Undescribed Triterpenes from the Leaves of Syzygium myrsinifolium with Their α-Glucosidase and α-Amylase Inhibition Activity.

Two undescribed triterpenes, syzyfolium A (1) and syzyfolium B (2), together with twelve known compounds, terminolic acid (3), actinidic acid (4), piscidinol A (5), threo-dihydroxydehydrodiconiferyl alcohol (6), lariciresinol-4-O-ß-D-glucoside (7), icariol A2 (8), 14ß,15ß-dihydroxyklaineanone (9), garcimangosone D (10), (+)-catechin (11), myricetin-3-O-α-L-rhamnopyranoside (12), quercitrin (13), and 3, 4, 5-trimethoxyphenyl-(6'-O-galloyl)-O-ß-D-glucopyranoside (14) were isolated from the leaves of Syzygium myrsinifolium. Their chemical structures were determined by IR, HR-ESI-MS, 1D and 2D NMR spectra. Compounds 3 and 4 inhibited significantly α-glucosidase with IC50 values of 23.99 and 36.84, respectively, and compounds 1 and 2 inhibited significantly α-amylase with IC50 values of 35.48 and 43.65 µM, respectively.

Evaluation of the Antiproliferative Potential of Yellow Jaboticaba (Myrciaria glazioviana) Extracts Against Human Cervical Cancer (HeLa cells line) and the Analysis of Their Chemical Composition by HPLC-HRESIMS.

Cervical cancer is a specific type of cancer that affects women around the world, with an incidence of 604 thousand new cases per year and 341 thousand deaths. There is a high demand for new effective antineoplastic drugs with few side effects. In this sense, recent research highlights the potential of compounds of natural origin in treating and preventing different types of cancer. Myrciaria glazioviana is a Brazilian native species belonging to the Myrtaceae family, which has previously described biological activities such as antimicrobial, anti-inflammatory, and antioxidant properties. This study aims to evaluate the anticancer activity of the dichloromethane extract (MGD) and ethyl acetate extract (MGA) of M. glazioviana leaves against human cervical cancer cell line (HeLa), as well as to identify their bioactive compounds. Using HPLC-HRESIMS technique, ten compounds were characterized in both samples: quinic acid, ellagic acid, Tri-O-methyl ellagic acid, two derivatives of Tetra-O-methyl flavellagic acid, quercetrin, Di-O-methyl ellagic acid, and three derivatives of pentamethyl coruleoellagic acid. Through MTT assays using HeLa cells and NIH/3T3 cells, it was observed that MGD and MGA were selective against tumor cells, with IC50 values of 24.31 and 12.62 µg/mL, respectively. The samples induced the tumor cell death by apoptosis, as evidenced by the activation of caspases 3/7, cell shrinkage, and pyknotic nuclei. Both samples were also able to inhibit the migration of HeLa cells after 24 hours of treatment, indicating a potential antimetastatic effect. Therefore, the present research highlights the antiproliferative and antimigratory potential of this species against HeLa cells.

NMR and multivariate methods: Identification of chemical markers in extracts of pedra-ume-caá and their antiglycation, antioxidant, and enzymatic inhibition activities.

INTRODUCTION: In Brazil, the plant group popularly known as "pedra-ume-caá" is used in folk medicine for the treatment of diabetes, and its raw material is commonly sold. OBJECTIVE: The aim of the study was to apply a method for chemical identification of extracts of dry pedra-ume-caá leaves using HPLC-high-resolution mass spectrometry (HRMS) and NMR and develop a multivariate model with NMR data to authenticate commercial samples. In addition, to evaluate the biological activities of the extracts. MATERIALS AND METHODS: Dry extracts of Myrcia multiflora, Myrcia amazonica, Myrcia guianensis, Myrcia sylvatica, Eugenia punicifolia leaves, and 15 commercial samples (sold in Manaus and Belém, Brazil) were prepared by infusion. All the extracts were analysed using HPLC-high-resolution mass spectrometry (HRMS), NMR, principal component analysis (PCA), and hierarchical cluster analysis (HCA). The antidiabetic effect of extracts was evaluated according to enzymatic inhibition. Their content of total phenols, cell viability, and antioxidant and antiglycation activities were also determined. RESULTS: HPLC-HRMS and NMR analysis of these extracts permitted the identification of 17 compounds. 1H NMR data combined with multivariate analyses allowed us to conclude that catechin, myricitrin, quercitrin, and gallic and quinic acids are the main chemical markers of pedra-ume-caá species. These markers were identified in 15 commercial samples of pedra-ume-caá. Additionally, only the extracts of M. multiflora and E. punicifolia inhibited α-glucosidase. All the extracts inhibited the formation of advanced glycation end products (AGEs) and showed free-radical-scavenging activity. These extracts did not present cytotoxicity. CONCLUSION: This study revealed the chemical markers of matrices, and it was possible to differentiate the materials marketed as pedra-ume-caá. Moreover, this study corroborates the potential of these species for treating diabetes.

