3s)-3-amino-4-phenylbutanoic acid 0.714 6 HMF 2-amino-4-phenyl-butyric acid 0.714 7 HPE Homophenylalanine 0.714 8 Y9E 2-oxo-4-phenylbutanoic acid 0.714