A new pyranone, (S)-2-(4-hydroxyphenylethyl)-6-methyl-2,3-dihydro-4H-pyran-4-one, with unusual carbon skeleton, and three new aristolochic acid derivatives (7-O-methylaristolochic acid F, sodium 7-O-methylaristolochate F and sodium aristolochate F) were isolated from Aristolochia urupaensis (Aristolochiaceae) stems together with 31 known compounds. The structures of the compounds were determined by spectroscopic analyses, including Fourier transform infrared (FTIR) and 1D and 2D nuclear magnetic resonance (NMR) techniques, and high-resolution mass spectrometry (HRMS).

Maceration and supercritical fluid extraction were used to prepare extracts from parts of plants (Holostylis reniformis) collected in two different regions of Brazil. ¹H NMR, HPLC-DAD-ESI/MS, HPLC-DAD, GC-MS, and chemometric techniques were used to analyse lignans in the extracts and showed that yields of SFE-CO2 were less than or equal to those of hexane maceration extracts. These analyses, in conjunction with the concentrations of aliphatic hydrocarbons, fatty acids and their methyl and ethyl derivatives in the extracts, also allowed the chemical composition of parts and provenance of the plant to be differentiated.

A phytochemical study of Aristolochia melastoma Manso has led to the isolation and identification of 20 known compounds, including aristolochic acids, sodium aristolochates, lignan, flavonoids, and nitro phenylethyl derivatives. Their structures were established by spectroscopic analysis. The presence of thalictricoside and secoisolariciresinol dimethyl ether diacetate is reported for the first time in the Aristolochiaceae family. In addition, the presence of nitro compounds in this species is significant.

Foram isoladas quatorze substâncias de Aristolochia giberti, entre elas, um novo triterpeno, (-)-onocera-8,8'-diol. Além destas, 3-hidróxipropanoato, acetato e formato foram detectados por técnicas de RMN, o que sugere que estas substâncias sejam derivadas do 2-butinodioato, não detectável por RMN de ¹H. As análises dos óleos essenciais de caules e folhas, por CG-EM e quimiometria, mostraram grande similaridade entre as espécies cultivadas no Brasil e aquelas na Argentina, o que permitiu confirmar a identificação da espécie e diferenciar os óleos de acordo com as partes da planta.

Fourteen compounds were isolated from Aristolochia giberti. These included a new triterperne, (-)-onocera-8,8'-diol. In addition, 3-hydroxypropanoate, acetate, and formate were detected by NMR techniques, which suggests that they are derivatives from 2-butynedioate, which is not detected by ¹H NMR. GC-MS and chemometric analyses of essential oils from stems and leaves showed great similarity between this cultivated species in Brazil and that in Argentina, which allowed us to confirm the species identity and to differentiate the oils according to the plant parts.

From hexane fraction of methanol extract of leaves of Tapirira guianensis (Anacardiaceae) were obtained lupeol, 24-methylenecycloartan-3-ol, phytol, α-amyrin, β-amyrin, sitosterol, sitostenone, glycosyl sitosterol, as well as sitosterol esterified with palmitic and stearic acids. Phytol, α-amyrin and β-amyrin esterified with fatty acids were also identified from same extract. The EtOAc extract besides the norisoprenoids (6S,7E,9S)-6,9-dihydroxy-megastigma-4,7-dien -3-one 9-O-β-glucopyranoside and (6S,7E,9R)-6,9-dihydroxy-megastigma-4,7-dien-3-one 9-O-β-glucopyranoside also afforded kaempferol 3-O-rhamnoside, kaempferol 3-O-arabinofuranoside, quercetin 3-O-rhamnoside, and kaempferol. The structural elucidation of isolated compounds were based on UV, IR, MS, ¹H and 13C NMR data analysis.

Foram isolados de galhos de Aristolochia gehrtii a cis-N-feruloil-3-O-metildopamina, um derivado hemiacetálico do 5-hidroximetilfurfural, e vinte e dois compostos conhecidos. Entre estes compostos estão cinco lignanas, três terpenos, seis alcalóides dos quais cinco são alcamidas, dois derivados do ácido benzóico e seis derivados constituídos pelo grupo feniletil. As estruturas dos compostos isolados foram determinadas por métodos espectroscópicos e comparação de dados físicos e espectroscópicos dos compostos com aqueles disponíveis na literatura.

From the stems of Aristolochia gehrtii, the cis-N-feruloyl-3-O-methyldopamine and a hemiacetal derivative of 5-hydroxymethylfurfural were isolated, together with twenty-two known compounds. These compounds include five lignans, three terpenes, six alkaloids (five alkamides), two benzoic acid derivatives, and six phenethyl derivatives. The structures of the isolated compounds were determined by means of spectroscopic methods and comparison with literature data.