Bioguided Isolation and Structure Identification of Acetylcholinesterase Enzyme Inhibitors from Drynariae Rhizome

Table 2

¹³C-NMR data (500 MHz, CD₃OD) of the eight flavonoids (ppm).

Position	Naringenin	Eriodictyol	Kaempferol	Luteolin	Astragalin	Luteolin-7-O-β-D-glucoside	Naringin	Neoeriocitrin
1
2	79.1	78.·	146.4	164.3	156.8	164.5	80.5	79.3
3	42.6	41.9	135.7	102.9	133.2	103.0	44.0	42.9
4	196.3	196.0	175.9	181.7	177.2	181.8	198.3	197.2
5	164.3	163.4	160.7	157.6	161.2	161.1	165.5	163.6
6	95.8	94.9	98.2	99.2	99.6	99.5	96.5	96.4
7	166.4	166.6	163.7	164.5	165.6	162.9	166.4	165.2
8	95.1	95.7	93.5	94.0	93.9	94.7	95.3	95.4
9	163.5	162.4	156.0	161.5	156.1	156.9	164.4	163.2
10	102.3	101.8	103.1	103.7	103.5	105.3	104.7	103.5
1′	129.9	129.4	121.7	121.5	120.1	120.9	130.6	130.1
2′	128.1	114.3	129.5	113.9	130.1	113.3	128.9	113.4
3′	115.0	145.7	115.1	146.3	115.2	145.9	116.1	145.1
4′	157.6	145.0	159.2	149.9	160.4	150.5	158.9	145.6
5′	115.3	115.3	115.1	116.1	115.8	115.9	116.1	114.8
6′	128.1	117.9	129.6	119.2	130.3	119.2	128.9	118.0
1″	—	—	—	—	—	99.9	—	—
2″	—	—	—	—	—	73.1	—	—
3″	—	—	—	—	—	76.4	—	—
4″	—	—	—	—	—	70.8	—	—
5″	—	—	—	—	—	82.0	—	—
6″	—	—	—	—	—	60.6	—	—
Glc-1	—	—	—	—	101.1	—	102.4	101.2
Glc-2	—	—	—	—	74.3	—	79.0	77.8
Glc-3	—	—	—	—	77.5	—	78.8	77.6
Glc-4	—	—	—	—	69.9	—	71.0	70.8
Glc-5	—	—	—	—	76.5	—	77.9	76.7
Glc-6	—	—	—	—	60.9	—	62.0	60.9
Rha-1	—	—	—	—	—	—	99.1	98.0
Rha-2	—	—	—	—	—	—	72.0	70.8
Rha-3	—	—	—	—	—	—	72.0	69.8
Rha-4	—	—	—	—	—	—	73.7	72.5
Rha-5	—	—	—	—	—	—	69.8	68.6
Rha-6	—	—	—	—	—	—	18.0	16.9