Tautomeric cinnamoylphloroglucinol-monoterpene adducts from Cleistocalyx operculatus and their antiviral activities.

Guided by 1H NMR spectroscopic experiments using the characteristic enol proton signals as probes, three pairs of new tautomeric cinnamoylphloroglucinol-monoterpene adducts (1-3) were isolated from the buds of Cleistocalyx operculatus. Their structures with absolute configurations were established by spectroscopic analysis, modified Mosher's method, and quantum chemical electronic circular dichroism calculation. Compounds 1-3 represent a novel class of cinnamoylphloroglucinol-monoterpene adducts featuring an unusual C-4-C-1' linkage between 2,2,4-trimethyl-cinnamyl-ß-triketone and modified linear monoterpenoid motifs. Notably, compounds 1-3 exhibited significant in vitro antiviral activity against respiratory syncytial virus (RSV).

A terpene synthase supergene locus determines chemotype in Melaleuca alternifolia (tea tree).

Leaf oil terpenes vary categorically in many plant populations, leading to discrete phenotypes of adaptive and economic significance, but for most species, a genetic explanation for the concerted fluctuation in terpene chemistry remains unresolved. To uncover the genetic architecture underlying multi-component terpene chemotypes in Melaleuca alternifolia (tea tree), a genome-wide association study was undertaken for 148 individuals representing all six recognised chemotypes. A number of single nucleotide polymorphisms in a genomic region of c. 400 kb explained large proportions of the variation in key monoterpenes of tea tree oil. The region contained a cluster of 10 monoterpene synthase genes, including four genes predicted to encode synthases for 1,8-cineole, terpinolene, and the terpinen-4-ol precursor, sabinene hydrate. Chemotype-dependent null alleles at some sites suggested structural variants within this gene cluster, providing a possible basis for linkage disequilibrium in this region. Genotyping in a separate domesticated population revealed that all alleles surrounding this gene cluster were fixed after artificial selection for a single chemotype. These observations indicate that a supergene accounts for chemotypes in M. alternifolia. A genetic model with three haplotypes, encompassing the four characterised monoterpene synthase genes, explained the six terpene chemotypes, and was consistent with available biparental cross-segregation data.

Family Myrtaceae: The treasure hidden in the complex/diverse composition.

Myrtaceae is one of the most important plants families, being regarded as the eighth largest flowering plant family. It includes many genera of utmost ecological and economical importance distributed all over the world. This review aimed to report the latest studies on this family focusing on certain widely used plants including Eucalyptus sp., Eugenia sp. (Eugenia uniflora, Eugenia sulcata), Syzygium sp. (Syzygium aromaticum and Syzygium cumini), Psidium sp., Pimenta dioica, Myrtus sp. (Myrtus communis), Myrciaria sp. and Melaleuca alternifolia. The extraction of bioactive compounds has been evolving through the optimization of conventional methods and the use of emerging technologies. Supercritical CO2 was applied for essential oils and ultrasound for polyphenols leading to extracts and essential oils rich in bioactive compounds. Advances in the field of encapsulation and delivery systems showed promising results in the production of stable essential oils nanoemulsions and liposomes and the production of plant extracts in the form of nanoparticles. Moreover, a significant increase in the number of patents was noticed especially the application of Myrtaceae extracts in the pharrmacuetucal field. The applications of ceratin plants (Pimenta dioica, Melaleuca alternifolia, Syzygium aromaticum essential oils or Myrciaria cauliflora peel extract) in food area (either as a free or encapsulated form) also showed interesting results in limiting microbial spoilage of fresh meat and fish, slowing oxidative degradation in meat products, and inhibiting aflatoxin production in maize. Despite the massive literature on Myrtaceae plants, advances are still necessary to optimize the extraction with environmentally friendly technologies and carry out risk assessment studies should be accomplished to harness the full potential in food, industrial and pharmaceutical applications.

