Table 2.

LC-MS analysis of metabolites involved in estrogen catabolism in N. tardaugens.

Compound name	LC-MS RT (min)	Molecular formula	Dominant ion peaks	Identified product ions
E2	18.39	C18H24O2	255.15	[M–H2O+H]+
E1	22.14	C18H22O2	271.19	[M+H]+
4-OHE1	17.06	C18H22O3	287.27	[M+H]+
Pyridinestrone acid	3.28	C18H21O3N	300.21	[M+H]+
4-Norestrogen-5(10)-en-3-oic acid (M5 deconjugated)	12.76	C17H22O4	273.32	[M–H2O+H]+
E3	5.55	C18H24O3	271.19	[M–H2O+H]+
16-keto-E2/16α-OH-E1	9.65	C18H22O3	287.31	[M+H]+
4-OH-16-keto-E2/4-OH-16α-OH-E1	5.79	C18H22O4	303.28	[M+H]+