A espécie Poiretia bahiana, popularmente conhecida como arrudinha, arruda da serra ou arruda brava, tem uma ocorrência restrita aos campos rupestres da Chapada Diamantina, BA. Suas partes aéreas apresentam um aroma pungente e é usada pelo povo do local no controle de infestações por pulgas e no tratamento de hemorróidas, dores nas articulações e sinusite. Neste trabalho, relatamos a composição dos óleos voláteis obtidos das partes aéreas de cinco espécimes e do óleo volátil obtido dos frutos de um espécime de P. bahiana, os quais foram coletados em diferentes regiões da Chapada Diamantina. Nos óleos voláteis que foram analisados por CG-FID e CG-EM foram identificados vinte e nove componentes sendo que os dois principais foram a umbelulona, em concentrações entre 55,0% e 75,3%, e sabineno, em concentrações entre 10,3% e 25,2%. O óleo das partes aéreas de um espécime e o óleo dos frutos de outro espécime foram avaliados quanto às suas propriedades antimicrobianas contra seis bactérias, duas leveduras e cinco fungos filamentosos pelos ensaios de difusão em ágar e microdiluição. Os óleos exibiram atividade contra Escherichia coli, Salmonella choleraesuis, Proteus mirabilis, Staphylococcus aureus, Staphylococcus aureus resistente à meticilina (MRSA), Candida albicans, Cryptococcus neoformans, Cladosporium herbarum, Microsporum canis, Trichophyton rubrum e foram inativos contra Pseudomonas aeruginosa, Aspergillus fumigatus e Penicillium notatum. A toxicidade do óleo das partes aéreas foi determinada contra Artemia salina apresentando uma LC50 de 459,03 mg mL-1.

Poiretia bahiana known as "arrudinha", "arruda da serra" or "arruda brava", has its occurrence restricted to the rock fields (campo rupestre) areas in Chapada Diamantina, Bahia, northeastern region of Brazil. Its aerial parts present a pungent smell and have been used by local communities as fumigant for the control of infestation of fleas and in the treatment of hemorrhoids, articulations pain and sinusitis. This work reports the composition of the volatile oils from aerial parts of five specimens and of the essential oil from the fruits of one specimen of Poiretia bahiana that were harvested in four different places of Chapada Diamantina. Twenty nine components were identified from the oils analyzed by GC-FID and GC-MS. Umbellulone, in concentrations between 55.0% and 75.3% and sabinene, in concentrations between 10.3% and 25.2% are the major components. The oil from the aerial parts of one specimen and the oil of fruits of another specimen had their antimicrobial properties evaluated against six bacteria, two yeasts and five filamentous fungi by the agar diffusion method and microdilution assay. The in vitro results demonstrated that these essential oils exhibit antimicrobial activity against Escherichia coli, Salmonella choleraesuis, Proteus mirabilis, Staphylococcus aureus, methicilin resistant Staphylococcus aureus (MRSA), Candida albicans, Cryptococcus neoformans, Cladosporium herbarum, Microsporum canis, Trichophyton rubrum and are inactive against Pseudomonas aeruginosa, Aspergillus fumigatus and Penicillium notatum. The oil obtained from the aerial parts of one specimen displayed moderate toxicity against Artemia salina with a LC50 value of 459.03 mg mL-1.

This work report the seasonal variation of composition of the volatile oils from leaves and from flowers of Myrcia salzmannii harvested in the sand dunes of Salvador, Bahia, northeastern region of Brazil in the years 2001 and 2003. The oils were analyzed by GC-FID and GC-MS being identified 49 components. Nine essential oil samples of leaves collected on different months and years and one sample of flowers were analyzed. β-Caryophyllene and α-humulene were the only compounds present in all of the samples being the first the majority compound.

Eight triterpenes, maniladiol, breine, ursa-9(11):12-dien-3beta-ol, oleana-9(11):12-dien-3beta-ol, 3alpha-hydroxy-tirucalla-8,24-dien-21-oic acid, 3alpha-hydroxy-tirucalla-7,24-dien-21-oic, alpha and beta amyrines were isolated as binary mixtures obtained from the chloroform extract of the oil-resin of Protium heptaphyllum March. The identification of the compounds was based mainly in 13C NMR data and mass spectra. The diene and the tetracyclic acid triterpenes were not reported before in the literature as constituents of the studied resin.

Pimaradienes, including isopimaradienes, with an endocyclic double bond between C-9 and C-11 are uncommon compounds in nature. The diterpenoid pimar-9(11),15-dien-19-oic acid (1) was isolated from Mikania triangularis (Asteraceae) and the correct stereochemistry of 1was established by ¹H and 13C NMR studies of several oxidative products, mainly epoxides, of this compound and its double bond isomers.