Neither lysigenous nor just oil: Demystifying myrtaceous secretory cavities.

PREMISE: Leaf subepidermal secretory cavities are a notable trait in Myrtaceae, but their formation is still controversial because of the lack of consensus on their ontogeny among authors. Knowledge about the compounds present in these cavities has grown over the last few years, demonstrating that terpenoid-rich oils are not their unique content. These two points are the focus of this study on the ontogeny, structure, and contents of secretory cavities in neotropical Myrtaceae. METHODS: We used histochemical tests and Raman analysis to verify the basic chemical composition of the cavity contents of nine species. We studied the ontogeny of glands in one species, comparing aldehyde-fixed tissues and fresh sections mounted in an inert medium. RESULTS: We observed schizogenous development and appearance of the secretory cavities and found that sample processing may induce cell breakdown, which can be misinterpreted as lysigeny. The content of these cavities contains putative terpenes, resins, carbonyl groups, and flavonoids. CONCLUSIONS: Our findings support the hypothesis that the lysigenous appearance of the oil glands is a technical artifact. These tissue distortions must be considered when interpreting the development of this type of secretory structure. Moreover, the basic analyses of chemical constituents show for the first time that the glands of neotropical Myrtaceae are potential reservoirs of some compounds such as flavonoids previously reported as novelties for a few other myrtaceous species. Because some of them are non-lipid compounds, the idea that the glands are just oil repositories is no longer applicable.

Acaricidal activity of a 2-methoxy-clovan-9-ol rich fraction from Eugenia copacabanensis (Myrtaceae) extract on Rhipicephalus microplus (Acari: Ixodidae).

Rhipicephalus microplus (Ixodidae, canestrini, 1888) is an invasive ectoparasite of cattle which causes high economic losses in emerging countries such as Brazil. Phytochemical compounds have been tested as an alternative to synthetic acaricides due to potentially lower mammalian toxicity. This study evaluated the acaricidal activity against R. microplus of the 2-methoxy-clovan-9-ol rich fraction obtained from Eugenia copacabanensis Kiaersk.leaves, a little known Myrtaceae species from the Brazilian Atlantic Forest. This fraction was obtained by maceration with methanol, partition with n-hexane and purification by normal-phase column chromatography. GC-MS, 1H and 13C NMR and IR analysis contributed to the identification of a major compound as the sesquiterpene 2-methoxy-clovan-9-ol, reported for the first time for the Myrtaceae family. The fraction was tested against R. microplus unfed larvae and engorged females and a 93% larval mortality was observed at the concentration of 50 mg mL-1. Lower concentrations of the solution tested demonstrated a significant difference in egg mass weight, hatching and control percentage. Experiments with 50.0 mg mL-1 showed significative results, with lower concentration and maximum efficacy for both assays. The IC50 values for unfed larvae and engorged females were 21.76 and 11.13 mg mL-1, respectively. These results were similar to those obtained in other studies with isolated botanical compounds and essential oils. The lower IC50 for engorged females than for unfed R. microplus larvae had also been described for other plant materials, including plants from the same Myrtaceae family. The present result suggested different mechanisms of action of the compound on the reproductive biology of engorged females, improving its effect against egg viability. These results are important for tick control, suggesting that 2-methoxy-clovan-9-ol could be a potential natural acaricidal product against both R. microplus unfed larvae and engorged females.

Genus Pimenta: An Updated Comprehensive Review on Botany, Distribution, Ethnopharmacology, Phytochemistry and Biological Approaches.

