New Lignans from Kadsura coccinea and Their Nitric Oxide Inhibitory Activities

Abstract

Kadsura coccinea (LEM.) A. C. SMITH is widely distributed throughout southwestern of China. Plant extracts have been used in Chinese folk medicine for treatment of cancer and dermatosis and as an anodyne to relieve aches in China. 2)Previous investigations of K. coccinea have yielded some lignans and triterpenoids. [3][4][5][6][7][8][9][10][11][12] However, little work on the isolation and characterization of anti-inflammatory constituents from this plant has been made. As a part of our continuing phytochemical investigation of anti-allergic agents from natural sources, 1) the chemical composition of the rhizoma of K. coccinea has been examined.The roots of K. coccinea were extracted with 80% acetone. The extract was then partitioned with hexane, chloroform, ethyl acetate, n-butanol and water, successively. The chloroform fractions showed strong NO production inhibitory activity. Further bioassay-directed fractionation of this fraction led to the isolation of two new dibenzocyclooctadiene lignans, kadsuralignan A (1), kadsuralignan B (2), and one new arylnaphthalene lignan kadsuralignan C (3), with three known dibenzocyclooctadiene lignans gomisin R (4), schizanrin F (5), and schizanrin H (6).To our knowledge, it's the first report about arylnaphthalene lignan was isolated from K. coccinea.Here, we describe the isolation, structure elucidation and biological evaluation of these compounds.The configuration of biphenyl groups in all isolated dibenzocyclooctadiene lignans was determined basing on their characteristic circular dichroism (CD) spectra. The CD spectra of 1, 2, 4-6 showed a positive Cotton effect around 215-225 nm and a negative Cotton effect around 230-255 nm, suggesting that these dibenzocyclooctadiene lignans possessed an S-biphenyl configuration as gomisin B. 13,14)Kadsuralignan A (1) was obtained as colorless needles and assigned to possess a molecular formula of C 22 H 26 O 7 by high resolution electron impact ionization MS (HR-EI-MS) ([M] ϩ , m/z 402.1679) with ten unsaturation. The UV spectrum of 1 possessed characteristic UV spectrum (l max 220, 255, 289sh nm) of dibenzocyclooctadiene lignans.15) It possessed a biphenyl moiety due to two aromatic protons at d 6.67 and 6.34 (each 1H, s, H-4 and H-11) and twelve carbon atoms at d 150. 6, 138.3, 148.5, 113.5, 133.7 and 121.1 (C-1, 2, 3, 4, 5, 16, respectively); d 138.2, 102.5, 148.7, 135.7, 141.1, 119.2 (C-10, 11, 12, 13, 14, 15, respectively). Moreover, one methylenedioxy moiety at d 5.97 (2H, s, CH 2 -19) and three methoxyl groups at d 3.63, 3.79 and 3.95 (each 3H, s) occurred, and predictably located them at the biphenyl rings. In the cyclooctadiene ring, two secondary methyl groups at d 0.93 (3H, d, Jϭ7.5 Hz) and 1.16 (3H, d, Jϭ6.9 Hz) were assigned to CH 3 -17 and CH 3 -18, respectively. Moreover, the signal of oxygenated methine at d 83.9, 4.61 (1H, d, Jϭ11.7 Hz, C-9 and H-9).The detailed analysis of 1 using 1 H-1 H COSY and HMQC disclosed partial structure unit with correlated protons: CH 2 -CH(CH 3 )-CH(CH 3 )-CH(OH), this unit should...

Dibenzocyclooctadiene Lignans from Schisandra lancifolia and Their Anti-human Immunodeficiency Virus-1 Activities

“…acetone extract prepared from the leaves and stems of S. lancifolia was partitioned between EtOAc and H 2 O. The EtOAc layer was subjected repeatedly to column chromatography on Si gel, Sephadex LH-20, RP-18 and preparative HPLC to afford compounds 1-16, including 3 new lignans named schilancifolignans A-C (1-3), together with 13 known, kadsuralignan A (4), 18) methylisogomisin O (5), 19) kadsuranin (6), 20) isogomisin O (7), 21) 12-demethylwuweilignan I (8), 22) angeloylisogomisin O (9), 21) schisandrin A (10), 23) gomisin N (11), 24) (ϩ)-gomisin K 2 (12), 25) gomisin J (13), 26) (ϩ)-schizandrin (14), 26) bznzoylgomisin Q (15), 27) angeloygomisin Q (16). 28) The structures of the compounds 1-16 were as shown in Fig.…”

“…3). 18) In addition, H-7 and H-8 were both correlated with H-9b, revealing the a-orientations of both Me-17 and Me-18. This was also supported by the ROESY correlations observed between Me-17 and Me-18, and between the Me-17 and the aromatic H-4.…”

Four New Dibenzocyclooctadiene Lignans from Schisandra rubriflora

“…The configurations of the biphenyl groups were determined based on their characteristic circular dichroism (CD) spectra. The CD spectra of 1, 3 and 4 showed positive Cotton effects around 222 -237 nm and a negative Cotton effect around 255 and 259 nm, while 2 showed two positive Cotton effects around 235 and 248 nm, suggesting that 1, 3 and 4 possessed (aS)-configuration, while 2 possessed an (aR)-configuration [15] [16].…”

Diastereoselective synthesis of β-piperonyl-γ-butyrolactones from morita-baylis-hillman adducts. highly efficient synthesis of (±)-yatein, (±)-podorhizol and (±)-epi-podorhizol

“…6,7 Kadsuralignan J (4) was isolated from roots of the chinese plant Kadsura coccinea and presents a moderate nitric oxide inhibitory activity. 8 Beilschmin A (5) was isolated from the stems of chinese plant Beilschmiedia tsangii. This lignan was found to exhibit significant in vitro cytotoxicity against P-388 and HT-29 cell lines, with IC 50 values of 1.2 and 5.0 mg mL -1 , respectively.…”