Electrospray tandem mass spectrometric analysis of a dimeric conjugate, salvialeriafone and related compounds

BMC Chemistry

Table 2 Negative ionization HR-ESI-MS data and common neutral losses of diterpenoids 1–6

S.No.	[M-H]^-	Exact Mass	Observed mass	Error (ppm)	[M+H-H₂O]^-	[M+H-CO]^-	[M+H-CH₄]^-	[M+H-CH₃]^-	[M+H- C₃H₇]^-.	[M+H-C₃H₇- CO]^-.	[M+H- H₂O-CO]^-	[M+H-CH₄-CO]^-	Base Peak
1	C₃₉H₄₉O₇⁺	627.3327	627.3372	7.1286	-	-	-	-	584	556	538 [M+H-C₃H₇- CO-H₂O]^-.	-	584 [M+H-C₃H₇]^-.
2	C₂₀H₂₇O₃⁺	313.1809	313.1789	−6.4452	-	285	297	298	-	-	-	269	285 [M+H-CO]^-
3	C₂₀H₂₇O₅⁺	345.1707	345.1694	−3.9046	327	317	-	-	-	-	299	-	317 [M+H-CO]^-
4	C₂₁H₃₁O₄⁺	345.2071	345.2075	1.0622	315 [M+H-CH₂O]^-	-	-	330	-	-	287 [M+H-CH₂O-CO]^-	-
5	C₂₀H₂₇O₅⁺	345.1707	345.1698	−2.7458	327	317	-	-	-	-	-	-	179
6	C₁₉H₂₃O₃⁺	297.1496	297.1512	5.3227	-	269	281	282	-	-	-	253	269 [M+H-CO]^-

ISSN: 2661-801X