Pimenta is a genus of flowering plants belonging to family Myrtaceae, native to the West Indies, Mexico, and South America. Numerous traditional uses were reported as anti-inflammatory, analgesic, antipyretic, sedative, diuretic, and sexual stimulant. This article aims to provide a comprehensive overview of the botany, traditional uses, phytochemical profile, and biological activities of genus Pimenta for future exploration of plant-based drugs and therapeutic approaches. The data were collected (up to date as of October 1, 2023) from several databases such as Web of Science, google scholar, science direct, Pubmed and Proquest. Pimenta species were reported to include various classes of phytochemicals like tannins, saponins, flavonoids, phenylpropanoids, monoterpenes, sesquiterpenes and essential oils. Quercetin glycosides and eugenol derivatives were the predominant compounds of this genus. Several biological activities have been reported such as antihypertensive, antioxidant, antimicrobial, antiviral, histidine decarboxylase inhibition, hypoglycemic, anticancer, anti-inflammatory, analgesic, antipyretic, acaricidal, anxiolytic, anti-depressant and anti-estrogenic. Several scientific reports have been published on various isolated phytochemicals and pharmacological properties of Pimenta species that confirm its ethnobotanical and traditional history. However, in vivo studies on different extracts and their phytoconstituents, alongside mechanistic analysis deserve more attention for drug researchers to provide better guidance to utilize Pimenta plants as medicinal resources for herbal formulations in different approaches.

New Isopropyl Chromone and Flavanone Glucoside Compounds from the Leaves of Syzygium cerasiforme (Blume) Merr. & L.M.Perry and Their Inhibition of Nitric Oxide Production.

A new isopropyl chromone (1) and a new flavanone glucoside (2) together with eleven known compounds (3-13) were isolated from the leaves of Syzygium cerasiforme (Blume) Merr. & L.M.Perry. Their structures were elucidated as 5,7-dihydroxy-2-isopropyl-6,8-dimethyl-4H-chromen-4-one (1), 5,7-dihydroxyflavanone 7-O-ß-D-(6''-O-galloylglucopyranoside) (2), strobopinin (3), demethoxymatteucinol (4), pinocembrin-7-O-ß-D-glucopyranoside (5), (2S)-hydroxynaringenin-7-O-ß-D-glucopyranoside (6), afzelin (7), quercetin (8), kaplanin (9), endoperoxide G3 (10), grasshopper (11), vomifoliol (12), litseagermacrane (13) by the analysis of HR-ESI-MS, NMR, and CD spectral data. Compounds 1, 2, 5, 6 and 10 inhibited NO production on LPS-activated RAW264.7 cells with IC50 values of 12.28±1.15, 8.52±1.62, 7.68±0.87, 9.67±0.57, and 6.69±0.34 µM, respectively, while the IC50 values of the other compounds ranging from 33.38±0.78 to 86.51±2.98 µM, compared to that of the positive control, NG -monomethyl-L-arginine acetate (L-NMMA) with an IC50 value of 32.50±1.00 µM.

Undescribed Phenolic Glycosides from Syzygium attopeuense and Their Inhibition of Nitric Oxide Production.

Four undescribed phenolic glycosides including three stilbene derivatives (1 and 3) and sodium salt of 3 (2), and a chalcone glycoside (4), together with thirteen known compounds (5-17) were isolated from the leaves of Syzygium attopeuense (Gagnep.) Merr. & L.M.Perry. Their chemical structures were elucidated to be (Z)-gaylussacin (1), 6''-O-galloylgaylussacin sodium salt (2), 6''-O-galloylgaylussacin (3), 4'-O-[ß-D-glucopyranosyl-(1→6)-glucopyranosyl]oxy-2'-hydroxy-6'-methoxydihydrochalcone (4), gaylussacin (5), pinosilvin 3-O-ß-D-glucopyranoside (6), myricetin-3-O-(2''-O-galloyl)-α-L-rhamnopyranoside (7), myricetin-3-O-(3''-O-galloyl)-α-L-rhamnopyranoside (8), myricetin-3-O-α-L-rhamnopyranoside (9), quercitrin (10), myricetin-3-O-ß-D-glucopyranoside (11), myricetin-3-O-ß-D-galactopyranoside (12), quercetin 3-O-α-L-arabinopyranoside (13), myricetin-3-O-2''-O-galloyl)-α-L-arabinopyranoside (14), (+)-gallocatechin (15), (-)-epigallocatechin (16), and 3,3',4'-trimethoxyellagic acid 4-O-ß-D-glucopyranoside (17) by the analysis of HR-ESI-MS, 1D and 2D NMR spectra in comparison with the previously reported data. Compounds 1-3, 5, and 6 significant inhibition of NO production in LPS-activated RAW264.7 cells, with IC50 values ranging from 18.37±1.38 to 35.12±2.53 µM, compared to a positive control (dexamethasone) with an IC50 value of 15.37±1.42 µM.

