O estudo químico dos frutos de Cipadessa fruticosa (Meliaceae) permitiu o isolamento dos limonóides cipadesina B (inédito) e swietemahonolídeo. Das raízes de Cedrela fissilis (Meliaceae) foi isolado o limonóide 3β-acetoxicarapina, inédito como produto natural, juntamente com os triterpenos ácido oleanólico e ácido oleanônico. Estes compostos, e outros seis mexicanolídeos anteriormente isolados de C. fruticosa, apresentaram atividade inseticida para as formigas cortadeiras Atta sexdens rubropilosa.The chemical investigation of the fruits of Cipadessa fruticosa (Meliaceae) afforded the new limonoid cipadesin B and the known swietemahonolide. From the roots of Cedrela fissilis (Meliaceae) were isolated the limonoid 3β-acetoxycarapin, new as natural product, along with the triterpenes oleanolic and oleanonic acid. These compounds and other six mexicanolide limonoids previously isolated from C. fruticosa showed insecticidal activity against the leafcutting ants Atta sexdens rubropilosa.
Keywords: Cedrela fissilis, Cipadessa fruticosa, limonoids, triterpenes, insecticidal activity
IntroductionCipadessa fruticosa Blume (Meliaceae) is widely cultivated in the southwest of China. This plant has been reported to contain ent-clerodanes and labdanes diterpenoids, 1,2 limonoids, sterols, sesquiterpenoids, heneicosene derivatives and one coumarin. 3,4 We have recently reported the isolation of six mexicanolide limonoids from this plant. 5 Cedrela fissilis Vell. (Meliaceae) is a valuable tree of timber industry. In Brazil, it can be found from Amazon forest up to north of Espírito Santo State. Previous investigation of fruits and seeds from this species afforded the limonoids fissinolide, mexicanolide and 3β-hydroxyisomexicanolide. 6 In a recent investigation we have isolated several gedunin limonoids from C. fissilis. 7 Extracts and fractions from C. fruticosa and C. fissilis have been shown activity on leaf-cutting workers Atta sexdens rubropilosa. 8,9 Thus, the aim of this work was the chemical investigation of these Meliaceae species associated with biological assays against Atta sexdens rubropilosa. The study of the fruits of C. fruticosa allowed the isolation of a new mexicanolide limonoid: cipadesin B (1) and the known swietemahonolide (2). The limonoid 3β-acetoxycarapin (3) isolated from fruits of C. fissilis, is new as natural product and its spectral data are being described for the first time. The triterpenes oleanolic acid (4) and oleanonic acid (5) were also isolated from C. fissilis. The evaluation of the activity on leaf-cutting ants of these compounds, along with the following mexicanolide limonoids previously isolated from C. fruticosa: cipadesin A (6), ruageanin A (7), cipadesin (8), khayasin T (9), febrifugin (10) and mexicanolide (11)
Extraction and isolation of compoundsThe powdered air-dried fruits (990 g) of C. fruticosa were subsequently extracted with hexane, CH 2 Cl 2 and MeOH. The concentrated CH 2 Cl 2 extract (10.9 g) was submitted to vacuum chromatography over silica gel using a hexane-CH 2 Cl 2 ...