Following the re-revised structure of bottromycin A2 (1), the main component of the bottromycin complex, two other components—bottromycins B2 (2) and C2 (3)—were reinvestigated. Their structures were elucidated using one- and two-dimensional NMR spectroscopy (1H, 13C, DEPT, 1H-1H COSY, HSQC, HMBC, ROESY) and mass spectrometry (MS), with reference to the established NMR assignments of 1. Acid hydrolysis revealed that 2 contains L-proline instead of 1's cis-3-methyl-L-proline, while 3 contains 3,3-dimethyl-L-proline. High-resolution FAB-MS determined the molecular formulas of 2 (C41H60N8O7S, molecular weight 808) and 3 (C43H64N8O7S, molecular weight 836), differing from 1 by one fewer CH2 unit (2) and one additional CH2 unit (3), respectively. NMR spectral comparisons showed that 2 lacks the methyl signal at δC 15.5 (C-8) of 1 and has a methylene carbon at C-7 (δC 32.9) instead of a methine carbon (δC 38.5), confirming L-proline. For 3, two methyl signals (δC 24.9, 28.3) and a quaternary carbon at C-7 (δC 43.4) confirmed 3,3-dimethyl-L-proline. Complete proton and carbon assignments for 2 and 3 were established via 2D NMR, and their amino acid sequences were verified by HMBC and ROESY correlations. Both 2 and 3 preserve the cyclic moiety linked to a linear chain, a structural feature shared with 1.