First report of Myrtle Rust caused by Austropuccinia psidii on Myrcianthes pungens (O. Berg) D. Legrand in Paraná state, Brazil.

Myrcianthes pungens is a tree fruit native to Brazil, unknown to a large part of the population, with fruit consumed only locally. In October 2022, at the experimental area at Universidade Tecnológica Federal do Paraná (UTFPR) in the Dois Vizinhos city, Paraná State, Brazil, symptoms of the disease were observed on mature leaves and fruits of 17 trees. Fungal fructifications were observed in the form of bright yellow uredinia containing a large mass of urediniospores on the surface and on the leaves and fruits that resembled the structures typical of a Myrtaceae rust pathogen. Leaves colonized by the fungus showed deformations, turning dark and rapidly causing senescence. In the orchard, the fungus affected 80% of the trees, with a severity of 40 to 45%. Diseased fruits (10) and leaves (10) (from each tree) were collected from 17 trees from different positions in the orchard. The observed structures (optical microscope) were hyaline and globose urediniospores (n = 30) which had pointed echinulate ornaments throughout their surface (Cummins & Hiratsuka, 2003), (n = 30, 14.84 µm × 21.1 µm). These characteristics were similar to the morphological characteristics of the genus Austropuccinia previously described by Young et al. (2019). A strain was selected as a representative for molecular characterization and pathogenicity tests (accession no. APM001). For molecular identification, the internal transcribed spacer (ITS) region (Kroop et al., 1995), b-tubulin (TUB2), and translation elongation factor 1-alpha (TEF) (Machado et al., 2015) were amplified by PCR and sequenced. The sequences were deposited in GenBank (accession nos. ITS: OQ442638, TUB2: OQ506543, and TEF: OQ506542). Phylogenetic analyses using Bayesian inference grouped the isolate with the type species of Austropuccinia psidii with a high posterior probability (1.0). Pathogenicity tests used conidial suspensions (1x105urediniospores/ml). Four branches containing twenty leaves and two young asymptomatic fruits were individually inoculated with 1.5 mL of urediniospore suspension using a bottle with a spray nozzle cap. The branches were protected with perforated transparent plastic bags moistened with distilled water and incubated at room temperature (18 ºC to 25 ºC). Three replicates (pathogen and control) spread on different trees in the orchard were used in this experiment. After seven days, symptoms of rust appeared on the leaves and on the tenth day of the fruits, with morphological characteristics similar to those previously reported. Control branches showed no fungal growth. The inoculation test was repeated, confirming the symptoms. This is the first report of the incidence of rust caused by A. psidii on leaves and fruits of M. pungens in Paraná State. The importance of the disease is due to the high percentage of fruit loss due to rapid rot and drop caused by the pathogen attack.

Erysiphe elevata causing powdery mildew on Eucalyptus urophylla × E. camaldulensis in China.

