Characterization of Metabolites of Leonurine (SCM-198) in Rats after Oral Administration by Liquid Chromatography/Tandem Mass Spectrometry and NMR Spectrometry

Table 3

The ¹³C and ¹H NMR data for M1 and leonurine.

Number	Carbon signals^a,b		Proton signals^a,b
	Leonurine	M1	Leonurine	M1
1	157.3	159.2
2	40.9	43.2	3.15 (t, 2H, 𝐽=6.65 Hz)	3.04 (t, 2H, 𝐽=6.65 Hz)
3	26.4	27.1	1.73 (m, 2H)	1.62 (t, 2H, 𝐽=7.14 Hz)
4	26.8	27.5	1.58 (m, 2H)	1.52 (quintet, 2H, 𝐽=6.96 Hz)
5	63.8	68.1	4.26 (t, 2H, 𝐽=6.16 Hz)	4.11 (t, 2H, 𝐽=6.06 Hz)
6	166.6	170.1
7	124.6	128.6
8 and 12	105.4	109.6	7.22 (s, 2H)	7.05 (s, 2H)
9 and 11	147.8	154.6
10	138.9	140.0
13 and 14	56.6	58.7	3.82 (s, 6H)	3.68 (s, 6H)
1^′c		104.7		4.99 (d, 1H, 𝐽=7.44 Hz)
2′		75.9		3.36–3.45 (m, 1H)
3′		79.2		3.48 (t, 1H, 𝐽=4.50 Hz)
4′		74.2		3.36–3.45 (m, 1H)
5′		78.0		3.36–3.45 (m, 1H)
6′		177.5

aAll spectra were recorded on a Bruker Avance 400 spectrometer, in D₂O.
^bThe carbon and proton signals were assigned on ¹H NMR, ¹³C NMR, HMBC, and HSQC.
^cCarbon number of glucuronic acid moiety.