. 2021 Mar 16;9:633870. doi: 10.3389/fchem.2021.633870

TABLE 1.

Summary of the serratamolide homologues, prodigiosin and serratiochelin A detected in the crude extracts obtained from S. marcescens P1 and NP1 that were identified using UPLC-MS^E analysis.

Crude extract	UPLC Rt (min)	Compound no	Proposed compound identity	Proposed fatty acid chain lengths	^d Molecular formula	m/z [M + H]⁺	^a Experimental M _r	^b Theoretical M _r	^c Mass error (∆_ppm)	Major UPLC-MS^E fragments
P1, NP1	3.76	1	Serranticin/Serratiochelin A	N/A	C₂₁H₂₃N₃O₇	430.1609	429.1530	429.1536	1.49	137, 192, 194, 211, 220, 250, 277, 294
P1	8.48	2	Prodigiosin	N/A	C₂₀H₂₅N₃O	324.2073	323.1994	323.1998	1.36	252, 266, 292, 309
P1, NP1	11.20	3	Open-ring serratamolide B	C₁₀ + C_12:1	C₂₈H₅₀N₂O₉	559.3600	558.3522	558.3516	-1.03	258, 266, 276, 284, 302, 541
P1, NP1	11.28	6	Open-ring serratamolide C	C₁₀ + C₁₂	C₂₈H₅₂N₂O₉	561.3749	560.3671	560.3673	0.89	212, 240, 258, 268, 276, 286, 304, 543
P1, NP1	11.49	4	Serratamolide A/Serrawettin W1	C₁₀ + C₁₀	C₂₆H₄₆N₂O₈	515.3331	514.3252	514.3254	0.47	212, 240, 258, 276, 469, 487, 497
NP1	12.46	8	^e Open-ring serratamolide 585	C_12:1 + C_12:1	C₃₀H₅₂N₂O₉	585.3738	584.3660	584.3673	2.26	238, 266, 284, 302, 567
P1, NP1	12.77	9	Serratamolide B	C₁₀ + C_12:1	C₂₈H₄₈N₂O₈	541.3485	540.3404	540.3411	0.55	212, 240, 258, 266, 276, 284, 302, 513, 523
P1, NP1	13.06	13	Serratamolide C	C₁₀ + C₁₂	C₂₈H₅₀N₂O₈	543.3644	542.3565	542.3567	0.44	212, 240, 258, 268, 276, 286, 304, 515, 525
NP1	13.76	11	Open-ring serratamolide 587	C₁₂ + C_12:1	C₃₀H₅₄N₂O₉	587.3908	586.3830	586.3829	-0.13	266, 268, 284, 286, 302, 304, 569
P1, NP1	14.02	18	Serratamolide 571	C₁₂ + C₁₂	C₃₀H₅₄N₂O₈	571.3931	570.3852	570.3880	4.98	222, 240, 268, 286, 304, 525, 553

^{^a}

Experimental monoisotopic M _r of compound was calculated using the Time-of-Flight (TOF) transform function in the MassLynx 4.1 software package.

^{^b}

Theoretical monoisotopic M _r of compound was calculated using ChemDraw Ultra 12.0 software package.

^{^c}

Mass error in ppm = $(\frac{Theoretical M_{r} - Experimental M_{r}}{Theoretical M_{r}}) \times 10^{6}$

^{^d}

Theoretical molecular formula of compound was calculated using ChemDraw Ultra 12.0 software package and experimental molecular formula was confirmed using the MassLynx 4.1 software package.

^{^e}

Novel serratamolide homologue.

N/A, not applicable.

Bold entries correspond to compound numbers.