Eucalyptus urophylla × E. camaldulensis, named Chiwei eucalypt, is a hybrid species widely used in China. Many of its clones are cultivated for afforestation due to cold tolerance, high yield, high strength and disease resistance. Clone LH1 is planted extensively for its high stability and machinability in South China. In December 2021, severe powdery mildew signs were observed on clone LH1 in Zhanjiang, Guangdong (N28°8'29"; E110°17'5"). Whitish powder principally appeared on both abaxial and adaxial leaf surfaces. All plants were infected within about a week and above 90% leaves were diseased, which resulted in abnormal growth and shrinkage of leaves. Hyphae with single, lobed appressoria were hyaline, septate, branched, 3.3-6.8 µm (ave. 4.9 µm, n>50) wide. Conidiophores with a straight to flexuous foot-cell (14.7-46.1×5.4-9.7 µm, ave. 25.8×7.9 µm, n>30) were erect, hyaline, 2-septate, unbranched, 35.4-81.8 × 5.7-10.7 (ave. 56.7×8.7 µm, n>50). Conidia were solitary, hyaline, cylindrical to elliptical, 27.7-46.6 ×11.2-19.0 (ave. 35.7×16.6 µm, n>50). Chamothecia were not found on infected trees. The further identification was confirmed by partial sequences of internal transcribed spacer (ITS), large submit rRNA gene (LSU), Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), glutamine synthetase (GS), and RNA polymerase II second largest subunit (RPB2) gene. A very small amount of mycelia and spores from voucher specimens CCAS-ASBF-1 and CCAS-ASBF-2 were deposited in the herbarium of Guangdong Ocean University. Specimens were PCR amplified and sequenced with primer pairs ITS1/ITS4 (White et al 1990), LROR/LR7 (Moncalvo et al 1995), PMGAPDH1/PMGAPDH3R, GSPM2/GSPM3R and PmRpb2_4/ PMRpb2_6R (Bradshaw, et al. 2022), respectively. BLASTn results showed that ITS (OP270019 and OQ380937), LSU (OP270018 and OQ380938), GAPDH, GS and RPB2 (OQ414445- OQ414450) were above 99% identical with those of E. elevata on Catalpa bignonioides (ITS: AY587013) (Cook et al 2004), Plumeria rubra (ITS: MH985631) (Yeh et al 2019), Cerbera manghas (ITS: MZ379159; LSU: MZ379160) (Mukhtar et al 2022), and Eucalyptus camaldulensis (LSU: LC177375-6) (Meebon et al. 2017), and above 99% identical with those of Erysiphe vaccinii FH00941201 on Vaccinium corymbosum (ITS: ON073869; RPB2: ON119159; GS: ON075687) and FH00112205 on V. vacillans (ITS: ON073870; GAPDH: ON075646) (Bradshaw et al 2022). This is the first sequence data for non rDNA of E. elevata. In an ITS tree phylogenetic analysis with Maximum likelihood (ML) method showed the fungus clustered in a highly supported clade with E. elevata and E. vaccinii. In a multi-locus tree, E. elevata grouped in a sister position to E. vaccinii FH00941201. Thus, the pathogen was identified as E. elevata based on morphology, DNA BLASTn and phylogenetic analysis (Braun and Cook 2012). Pathogenicity tests were conducted on healthy leaves of 1-year-old potted plants. Ten leaves were cleaned with sterile water, inoculated by gently dusting conidia from single lesion on the naturally infected leaves, and then covered with plastic bags containing wet absorbent cotton. Non-inoculated leaves served as controls. Symptoms developed on all inoculated leaves 3 to 5 days after inoculation, and the fungus was identical to the original fungus on the infected leaves, whereas control plants remained symptomless. This is the first report of powdery mildew caused by E. elevata on Eucalyptus sp. from China. This finding is helpful for land managers to diagnose and control the disease.

Essential oil from leaves of Myrciaria floribunda (H. West ex Willd.) O. Berg has antinociceptive and anti-inflammatory potential.

Myrciaria floribunda is a plant that is distributed across different Brazilian biomes such as the Amazon, Caatinga, Cerrado, and Atlantic Forest, and it possesses antioxidant, antimicrobial, and anticancer properties. The antinociceptive and anti-inflammatory properties of the essential oil from M. floribunda leaves (MfEO) were examined in this study using mouse models. Gas chromatography-mass spectrometry was employed to describe the oil, and the results revealed that δ-cadinene, bicyclogermacrene, α-cadinol, and epi-α-muurolol predominated in the chemical profile. The oil stimulated a decrease in nociception in the chemical and thermal models used to evaluate acute antinociceptive activity. Findings from the use of pain pathway blockers to study the presumed underlying mechanism indicated opioid pathway activity. The anti-edematogenic effect, decreased cell migration, and generation of pro-inflammatory cytokines provided evidence of the anti-inflammatory potential of the essential oil from M. floribunda. According to this research, the essential oil from M. floribunda can effectively alleviate acute pain and inflammation.

Essential Oils of Five Syzygium Species Growing Wild in Vietnam: Chemical Compositions and Antimicrobial and Mosquito Larvicidal Potentials.

