In Vitro Antidiabetic Effects of Isolated Triterpene Glycoside Fraction from Gymnema sylvestre

Table 2

¹³C NMR spectral data for gymnemagenin and respective gymnemic acids (δ in DMSO-d₆).

Position	Gymnemagenin ()	Gymnemic acid I ()	Gymnemic acid IV ()	Gymnemic acid VII ()
C-1	38.6	++	++	38.6
C-2	27.2	26.8	26.8	27.2
C-3	70.6	77.3	76.5	76.5
C-4	42.3	42.9	42.3	42.3
C-5	49.1	- -	- -	49.1
C-6	17.7	17.6	17.6	17.7
C-7	32.2	- -	- -	32.2
C-8	40.2	++	++	40.2
C-9	46.7	46.6	46.6	46.7
C-10	36.2	++	++	36.2
C-11	24.9	24.5	23.6	24.9
C-12	121.5	124.8	122.2	121.5
C-13	141.8	- -	- -	141.8
C-14	41.9	- -	- -	41.9
C-15	34.2	35.6	35.6	34.2
C-16	67.3	- -	- -	67.3
C-17	46.0	46.0	46.4	46.0
C-18	42.0	- -	- -	42.0
C-19	46.4	- -	- -	46.4
C-20	34.2	36.0	36.0	34.2
C-21	77.0	78.4	78.4	77.0
C-22	73.7	72.5	72.5	73.7
C-23	70.6	62.3	62.3	70.6
C-24	13.4	14.6	14.4	13.4
C-25	16.2	16.3	16.3	16.2
C-26	17.0	17.1	17.1	17.0
C-27	27.2	27.3	27.3	27.2
C-28	60.0	63.0	60.0	60.0
C-29	31.8	29.5	29.2	31.8
C-30	19.7	21.6	21.2	19.7
		Acetyl 1 - 172.6
		Acetyl 2 – 22.5
		Tigloyl 1’ - 170.9
		Tigloyl 2’ - 129.7
		Tigloyl 3’ - 139.1
		Tigloyl 4’ - 14 .4
		Tigloyl 5’ -12.6
		3-0--D-glucopyranosiduronic acid
		C1 - 103.9
		C2 - 74.0
		C3 - 76.6
		C4 - 72.4
		C5 - 75.2
		C6 - 175.9

++: overlapped signals; - -: not assigned.