Strychnos pseudoquina and Its Purified Compounds Present an Effective In Vitro Antileishmanial Activity
Table 1
Structural and chemical characterizations of the two flavonoids purified from S. pseudoquina. 1H and 13C chemical shifts (ppm) obtained for quercetin 3-O-methyl ether and strychnobiflavone.
Positions
Quercetin 3-O-methyl ether (δ H)a
Quercetin 3-O-methyl ether (δ H)c
Quercetin 3-O-methyl ether (δ C)a
Quercetin 3-O-methyl ether (δ C)c
Strychnobiflavone (δ H)b
Strychnobiflavone (δ H)d
Strychnobiflavone (δ C)b
Strychnobiflavone (δ C)d
2
—
—
158.5e
157.3
—
—
155.5
157.4
3
—
—
139.7
138.4
—
—
137.4
138.7
4
—
—
180.1
178.9
—
—
178.0
179.1
5
—
—
166.0
161.9
—
—
154.1
162.0
6
6.18; d (.0 Hz)
6.21
99.9
98.6
6.16; s
6.26; s
97.9
98.8
7
—
—
163.2
164.8
—
—
159.9
164.2
8
6.37; d (.0 Hz)
6.41
94.8
93.5
—
—
102.8
103.6
9
—
—
158.1e
156.8
—
—
161.2
155.5
10
—
—
106.0
104.7
—
—
104.0
105.5
1′
—
—
123.6
121.8
—
—
121.1
123.0
2′
7,61; d (.0 Hz)
7.64
116.5f
115.3
7.44; d ( Hz)
7.60; d ( Hz)
115.9
124.0
3′
—
—
146.6
145.3
—
—
145.1
148.7
4′
—
—
150.1
148.8
—
—
148.6
145.3
5′
6,89; d (.4 Hz)
6.92
116.6f
115.2
6.71; d ( Hz)
6.82; d ( Hz)
115.4
115.7
6′
7,51; dd (.4 Hz; 2.0 Hz)
7.55
122.5
121.2
7.05; dd ( Hz; 2.0 Hz)
7.29; dd ( Hz; 2 Hz)
120.2
121.7
2′′
—
—
—
—
—
—
159.1
157.4
3′′
—
—
—
—
—
—
138.2
138.7
4′′
—
—
—
—
—
—
177.8
179.0
5′′
—
—
—
—
—
—
156.3
161.9
6′′
—
—
—
—
6.07; d ( Hz)
6.10 ( Hz)
98.4
98.9
7′′
—
—
—
—
—
—
163.9
162.5
8′′
—
—
—
—
5.66; d ( Hz)
5.84; d ( Hz)
92.8
93.6
9′′
—
—
—
—
—
—
161.2
156.4
10′′
—
—
—
—
—
—
104.2
105.5
1′′′
—
—
—
—
—
—
122.3
122.9
2′′′
—
—
—
—
—
—
119.7
116.2
3′′′
—
—
—
—
—
—
144.2
147.9
4′′′
—
—
—
—
—
—
147.5
148.8
5′′′
—
—
—
—
6.97; d ( Hz)
7-7.1; m
114.1
114.9
6′′′
—
—
—
—
7.05; d ( Hz)
7-7.1; m
121.4
119.8
3-O-Me
3.77; s
3.80
60.6
59.35
3.79; s
3.82; s
59.8
60.3
3′′-O-Me
—
—
—
—
3.43; s
3.63; s
59.6
59.9
5-OH
12.47; s
—
—
—
12.68; s
12.8; s
—
—
5′′-OH
—
—
—
—
12.56; s
12.6; s
—
—
CD3OD; bDMSO-d 6; cDMSO-d 6 (Guinot et al. 2009 [22]); dacetone-d 6 (Nicoletti et al. 1984 [20]); e,finterchangeable.