The essential oils of five Vietnamese Syzygium species (Syzygium levinei, S. acuminatissimum, S. vestitum, S. cumini, and S. buxifolium) were first hydro-distilled and analyzed using GC-FID/MS (gas chromatography-flame ionization detection/mass spectrometry). Monoterpene hydrocarbons, sesquiterpene hydrocarbons, and oxygenated sesquiterpenoids were the main chemical classes in these oils. All these essential oils showed good-excellent antimicrobial activities against Gram-positive bacteria Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus, and the yeast Candida albicans. S. levinei leaf essential oil, rich in bicyclogermacrene (25.3%), (E)-ß-elemene (12.2%), (E)-caryophyllene (8.2%), and ß-selinene (7.4%), as well as S. acuminatissimum fruit essential oil containing (E)-caryophyllene (14.2%), α-pinene (12.1%), caryophyllene oxide (10.9%), ß-selinene (10.8%), α-selinene (8.0%), and α-humulene (5.7%), established the same MIC value of 8 µg/mL against E. faecalis and B. cereus, which were much better than the positive control streptomycin (MIC 128-256 µg/mL). The studied essential oils showed the potential to defend against mosquitoes since they caused the 24 and 48 h LC50 values of less than 50 µg/mL against the growth of Culex quinquefasciatus and Aedes aegypti larvae. Especially, S. buxifolium leaf essential oil strongly inhibited Ae. aegypti larvae with 24 and 48 h LC50 values of 6.73 and 6.73 µg/mL, respectively, and 24 and 48 h LC90 values of 13.37 and 10.83 µg/mL, respectively. These findings imply that Vietnamese Syzygium essential oils might have potential for use as supplemental antibacterial agents or as "green" alternatives for the control of mosquitoes.

Molluscicidal and Cercaricidal Effects of Myrciaria floribunda Essential Oil Nanoemulsion.

Schistosomiasis is a tropical disease transmitted in an aqueous environment by cercariae from the Schistosoma genus. This disease affects 200 million people living in risk areas around the world. The control of schistosomiasis is realized by chemotherapy, wastewater sanitation, health education, and mollusk control using molluscicidal agents. This work evaluates the effects of a nanoemulsion containing essential oil from Myrciaria floribunda leaves as a molluscicidal and cercaricidal agent against Biomphalaria glabrata mollusks and Schistosoma mansoni cercariae. The Myrciaria floribunda essential oil from leaves showed nerolidol, ß-selinene, 1,8 cineol, and zonarene as major constituents. The formulation study suggested the F3 formulation as the most promising nanoemulsion with polysorbate 20 and sorbitan monooleate 80 (4:1) with 5% (w/w) essential oil as it showed a smaller droplet size of approximately 100 nm with a PDI lower than 0.3 and prominent bluish reflection. Furthermore, this nanoemulsion showed stability after 200 days under refrigeration. The Myrciaria floribunda nanoemulsion showed LC50 values of 48.11 µg/mL, 29.66 µg/mL, and 47.02 µg/mL in Biomphalaria glabrata embryos, juveniles, and adult mollusks, respectively, after 48 h and 83.88 µg/mL for Schistosoma mansoni cercariae after 2 h. In addition, a survival of 80% was observed in Danio rerio, and the in silico toxicity assay showed lower overall human toxicity potential to the major compounds in the essential oil compared to the reference molluscicide niclosamide. These results suggest that the nanoemulsion of Myrciaria floribunda leaves may be a promising alternative for schistosomiasis control.

Phylogenomics and continental biogeographic disjunctions: insight from the Australian starflowers (Calytrix).

PREMISE: Continental-scale disjunctions and associated drivers are core research interests in biogeographic studies. Here, we selected a species-rich Australian plant genus (Calytrix; Myrtaceae) as a case study to investigate these patterns. Species of this endemic Australian starflower genus have a disjunct distribution across the mesic fringes of the continent and are largely absent from the arid center. METHODS: We used high-throughput sequencing to generate unprecedented resolution and near complete species-level nuclear and plastid phylogenies for Calytrix. BioGeoBEARS and biogeographic stochastic mapping were used to infer ancestral areas, the relative contributions of vicariance and dispersal events, and directionality of dispersal. RESULTS: Present-day disjunctions in Calytrix are explained by a combination of scenarios: (1) retreat of multiple lineages from the continental center to the more mesic fringes as Australia became progressively more arid, with subsequent extinction in the center as well as (2) origination of ancestral lineages in southwestern Australia (SWA) for species-rich clades. The SWA biodiversity hotspot is a major diversification center and the most common source area of dispersals, with multiple lineages originating in SWA and subsequently spreading to the adjacent arid Eremaean region. CONCLUSIONS: Our results suggest that major extinction, as a result of cooling and drying of the Australian continent in the Eocene-Miocene, shaped the present-day biogeography of Calytrix. We hypothesize that this peripheral vicariance pattern, which is similar to the African Rand flora, may explain the disjunctions of many other Australian plant groups. Further studies with densely sampled phylogenies are required to test this hypothesis.

