Abstract The Brazilian native species Cestrum intermedium, known as mata-boi, induces hepatotoxicity and death when ingested by cattle. While most studies on this species focus on toxicological features, our study is the first to describe the anatomy and in vitro biological activities of Cestrum intermedium. We investigated adult leaves and stems by histochemistry, described their anatomy, performed physical-chemical analysis, determined in vitro antioxidant and antimicrobial activities, and identified secondary metabolites. A few noteworthy anatomical features were the anomocytic stomata on the abaxial surface and the absence of trichomes, in addition to the circular shaped petiole with two projections on the adaxial surface. Histochemical analysis showed chemical markers such as alkaloids, usually reported as toxic, and terpenoids. Potassium nitrate (ATR-FTIR) and lupeol palmitate (NMR) were detected on the crude stem extract. Thermogravimetric and physical-chemical analysis provided fingerprint parameters for the species. Minimal Inhibitory Concentration (MIC) assay revealed that Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans were weakly inhibited by extract samples. Chloroform and ethyl acetate fractions presented high phenolic content, which resulted in in vitro antioxidant activity. These novel features expand the knowledge about this species, considering that previous studies mainly focused on its toxicity. Our study also provided characteristics that may help in avoiding misidentification between Cestrum members, especially when taxonomic keys cannot be employed, as in the absence of flowers and fruits.

Abstract This study aimed to investigate the anatomy and histochemistry of Mollinedia clavigera leaves and stems through photonic microscopy and scanning electron microscopy. Noteworthy features of leaves were: presence of paracytic stomata on both surfaces; simple as well as bifurcate non-glandular trichomes; prismatic calcium oxalate crystals; flat-convex midrib with a central and two dorsal bundles; concave-convex petiole with a single vascular bundle in open archh. Stems were cylindrical and showed prismatic and styloid crystals in the pith. Histochemical analysis detected lipophilic and phenolic compounds, starch grains and lignified elements such as brachysclereids and fibers. These features may assist in future identifications and quality control of M. clavigera, avoid misidentification between other genus members, once species and genus studies are scarce.

The present study was undertaken to assess the potential uses of the essential oil obtained from Ocotea nutans (Nees) Mez. The hydrodistilled essential oil from O. nutans leaves was analyzed by gas chromatography-mass spectrometry. Fifty-eight compounds representing 87,29% of the total leaf essential oil components were identified, of which biciclogermacrene(11.41%), germacrene-D (4.89%), bisabolol-11-ol(3.73%) and spathulenol (3.71%) were the major compounds. The essential oil from O. nutans were tested for antibacterial activity using the minimum inhibitory concentracion (MIC) method, Artemia salina method, larvicidal activity in Aedes aegypti, and antioxidant capacity.The antioxidant activity measured by the phosphomolybdenum complex and Prussian blue method had positive results. The minimum inhibitory concentration for the microorganisms tested allowed moderate inhibitionfor Enterococcus faecalis(MIC=500 µg/mL). Artemia salina were toxic to the organisms in the study (LC50= 71,70 μg /mL). The essential oil showed remarkable larvicidal activity potencial (LC50= 250 µg/mL). The present results showed thatO. nutans essential oil has potential biological uses.

ABSTRACT The essential oil composition of the Ocotea bicolor, native plant of Brazil, was studied for the first time. The essential oil of the leaf was obtained by hydrodistillation and analyzed by GC/MS. The analytical procedure revealed a predominance of sesquiterpenes, δ-cadinene (7.39%), β-sesquiphellandrene (6.67%), β-elemene (5.41%) and α-cadinol (5,23%). The essential oil was submitted to brine shrimp toxicity evaluation, antioxidant and antibacterial tests. The antioxidant activity by the formation of phosphomolybdenum complex method presented positive results. The minimum inhibitory concentration (MIC) values were higher than 1000 μg/mL for the microorganisms tested. Toxicity activity revealed LC50 results of 40.10 (μg/mL), being toxic to the organisms in this study.