TABLE 1

MS fragments and their interpretation of buspirone metabolites in human liver microsomes A similar MS/MS fragmentation pattern of buspirone under ionspray ionization conditions was previously reported (Kerns et al., 1997).

Compound	Identity	Retention Time	MH⁺	Fragment ions^a
Compound	Identity	Retention Time	MH⁺					A	B	C	D	E	F	G	H	Others^b
		min
Parent drug	Buspirone (Bu)	27.9	386	168	219	180	222	148/150	265	122	291	109, 140, 198, 344
M1	5-OH-1-PP	5.5	181					166		138
M2	1-PP	7.2	165					148		122		80, 95
M3	3′-OH-Bu	18.7	402	184			238	148/150	281	122	307	165, 178
M4	Oxa-Bu	22.6	402		219		238	148/150	281	122	307	98, 139
M5	5,6′-di-OH-Bu	22.8	418	184		196	238	164/166	281	138	307	98, 139
M6	6′-OH-Bu	24.0	402	184		196	238	148/150	281	122	307	139
M7	5-OH-Bu	26.6	402	168	235	180	222	164/166	265	138		109, 152
M8	Bu N-oxide	29.3	402	168		180	222	148/150	265	122		108, 136, 140, 152, 162, 177, 251, 277, 290, 384

↵ a Daughter ion spectra of protonated molecular ions were obtained with a Finnigan TSQ quantum mass spectrometer (see Materials and Methods)
↵ b Relative abundance of these fragments was greater than 5%