Contribution of spathulenol to the anti-nociceptive effects of Psidium guineense.

Objectives: Araçá-verdadeiro is the popular name of Psidium guineense (Myrtaceae), whose fruits and leaves are used in Brazilian folk medicine for treatment of inflammation and pain. The focus of the present research was an investigation of the anti-nociceptive, and anti-inflammatory effects of the essential oil from P. guineense (EOPG) leaves, and of spathulenol. The anxiolytic and antidepressive effects associated with chronic pain were also investigated in models of acute or persistent nociception or/and inflammatory pain.Methods and Results: Oral treatment with EOPG (10-100 mg/kg) or spathulenol (10 mg/kg) significantly inhibited formalin-induced nociceptive responses, both sensitivity to cold and edema. Oral treatment with EOPG (10 mg/kg) and spathulenol (10 mg/kg) did not reduce locomotor activity (open field test). Local administration of spathulenol (1000 µg/paw) significantly prevented formalin-induced nociceptive sensitivity to cold and paw edema, and carrageenan-induced mechanical hyperalgesia, paw edema and sensitivity to cold. In the Freund's complete adjuvant (CFA) model, oral treatment with EOPG (10 mg/kg) or spathulenol (10 mg/kg) for 21 days significantly inhibited all analyzed parameters. The percentage maximal inhibition by spathulenol was 76.00% (mechanical hyperalgesia), 71.90% (cold response), 85.00% (edema), 77.16% (myeloperoxidase activity), 97.72% (time in the closed arms in the elevated plus maze), and 49.00% (immobility time in the tail suspension test), in the CFA model. Models employed male Swiss mice, except for the CFA test, which employed C57bL6 male mice (n=6 /group).Conclusion: This study demonstrates that EOPG is an anti-nociceptive and anti-hyperalgesic agent, in acute and continuous treatment, and an anxiolytic and antidepressive agent when tested with the chronic pain experimental state.

Genetic Diversity and Population Structure of Psidium Species from Restinga: A Coastal and Disturbed Ecosystem of the Brazilian Atlantic Forest.

The Atlantic Forest is one of the most threatened biomes in the world. Here, we use a common set of microsatellite markers to assess the genetic diversity and population structure of three species from the genus Psidium (P. guajava, P. macahense, and P. guineense), located in a disturbed environment of the Atlantic Forest, the restinga, in Espírito Santo, Brazil. Psidium guajava populations presented the highest number of alleles (95) followed by P. guineense (81) and P. macahense (68). The genetic variability was high (P. guajava = 0.71; P. guineense = 0.74; P. macahense = 0.63), with greater variation within populations (72 to 84%) than among populations (15 to 27%), reflecting elevated values of genetic differentiation (P. guajava, FST: 0.15; P. macahense, ØST: 0.27; P. guineense, ØST: 0.21). The populations were clustered into two main groups and considered moderately structured. This is the first report of genetic studies and evidence of polyploidy to P. macahense. Our results may provide information that can be used in management and conservation strategies, to preserve the diversity of Psidium populations.

Essential Oils from Different Myrtaceae Species from Brazilian Atlantic Forest Biome - Chemical Dereplication and Evaluation of Antitrypanosomal Activity.

Chagas Disease (CD), caused by flagellate protozoan Trypanosoma cruzi, is a Neglected Tropical Diseases (NTD) that affect approximately seven million people worldwide with a restrict therapeutical arsenal. In the present study, the essential oils from 18 Myrtaceae species were extracted, chemically dereplicated, and evaluated in vitro against T. cruzi. From these, eight essential oils were considered promising (IC50 <10 µg/mL and SI>10) against the protozoan: Eugenia florida, E. acutata, E. widgrenii, Calyptranthes brasilienses, C. widgreniana, Plinia cauliflora, Campomanesia xanthocarpa, and Psidium guajava. Multivariate data analysis pointed out (E)-caryophyllene, α-humulene, limonene, caryophyllene oxide, and α-copaene playing an important role in the anti-T. cruzi activity. The obtained results demonstrated the potential of essential oils of Myrtaceae species as valuable sources of bioactive compounds against T. cruzi.