Two New Flavones from Salvia plebeia and Their Anti-Angiogenic Activities
- PDF / 164,347 Bytes
- 4 Pages / 594 x 792 pts Page_size
- 102 Downloads / 160 Views
TWO NEW FLAVONES FROM Salvia plebeia AND THEIR ANTI-ANGIOGENIC ACTIVITIES
Qinge Ma, Rongrui Wei,* Qixin Lu, Haofeng Huang, Dongmei Guo, and Lin Jiang
Two new flavones, namely 5-hydroxy-2-(4′-hydroxyphenyl)-6,12,13-trimethoxypyrano-xanthene-4,9-dione (1) and 5-hydroxy-2-(3′-methoxy-4′-hydroxyphenyl)-6-methoxy-11-isopropyl-pyranochromene-4,9-dione (2), were isolated from Salvia plebeia. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR spectral data. Compounds 1 and 2 were evaluated for their anti-angiogenic activities by the MTT assay with axitinib as positive control, and they displayed moderate anti-angiogenic activities with IC50 values of 14.07 and 11.25 μM, respectively. Keywords: Salvia plebeia, flavone, anti-angiogenic activity. Salvia plebeia (Lamiaceae) is used as a traditional medicinal plant for treating cough, hepatitis, diarrhea, gonorrhea, and hemorrhage in China [1]. Previous phytochemical investigations of S. plebeia revealed the presence of flavonoids [2], terpenoids [3], lignans [4], phenolics [5], essential oils [6], and aliphatic compounds [7] in this plant. S. plebeia has been reported to demonstrate pharmacological activities such as anti-inflammatory [8], anti-viral [9], antioxidant [10], antinociceptive [11], hepatoprotective [12], and inhibitory activity on NO production [13]. Although previous research has reported various biological activities of S. plebeia, the anti-angiogenic activity of flavones derived from S. plebeia has not been well studied. In a continuing effort to discover potential anti-angiogenic compounds from S. plebeia, we carried out a bioassay-guided investigation to study the anti-angiogenic constituents of S. plebeia [14]. As a result, two new flavones were obtained from S. plebeia. Compounds 1 and 2 were evaluated for anti-angiogenic activities by the MTT assay with axitinib as positive control. Herein, the details of the isolation, structural elucidation, and anti-angiogenic activities of compounds 1 and 2 are described. Compound 1 was isolated as a pale yellow powder; its molecular formula was assigned as C25H18O9 according to its HR-ESI-MS (m/z 463.1058 [M + H]+, calcd for C25H19O9, 463.1029) and NMR spectral data, indicating 17 degrees of unsaturation. In the 1H NMR spectrum of compound 1, the characteristic fragment of 4′-hydroxyphenyl at δ 10.23 (1H, br.s, 4′-OH), 7.96 (2H, d, J = 8.6 Hz, H-2′, 6′), 6.75 (2H, J = 8.6 Hz, H-3′, 5′) was connected to C-2 by the correlations of H-3 to C-1′ and H-2′, 6′ to C-2 in the HMBC spectrum (Fig. 1). Moreover, there were two singlets at δ 7.26 (1H, s, H-11) and 6.80 (1H, s, H-14) in the 1H NMR spectrum and δC 179.4 (C-9) in the 13C NMR spectrum (Table 1), which showed that compound 1 was an analogue of neocafhispidulin [15]. In the high field of 1H NMR spectrum of compound 1, there were two methoxy groups at δ 3.87 (3H, s, 12-OCH3) and 3.84 (3H, s, 13-OCH3) according to its HSQC spectra. The 12-OCH3 and 13-OCH3 groups were fused to C-12 and C-13 by the HMBC correlations of H-11 to 12-
Data Loading...
