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Artepillin C, drupanin, and plicatin B are prenylated phenylpropanoids that naturally occur in Brazilian green propolis. In this study, these compounds and eleven of their derivatives were synthesized and evaluated for their in vitro antimicrobial activity against a representative panel of oral bacteria in terms of their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. Plicatin B (2) and its hydrogenated derivative 8 (2′,3′,7,8-tetrahydro-plicatin B) were the most active compounds. Plicatin B (2) displayed strong activity against all the bacteria tested, with an MIC of 31.2 μg/mL against Streptococcus mutans, S. sanguinis, and S. mitis. On the other hand, compound 8 displayed strong activity against S. mutans, S. salivarius, S. sobrinus, Lactobacillus paracasei (MIC = 62.5 μg/mL), and S. mitis (MIC = 31.2 μg/mL), as well as moderate activity against Enterococcus faecalis and S. sanguinis (MIC = 125 μg/mL). Compounds 2 and 8 displayed bactericidal effects (MBC: MIC ≤ 4) against all the tested bacteria. In silico studies showed that the complexes formed by compounds 2 and 8 with the S. mitis, S. sanguinis, and S. mutans targets (3LE0, 4N82, and 3AIC, respectively) had energy score values similar to those of the native S. mitis, S. sanguinis, and S. mutans ligands due to the formation of strong hydrogen bonds. Moreover, all the estimated physicochemical parameters satisfied the drug-likeness criteria without violating the Lipinski, Veber, and Egan rules, so these compounds are not expected to cause problems with oral bioavailability and pharmacokinetics. Compounds 2 and 8 also had suitable ADMET parameters, as the online server pkCSM calculates. These results make compounds 2 and 8 good candidates as antibacterial agents against oral bacteria. [ABSTRACT FROM AUTHOR]

Citrus canker, which is caused by Xanthomonas citri, is a severe disease that affects citrus plants worldwide. This paper aimed to compare, for the first time, the chemical composition and anti-Xanthomonas citri activities of essential oils from Schinus molle fresh and dry leaves (EO-FL and EO-DL, respectively). Anti-X. citri activity of spathulenol, the major constituent of oils, was also evaluated. Activities were screened by the broth microdilution method on 96‐well culture plates. Three major constituents were identified in EO-FL and EO-DL by GC-MS and GC-FID: spathulenol, β-caryophyllene and caryophyllene oxide. EO-DL (MIC = 31.25 µg/mL), EO-FL (MIC = 62.5 µg/mL) and spathulenol (MIC = 100 µg/mL) were active against X. citri strains (resistant, tolerant and sensitive to copper). Even though results showed that in vitro potential of EO-FL, EO-DL and spathulenol against X. citri, further in vivo studies are needed to prove their applicability to the biocontrol of citrus canker. [ABSTRACT FROM AUTHOR]

Spiranthera odoratissima A. St.-Hil. (Rutaceae) has been popularly used against abdominal pain and rheumatism. This study aimed at extracting hexane from S. odoratissima (HE-SO) leaves to identify and quantify its volatile compounds by GC-MS and GC-FID and to evaluate its antifungal, antileishmanial and antibacterial activities in vitro. HE-SO exhibited antileishmanial activity against promastigote forms of Leishmania (Leishmania) amazonensis (IC50 = 38.16 µg/mL) and was moderately active against Xylella fastidiosa (MIC = 100 µg/mL). HE-SO also showed remarkable antifungal potential against six strains of Candida species, i. e., C. albicans, C. glabrata, C. parapsilosis, C. krusei, C. tropicalis and C. orthopsilosis. The lowest MIC values were between 31.25 and 250 µg/mL. Spathulenol (20.2%), τ-cadinol (11.7%), α-cadinol (9.4%), caryophyllene oxide (9.2%) and isoaromadendrene epoxide (8.2%) were the major components identified in HE-SO. Therefore, results showed that HE-SO has promising antileishmanial and antifungal actions. [ABSTRACT FROM AUTHOR]

Eugenia species have been appreciated for their edible fruits and medicinal properties. This paper aims to investigate the chemical composition and in vitro antileishmanial, antifungal and antiproliferative activities of essential oil from aerial parts of Eugenia pyriformis (EP-EO). The oil showed strong antileishmanial activity against promastigote forms of Leishmania amazonensis (IC50 = 2.16 µg/mL). It also exhibited high antifungal activity against Malassezia furfur (MIC = 30 µg/mL), which was determined by the broth microdilution method. Its antiproliferative activity was evaluated against the following cells: GM07429A (normal cell), MCF-7 (human breast adenocarcinoma), HeLa (human cervical adenocarcinoma) and M059J (human glioblastoma). Its major constituents, which were determined by GC-FID and GC-MS, were limonene (14.8%), nerolidol (11.0%), α-cadinol (10.3%), caryophyllene oxide (9.9%) and β-pinene (7.1%). These results showed, for the first time, the effectiveness of EP-EO as a natural product which has promising biological activities, a fact that enables its ethnopharmacological use. [ABSTRACT FROM AUTHOR]

