Myrcia hatschbachii D. Legrand (Myrtaceae) is a native and endemic species from Brazil. This study investigated the essential oil composition, phytotoxic potential, in vitro toxicity, antioxidant properties and antibacterial activity of species. Chromatographic analysis of essential oil identified trans-calamanene, (E)-caryophyllene and spathulenol as major components. Antioxidant capacity was determined by the DPPH• scavenging method and phosphomolybdenum complex formation assay. Antibacterial activity was evaluated using the Minimal Inhibitory Concentration test, demonstrating that the essential oil was active toward Enterococcus faecalis and Staphylococcus aureus. Phytotoxic activity of essential oil was analyzed by testing interference on germination and growth of Lactuca sativa, demonstrating significant inhibition of the hypocotyls and radicles of seeds. Preliminary toxicity studies were determined using Artemia salina, resulting in an LC 50 of 409.92 µg/mL, and through hemolytic activity. The results of the phytotoxic activity point to a possible application for Myrcia hatschbachii in the development of natural herbicides and the in vitro toxicity assays suggests the performance of antitumoral activity tests, having in mind the prospection of antineoplastic drugs.

Several species of the Myrcia genus have been used in folk medicine to treat diabetes. Therefore, the aim of this work was to investigate the inhibitory activity of α-glucosidase and pancreatic lipase in the crude extract (EBF) and in the ethyl acetate fraction (FFA) of Myrcia hatschbachii, as well as to identify isolated phenolic compounds and to evaluate the antioxidant property and preliminary in vitro toxicity against Artemia salina. EBF (IC50: 3.21 μg/mL) and FFA (IC50: 1.14 μg/mL) showed inhibitory activity superior to acarbose (IC50: 193.65 μg/mL). In addition, they showed inhibitory effects of pancreatic lipase (IC50: 556.58 μg/mL for EBF and 532.68 μg/mL for FFA), antioxidant potential, absence of preliminary toxicity and presence of gallic andellagic acids in FFA. The relevant results in the inhibition of α-glucosidase and pancreatic lipase motivate new studies for the development of herbal medicines that assist in the treatment of diabetic patients.

Natural products, especially plants, have been investigated as sources of new substances with antimicrobial properties. In this context, the Myrcia genus is extensively researched for presenting such activities. This work aims to evaluate the antifungal, antibacterial, and antioxidant properties of extracts and fractions of stems of Myrcia hatschbachii, also to characterize two phenolic compounds. The antibacterial and antifungal activities were assessed by using the broth microdilution method. The ethyl acetate fraction (FGA) inhibited the growth of Candida albicans at a Minimum Inhibitory Concentration (MIC) of 15.6 µg/mL, presented 40% of phenolic compounds in its composition, obtained the most significant results in antioxidant methods (DPPH, FRAP, ABTS), besides the identification of ellagic and 3-O-methyl ellagic acids by NMR. Considering the relevant antifungal activity revealed by the fraction, new studies can be carried out to encourage the continuous search for antifungal alternatives.

The article has aimed to characterize the essential oil extracted from Ocotea diospyrifolia (Meisn.) Mez. leaves, in terms of its chemical composition and antioxidant, hemolytic, and phytotoxic potentials, as well as its toxicity against Artemia salina. The major constituents identified by CG-MS were δ-elemene, spathulenol, and β-atlantol. When screened for potential biological activities, the essential oil presented low toxicity against Artemia salina, and a capacity of lysing red blood cells. Also, the evaluation of its in vitro antioxidant activity, using the phosphomolybdenum method, showed better results when compared to butylhydroxytoluene (BHT) and rutin. In conclusion, the results obtained showed certain in vitro toxicity, leading to an interesting target for cytotoxicity evaluations of carcinoma cells.

Chemical constituents of Ocotea paranaensis (Lauraceae) essential oil and their antioxidant, anticancer and antimicrobial properties [Componentes químicos del aceite esencial de Ocotea paranaensis (Lauraceae) y sus propiedades antioxidantes, anticancer y antimicrobianas]

Plants have been seen as alternatives for researching natural antimicrobials and herbicides. The aim of this work was to evaluate the antibacterial, antifungal, and allelopathic properties of leaves extracts of Myrcia hatschbachii. The crude extract and fractions were obtained by Soxhlet apparatus. Antimicrobial activity was determined by the minimum inhibitory concentration (MIC) using the broth microdilution method. The ethyl acetate fraction showed activity against Candida albicans (MIC: 62.5 µg/mL), Staphylococcus aureus (MIC: 500 µg/mL), and Pseudomonas aeruginosa (MIC: 1000 µg/mL). Allelopathic activity evaluated the influence of crude extract and fractions on the germination and growth of Lactuca sativa. The crude extract and the chloroform fraction inhibited the growth of the radicle, while the hexane fraction inhibited the growth of the hypocotyl and radicle of lettuce seeds in all concentrations (100-1000 μg/mL). The biological potential of the species motivates further study of new antimicrobial and bioherbicidal agents.

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Research with fungi in search of substances with potential biological activity is gaining more prominence since they are sustainable sources of new molecules. Diplodia pinea is a phytopathogenic fungus found in forest species, which has shown few reports of molecules with biological activity and may present promising biotechnological potential. Thus, the objective of this study was to detect substances produced by this fungus in a liquid medium, under stressful conditions. A metabolite was detected in the alcoholic fraction characterized by X-ray diffraction as D-mannitol. This is the first description of this monosaccharide produced by D. pinea.