1 VGL Pyrazine-2-carboxylic acid 1.000 2 NMJ 6-chloropyrazine-2-carboxylic acid 0.900 3 OJX 5-methyl-4-oxidanyl-pyrazin-4-ium-2-carboxylic acid 0.818 4 6PC Pyridine-2-carboxylic acid 0.800 5 CPI 6-carboxypiperidine 0.800 6 ID7 (3r)-piperidine-3-carboxylic acid 0.800 7 NIO Nicotinic acid 0.800 8 PZA Pyrazine-2-carboxamide 0.800 9 YCP (2s)-piperidine-2-carboxylic acid 0.800 10 1WD 3-sulfanylpyridine-2-carboxylic acid 0.727 11 3A0 (2s,4s)-4-methylpiperidine-2-carboxylic acid 0.727 12 53B 6-hydroxypyridine-2-carboxylic acid 0.727 13 5HN 5-hydroxypyridine-3-carboxylic acid 0.727 14 ES6 2-oxo-1,2-dihydropyridine-3-carboxylic acid 0.727 15 MHV 4-oxo-L-pipecolic acid 0.727 16 MHW 3-hydroxypicolinic acid 0.727 17 O9B (2~{R})-1-methylpiperidine-2-carboxylic acid 0.727 18 OA7 6-hydroxypyridine-3-carboxylic acid 0.727 19 Y31 5-bromopyridine-3-carboxylic acid 0.727 20 25R 2,5-dimethylpyrazine 0.700 21 2PC 3,4-dihydro-2h-pyrrolium-5-carboxylate 0.700 22 8LJ (2s)-2,3-dihydro-1h-pyrrole-2-carboxylic acid 0.700 23 DPR D-proline 0.700 24 PKN 1h-pyrrole-3-carboxylic acid 0.700 25 PRO Proline 0.700 26 PRS Thioproline 0.700 27 PYC Pyrrole-2-carboxylate 0.700 28 PYF 3-pyridinylcarbinol 0.700 29 T2C (2s)-1,3-thiazolidine-2-carboxylic acid 0.700