Nectandra megapotamica is a tree species that naturally occurs in the Atlantic Forest, Brazil. This paper aims to investigate the chemical composition and in vitro antibacterial, antileishmanial and antiproliferative activities of essential oil from N. megapotamica leaves (NM-EO). It displayed high antibacterial activity against Streptococcus mutans, S. sobrinus, Prevotella nigrescens and Bacteroides fragilis. NM-EO also exhibited high antileishmanial activity against promastigote forms of Leishmania amazonensis. Its antiproliferative activity was evaluated against the following cells: GM07429A (normal cell), MCF-7 (human breast adenocarcinoma), HeLa (human cervical adenocarcinoma) and M059J (human glioblastoma). Its major components, which were determined by GC-FID and GC-MS, were α-bisabolol (13.7%), bicyclogermacrene (10.9%), (E,E)-farnesene (10.6%), Z-caryophyllene (9.5%) and (E)-β-farnesene (7.0%). These results suggest that N. megapotamica, a Brazilian plant, shows initial evidence of a new and alternative source of substances of medicinal interest. [ABSTRACT FROM AUTHOR]

In Brazilian folk medicine, Protium heptaphyllum is used to treat inflammatory conditions and to hasten wound repair. This paper aims to investigate the chemical composition and the in vitro antibacterial effects of the essential oils (EOs) obtained from P. heptaphyllum leaves and ripe and unripe fruits against a representative panel of oral pathogens. The GC-FID and GC-MS analysis revealed that the major components determined in P. heptaphyllum essential oils were myrcene (59.0%), β-elemene (17.2%), limonene (12.9%), spathulenol (12.6%), α-cubebene (11.6%), germacrene D (10.6%), trans-nerolidol (9.8%), and α-cadinol (8.8%). The essential oils of the ripe and unripe fruits showed the strongest antibacterial activity against the anaerobic bacteria Prevotella nigrescens (MIC = 50 µg/mL). The leaf essential oil displayed very promising activity against Streptococcus mutans (MIC = 50 µg/mL) and Streptococcus mitis (MIC = 62.5 µg/mL). The antibacterial activity of EOs against oral pathogens is also described for the first time. [ABSTRACT FROM AUTHOR]

In this study, the chemical composition and antibacterial and antiproliferative potential of the essential oil obtained from fresh leaves of Psidium myrtoides (PM-EO) against oral pathogens and human tumour cell lines were investigated for the first time. GC-FID and GC-MS analyses showed that trans-β-caryophyllene (30.9%), α-humulene (15.9%), α-copaene (7.8%), caryophyllene oxide (7.3%) and α-bisabolol (5.3%) are the major constituents of PM-EO. The antibacterial activity of PM-EO against a panel of oral pathogens was investigated in terms of their minimal inhibitory concentrations (MIC) using the broth microdilution method. PM-EO displayed moderate activity against Streptococcus mitis (MIC = 100 μg/mL), S. sanguinis (MIC = 100 μg/mL), S. sobrinus (MIC = 250 μg/mL), and S. salivarius (MIC = 250 μg/mL), and strong activity against S. mutans (MIC = 62.5 μg/mL). The antiproliferative activity in normal (GM07492A, lung fibroblasts) and tumour cell lines (MCF-7, HeLa, and M059 J) was performed using the XTT assay. PM-EO showed 50% inhibition of normal cell growth at 359.8 ± 6.3 μg/mL. Antiproliferative activity was observed against human tumour cell lines, with IC50 values significantly lower than that obtained for the normal cell line, demonstrating IC50 values for MCF-7 cells (254.5 ± 1.6 μg/mL), HeLa cells (324.2 ± 41.4 μg/mL) and M059 J cells (289.3 ± 10.9 μg/mL). Therefore, the cytotoxicity of PM-EO had little influence on the antibacterial effect, since it showed antibacterial activity at lower concentrations. Our results suggest that PM-EO is a promising source of new antibacterial and antitumour agents. [ABSTRACT FROM AUTHOR]

The species Inga laurina is native to the Brazilian Cerrado. There are no studies about the chemical composition and biological activities of extracts of this endangered species. The ethanolic extract and its successive fractions are rich in phenolic compounds and presented good antifungal activities. HPLC/MS-MS/MS and H1/C13 analysis led to the identification of seventeen compounds, most of which are gallic acid derivatives, myricetin and quercetin glycosides. The ethyl acetate fraction (EAF) contained high levels of total phenolics, expressed in milligrams of gallic acid equivalents per gram of extract (475.3 ± 1.9 mg GAE gextract-1) and flavonoids expressed in milligrams of quercetin equivalents per gram of extract (359.3 ± 10.6 mg QE gextract-1). This fraction was active against fungi of the Candida genus. The EAF showed MIC value 11.7 μg mL-1 against C. glabrata and a selectivity index of 1.6 against Vero cells. The flavonol glycoside myricetin-3-O-rhamnoside was isolated for the first time from the Inga laurina. These results make I. laurina a promising plant as a source of pharmaceutical and biological active antifungal compounds. [ABSTRACT FROM AUTHOR]