Structures of mahanikbin and koenimbin

Efficient Construction of Pyrano[3,2‐a]carbazoles: Application to a Biomimetic Total Synthesis of Cyclized Monoterpenoid Pyrano[3,2‐a]carbazole Alkaloids

“…NMR spectra were recorded on Bruker DRX 500 and Avance III 600 NMR spectrometers. Complete assignment of the 1 H and 13 3-Methoxy-4-methyl-N-phenylaniline (16): 3-Methoxy-4-methylaniline (5.00 g, 36.4 mmol), palladium acetate (333 mg, 1.48 mmol), SPhos (1.20 g, 2.92 mmol), and cesium carbonate (13.4 g, 41.2 mmol) were dissolved in toluene (45 mL). After heating the suspension to 100 8C, a solution of iodobenzene (5.95 g, 29.2 mmol) in toluene (5 mL) was added dropwise over a period of 16 h. The mixture was stirred at 100 8C for additional 10 h. After a total of 26 h, the reaction mixture was cooled to room temperature, the solvent was removed under reduced pressure, and the residue was purified by chromatography on silica gel (petroleum ether/dichloromethane/ethyl acetate 60:5:1 to 45:5:1) to provide 16 (2): 3-Methoxy-4-methyl-N-phenylaniline (16) (2.05 g, 9.61 mmol), potassium carbonate (66.8 mg, 0.483 mmol), and pivalic acid (8.64 g) were placed in a 25 mL test tube.…”

“…M.p. 168-171 8C; UV (MeOH): l = 236, 260 (sh), 302, 332 nm; IR (ATR): ñ = 3390, 3028, 2920, 2853, 1630, 1606, 1497, 1458, 1385, 1339, 1304, 1228, 1209, 1176, 1151, 1140, 1106, 1026, 883, 815, 748, 724, 691 cm À1 ; 1 H NMR (500 MHz, CDCl 3 ): d = 2.43 (s, 3 H), 5.15 (s, 2 H), 6.89 (s, 1 H), 7.18 (m, 1 H), 7.29-7.35 (m, 3 H), 7.40 (t, J = 7.5 Hz, 2 H), 7.49 (d, J = 7.3 Hz, 2 H), 7.82 (s, 1 H), 7.85 (br s, 1 H), 7.95 ppm (d, J = 7.8 Hz, 1 H);13 C NMR and DEPT (125 MHz, CDCl 3 ): d = 16.90 (CH 3 ), 70.08 (CH 2 ), 93.90 (CH), 110.26 (CH), 116.44 (C), 119.29 (CH), 119.34 (CH), 119.65 (C), 121.58 (CH), 123.43 (C), 124.18 (CH), 127.06 (2 CH), 127.75 (CH), 128.54 (2 CH), 137.42 (C), 138.97 (C), 139.29 (C), 156.38 ppm (C); MS (EI): m/z (%): 287 (62) [M + ], 196 (100), 167 (18), 91 (20); HRMS: m/z calcd for C 20 H 17 NO [M + ]: 287.1310; found: 287.1292.2-Hydroxy-3-methyl-9H-carbazole (1) (Method A): A mixture of 2-benzyloxy-3-methyl-9H-carbazole (15) (324 mg, 1.12 mmol) and 10% Pd/C (50 wt %, 162 mg) in methanol/dichloromethane (30 mL, 4:1) was stirred at room temperature under a hydrogen atmosphere for 72 h. Subsequent flash chromatography on silica gel (petroleum ether/ethyl acetate, 2:1) afforded 2-hydroxy-3-methyl-9H-carbazole (1) (220 mg, 100 %) as a colorless solid; spectroscopic data, see below.…”

A benzoisofuranone derivative and carbazole alkaloids from Murraya koenigii and their antimicrobial activity

“…Traditionally, the plant is used as a stimulant, stomachic, febrifuge, analgesic and for the treatment of diarrhoea, dysentery and insect bites (Kirtikar et al, 1993;Yusuf et al, 1994). Previous phytochemical investigations on this plant revealed the occurrence of carbazole alkaloids (Narasimhan et al, 1968;Chowdhury and Chakraborty, 1971;Chakraborty et al, 1978;Rao et al, 1980;Bhattacharyya et al, 1982;Roy et al, 1982;Fiebig et al, 1985;Bhattacharyya and Chowdhury, 1985;Ito et al, 1993;Reisch et al, 1994;Saha and Chowdhury, 1998;Nutan et al, 1999;Ramsewak et al, 1999;Tachibana et al, 2001;Knolker and Reddy, 2002) and coumarins (Adebajo and Reisch, 2000;Murray et al, 1982). As a part of our research project focussing on Bangladeshi rutaceous species, we here report the isolation of a new benzoisofuranone derivative (10) and a new dimeric carbazole alkaloid (11) together with six known carbazoles and three known steroids from the stem bark of M. koenigii as well as the antimicrobial activities of compounds 1-3 and 6-11.…”

Antinociceptive activity of acute and chronic administration of Murraya koenigii L. leaves in experimental animal models

“…[5] Methanolic extract of Murraya koenigii leaves possess antinociceptive and anti-inflammatory activity. [6] The plant is reported to contain carbazole alkaloids[7] having antioxidant,[8–10] anti-inflammatory, and anti-tumor activities. [4] No research on analgesic activity has been carried out.…”