Um novo alcalóide benzofenantridínico, 6-acetonil-N-metil-diidrodecarina foi isolado das raízes de Zanthoxylum riedelianum juntamente com lupeol, 6-acetonildiidroqueleritrina e 6-acetonildiidroavicina. As estruturas dessas substâncias foram estabelecidas com base na análise dos dados espectrométricos de IV, EM e RMN incluindo experimentos 2D.A new benzophenanthridine alkaloid, 6-acetonyl-N-methyl-dihydrodecarine was isolated from Zanthoxylum riedelianum roots together with lupeol, 6-acetonyldihydrochelerythrine and 6-acetonyldihydroavicine. The structures were established from the IR, MS and NMR spectral data, including 2D-NMR experiments.
Keywords: Zanthoxylum riedelianum, Rutaceae, benzophenanthridine alkaloids
IntroductionThe Zanthoxylum genus (Rutaceae) is composed by more than 200 species and largely distributed around the world. 1 Chemically, this genus is characterized by alkaloids, 2-7 cumarins, 5,6,8 lignans, 4,9,10 amides 11,12 and terpenes. 5,6,13,14 Ongoing studies have shown that Zanthoxylum exhibit a range of biological activities such as antichagas, 2 tripanocidal, 9 antiplasmodial, 7 anti-HIV 13 and antiinflammatory, 8,10 as well as antihelmintic. 12 Z. riedelianum is used in folk medicine as a decoction against different types of inflammations, rheumatism and skin stains. 15 Previous works reported the identification of terpenes from the essential oil 14 and lignans from the leaves and the stem bark. 10 In this work we report the isolation and structural elucidation of a novel benzophenanthridine alkaloid, namely, 6-acetonyl-N-methyl-dihydrodecarine (1), together with two known alkaloids 6-acetonyldihydrochelerythrine (2) and 6-acetonyldihydroavicine (3) from the roots of Z. riedelianum.
Experimental
General proceduresMelting points were uncorrected. IR spectra were recorded on FTIR-Bomem-MB/100 model spectrophotometer using NaCl film. NMR spectra in CDCl 3 , were recorded on Bruker ARX-400 (400 MHz for 1 H and 100 MHz for 13 C); Bruker AC-200 (200 MHz for 1 H and 50 MHZ for 13 C) and Varian-Mercury 300 (300 MHz for 1 H and 75 MHz for 13 C) spectrometers, using tetramethylsilane (TMS) as internal standard. Electron Ionization Mass Spectra (ESI-MS) was undertaken employing a Quatro LC-Micromass UK model spectrometer. Optical rotations were determined on a Perkin-Elmer 341 polarimeter. CC: silica gel (Merck 70-230 mesh ASTM); TLC: silica gel G 60 and silica gel 60 PF 254 (Merck) were used to analyze the fractions collected from column chromatography (CC) with visualization by UV (254 and 366 nm), Dragendorff´s reagent and exposure to iodine vapor.
Plant materialZanthoxylum riedelianum (Engl.) was collected in Rio Manso Highway, km 22, Chapada dos Guimarães, Mato 6-Acetonyl-N-methyl-dihydrodecarine, a New Alkaloid from Zanthoxylum riedelianum J. Braz. Chem. Soc. 380 Grosso State, Brazil. A voucher specimen (No. 24.080) was deposited at Universidade Federal de Mato Grosso Central Herbarium.
Extraction and isolationDried roots (3.0 kg) were powdered and extracted with hexane and methanol by mac...