nÃo hà / Este trabalho descreve o estudo fitoquÃmico das cascas e do lenho de Andira surinamensis (Leguminosae), bem como a composiÃÃo quÃmica volÃtil dos Ãleos essenciais das folhas e frutos de Piper divaricatum G. Mey (Piperaceae). O estudo fitoquÃmico dos extratos de A. surinamensis, utilizando tÃcnicas clÃssicas de cromatografia em gel de sÃlica, resultou no isolamento de um dÃmero isoflavona inÃdito na literatura, 4â-metoxiisoflavona-(7-O-7ââ)-3âââ,4âââ- metilenodioxiisoflavona (Surinamensina), um triterpeno pentacÃclico comumente conhecido como Lupeol e mais quatro isoflavonas: 5,7-dihidroxi-4â-metoxiisoflavona (biochanina A), 5,4â- dihidroxi-7-metoxiisoflavona (prunetina), 7,3â-dihidroxi-4â-metoxiisoflavona (calicosina) e 5,7,3â-trihidroxi-4â-metoxiisoflavona (pratenseÃna). A determinaÃÃo estrutural dos compostos isolados foram elucidadas por tÃcnicas espectroscÃpicas tais como: espectro de massa, espectro de infravermelho e RessonÃncia MagnÃtica Nuclear de 1H, 13C uni e bidimensionais. A composiÃÃo quÃmica dos Ãleos essenciais das folhas e frutos de Piper divaricatum G. Mey., foram analisadas por CG / EM e CG / DIC. Um total de 24 compostos, representando mais do que 94% da composiÃÃo quÃmica dos Ãleos, foram identificados. Ambos os Ãleos mostraram grande concentraÃÃes de monoterpenos, em especial, o Ãleo das folhas que apresentou 81,1%. Os Ãleos mostraram composiÃÃo quÃmica similares, mas o Ãleo dos frutos pode ser facilmente distinguido do Ãleo das folhas pela exclusiva presenÃa do a-felandrene (4,60%), (E)-muurola- 4(14),5-dieno (9,0%) e do (E)-cariofileno (11,4%). Os maiores constituintes do Ãleo das folhas foram: linalool (23,4%), b-pineno (25,3%) e a-pineno (18,8%), enquanto que os Ãleo frutos apresentaram b-pineno (18.0%), a-pineno (17.6%) e (E)-cariofileno (11.4%), como compostos majoritÃrios. / This work describes the phytochemical investigation of extracts from the branch wood and branch barks of Andira surinamensis (Leguminosae), as well as, the volatile chemical composition of essential oil from leaves and fruits of Piper divaricatum G. Mey (Piperaceae). The phytochemical investigation of A. surinamensis extracts, using classic methods of chromatography on silica gel, yielded a novel isoflavone dimer, 4â-methoxyisoflavone-(7-O- 7ââ)-3âââ,4âââ-methylenedioxyisoflavone (surinamensin), along with the triterpene lupeol and the known isoflavones 5,7-dihydroxy-4\\\'-methoxyisoflavone (biochanin A), 5,4\\\'-dihydroxy-7- methoxyisoflavone (prunetin), 7,3â-dihydroxy-4â-methoxyisoflavone (calycosin) and 5,7,3â- trihydroxy-4â-methoxyisoflavone (pratensein). The structures of all isolated compounds were elucidated by spectroscopic methods, such as MS, IR and particularly 1D and 2D homonuclear and heteronuclear NMR spectroscopy and, comparison with published data for closely related compounds. The chemical composition of the essential oils from leaves and fruits of Piper divaricatum G. Mey., was analyzed by GC/MS and GC-FID. Twenty-four components, representing more than 94.0% of the chemical compositions of the oils, were identified. Both oils showed higher concentrations of monoterpenoids, particularly the oils from leaves (81.1%). The oils showed some compositional similarities but the fruit oil could be easily distinguished from the leaf oil by the exclusive presence of a-phellandrene (4.60%), (E)-muurola-4(14),5-diene (9,0%) and significant content of (E)-caryophyllene (11.4%). The major constituents of the leaf oils were linalool (23.4%), b-pinene (25.3%) and a-pinene (18.8%), while the fruit oils of the fruits contained b-pinene (18.0%) and a-pinene (17.6%) and (E)-caryophyllene (11.4%) as prevalent compounds.