O extrato bruto (DCM:MeOH 2:1) das raízes de Piper crassinervium foi submetido a fracionamentos cromatográficos resultando no isolamento e identificação de oito substâncias, sendo estas uma flavanona (5,4\'-diidroxi-7-metoxiflavanona [isosakuranetina]), duas hidroquinonas preniladas (1,4-diidroxi-2-[3\',7\'-dimetil-1\'-oxo-2\'-E-6\'-octadienil]-benzeno e 1,4-diidroxi-2-[3\',7\'-dimetil-1\'-oxo-2\'-Z-6\'-octadienil]-benzeno), um cromeno (ácido-2-metil-2-[4\'-metil-3\'-pentenil]2H-1-benzopirano-6-carboxílico), um derivado prenilado do ácido benzóico (ácido 4-hidroxi-3-[3\',7\'-dimetil-1\'-oxo-octa-2\'-E-6\'-dienil]-benzóico), uma amida isobutílica (piperlonguminina) e duas amidas piperidínicas (piperina e diidropiperina). As substâncias isoladas tiveram suas estruturas químicas determinadas por experimentos de espectrometria de massas, RMN de 1H e 13C e comparadas com os dados da literatura. / The crude extracts of the roots of Piper crassinervium was submitted to chromatographic steps yielding eight compounds including a flavanone (5,4\'-dihydroxy-7-methoxyflavanone [isosakuranetin]), two prenylated hydroquinones (1,4-dihydroxy-2-[3\',7\'-dimethyl-1\'-oxo-2\'-E-6\'-octadienyl]-benzene and 1,4-dihydroxy-2-[3\',7\'-dimethyl-1\'-oxo-2\'-Z-6\'-octadienyl]-benzene), one chromene (2-methyl-2-[4\'-methyl-3\'-pentenyl]-2H-1-benzopyran-6-carboxylic acid), one prenylated derivative of benzoic acid (4-hydroxy-3-[3\',7\'-dimethil-1\'-oxo]2\'-E-6\'-octadienyl-benzoic acid), one isobutyl amide (piperlonguminine) and two piperidine amides (piperine and dihydropiperine). The structures of the isolated compounds were determined by mass spectrometry, 1H and 13C NMR data by comparison with the literature data.

O extrato bruto (DCM:MeOH 2:1) das raízes de Piper crassinervium foi submetido a fracionamentos cromatográficos resultando no isolamento e identificação de oito substâncias, sendo estas uma flavanona (5,4\'-diidroxi-7-metoxiflavanona [isosakuranetina]), duas hidroquinonas preniladas (1,4-diidroxi-2-[3\',7\'-dimetil-1\'-oxo-2\'-E-6\'-octadienil]-benzeno e 1,4-diidroxi-2-[3\',7\'-dimetil-1\'-oxo-2\'-Z-6\'-octadienil]-benzeno), um cromeno (ácido-2-metil-2-[4\'-metil-3\'-pentenil]2H-1-benzopirano-6-carboxílico), um derivado prenilado do ácido benzóico (ácido 4-hidroxi-3-[3\',7\'-dimetil-1\'-oxo-octa-2\'-E-6\'-dienil]-benzóico), uma amida isobutílica (piperlonguminina) e duas amidas piperidínicas (piperina e diidropiperina). As substâncias isoladas tiveram suas estruturas químicas determinadas por experimentos de espectrometria de massas, RMN de 1H e 13C e comparadas com os dados da literatura. / The crude extracts of the roots of Piper crassinervium was submitted to chromatographic steps yielding eight compounds including a flavanone (5,4\'-dihydroxy-7-methoxyflavanone [isosakuranetin]), two prenylated hydroquinones (1,4-dihydroxy-2-[3\',7\'-dimethyl-1\'-oxo-2\'-E-6\'-octadienyl]-benzene and 1,4-dihydroxy-2-[3\',7\'-dimethyl-1\'-oxo-2\'-Z-6\'-octadienyl]-benzene), one chromene (2-methyl-2-[4\'-methyl-3\'-pentenyl]-2H-1-benzopyran-6-carboxylic acid), one prenylated derivative of benzoic acid (4-hydroxy-3-[3\',7\'-dimethil-1\'-oxo]2\'-E-6\'-octadienyl-benzoic acid), one isobutyl amide (piperlonguminine) and two piperidine amides (piperine and dihydropiperine). The structures of the isolated compounds were determined by mass spectrometry, 1H and 13C NMR data by comparison with the literature data.