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Abstract Polyploidy, a numerical alteration of the karyotype, is one of the most important mechanisms in plant speciation and diversification, but could also be detected among populations, the cytotypes. For example, Psidium cattleyanum, a polyploid complex, has chromosome numbers ranging from 2n=3x=33 to 2n=12x=132. Polyploidization causes an increase in DNA content, and both modifications may cause alteration in plant growth, physiology, and epigenetics. Based on this possibility, here we aim to verify the influence of the polyploidization on the production of P. cattleyanum essential oil chemotypes. Differences in the DNA contents, as a proxy to different ploidies, were observed and three distinct chemotypes were identified through the chromatographic profile analysis. The Psidium cattleyanum DNA content and qualitative and quantitative characteristics of the essential oils presented a positive relationship. Plants with higher DNA contents presented higher levels of oil production, which was mostly composed of hydrogenated sesquiterpenes, while plants with lower DNA contents produced lower amount of oil, which was mostly composed of hydrogenated monoterpenes. Based on the importance of essential oils, polyploid plants, which present higher DNA content, are recommended as possible matrices for the propagation of new plants with the potential to produce major compounds of agronomic and pharmacological interest.

Abstract The search for more environmental friendly herbicides, aiming at the control of agricultural pests, combinated with less harmfulness to human health and the environment has grown. An alternative used by researchers is the application of products of secondary plant metabolism, which are investigated due to their potential bioactivities. Thus, species belonging to the Myrtaceae family are potential in these studies, since this family is recognized for having high biological activity. A species belonging to this genus is Psidium cattleyanum, which has a medicinal effect and its fruits are used in human food. Thus, the objective of this research was to evaluate and compare the phyto-cyto-genotoxicity of aqueous and ethanolic leaf extracts of the specie P. cattleyanum, from plant bioassays, as well as to identify the main classes of compounds present in the extracts. For this, the extracts were prepared, characterized and biological tests were carried out by evaluating, in seeds and seedlings of lettuce and sorghum, the variables: percentage of germination, germination speed index, root growth and aerial growth; and in meristematic lettuce cells the variables: mitotic phases, mitotic index, nuclear alterations and chromosomal alterations. Flavones, flavonones, flavonols, flavononols, flavonoids, alkaloids, resins, xanthones and anthraquinone glycoside were characterized in the ethanolic extract. Both evaluated extracts, in the highest concentration, inhibited the initial plant development. All treatments caused alterations in the mitotic phases and inhibited mitotic index. In addition, the treatments promoted an increase in nuclear and chromosomal alterations. The mechanism of action presented was aneugenic, clastogenic and determined in epigenetic alterations. The ethanolic extract was more cytotoxic, since it had a more expressive effect at a lower concentration. Despite the cytotoxicity of the extracts under study, they promoted alterations at lower levels than the glyphosate positive control.

Ginger ( Zingiber officinale ), a globally distributed plant, is widely used in the industry for its flavourings, seasonings, and beverages. However, maintaining its quality and volatile components during processing has posed a challenge. This study, therefore, aimed to assess the impact of drying time (24, 48, and 72h) in a circulation oven at 40 °C on the chemical composition and yield of fresh and dried ginger. The essential oils were extracted using the hydrodistillation method, and their chemical analysis was conducted using gas chromatography. The drying time in the oven directly influenced the essential oil yield, with a longer time resulting in a higher yield. We identified 27 compounds in the essential oils, varying their predominance depending on the drying time. The PCA analysis revealed that the drying time can lead to the formation of different chemotypes for ginger, indicating that altering the drying time can yield significantly different chemical profiles.

Strawberry is a food rich in bioactive compounds with great antioxidant potential. However, due to the high incidence of pests that affect crop cultivation, phytosanitary management still lacks control methods for agroecological cultivation. Thus, the present research aimed to evaluate the chemical composition and the potential of the essential oil of the leaves of Piper macedoi in the control of Cerosipha forbesi in laboratory and semi-field conditions. The concentration of essential oil in the leaves of P. macedoi that showed the highest mortality was 2.0 ml/L of oil, with a mortality above 91% under laboratory conditions. A mortality rate of 80% for all concentrations tested was observed after 24 h in all conditions tested. Thus, using essential oil from the leaf of P. macedoi can be a highly viable strategy in managing the aphid C. forbesi since it showed high mortality rates with small doses of oil.

Among the several terpenes existing in nature, Citronellal, a monoterpene aldehyde, deserves to be highlighted for its biological properties that have been pointed out in numerous studies. This work aimed to conduct a literature review on its biological properties. Citronellal is a prominent compound in the essential oils of Cymbopogon genus plants. Apart from being employed as a fragrance ingredient in aromas, fragrances, and cosmetics, it is also used as an intermediate in synthesising (-)-menthol. Various studies have demonstrated Citronellal's potential as an antibacterial compound, particularly anti- Staphylococcus and Escherichia bacteria. Citronellal also has antifungal properties against several fungi, especially fungi of the genus Candida . The studies found showed that Citronellal also has insecticidal, acaricidal, antiparasitic, anaesthetic, antiviral, antioxidant, antinociceptive, cardioprotective, antihypertensive, anti-inflammatory, antidiabetic, and anticancer properties.

Tetranychus urticae , popularly known as spider mite, is a pest that causes several economic losses to crops. Thus, this work evaluated the effect of essential oils from the leaves of Piper macedoi and Piper arboreum on managing T. urticae . The chemical compounds present in essential oils were identified by gas chromatography. Tests were carried out to evaluate the acaricidal activity by fumigation effect and direct contact with T. urticae . The results showed that LC 50 values for the essential oils of P. macedoi and P. arboreum in the fumigation effect were 16.15 and 50.53 µL L -1 air, respectively. Using the contact application route, the LC 50 values for the essential oil of P. macedoi was 17.16 µL mL -1 , and for P arboreum , it was 15.17 µL mL -1 . So, this work showed that essential oils of Piper macedoi and Piper arboreum could be used as possible alternative to managing T. urticae.

The Croton genus is known for its various biological properties, which inspired this study to investigate the anti-bacterial pro-perties and chemodiversity of the essential oils of three Croton species: Croton blanchetianus , Croton jacobinensis , and Croton nepetifolius . The essential oils were characterised by gas chromatography (GC-MS) and demonstrated anti-bacterial activity against Staphylococcus aureus and Escherichia coli using the disc diffusion method. The essential oil composition of C. blanchetianus showed bicyclogermacrene (16.04%) and spathulenol (16.44%) as the main compounds. In C. jacobinensis , bicyclogermacrene (22.04%), caryophyllene (17.95%), and β-phellandrene (12.30%) were the most prevalent. Meanwhile, C. nepetifolius's essential oil consisted mainly of bicyclogermacrene (17.69%), caryophyllene (15.15%), and germacrene D (11.78%). The principal component analysis (PCA) results showed three distinct chemotypes for each Croton species, suggesting that they have well-defined and unique chemical profiles. Interestingly, the three Croton species demonstrated activity only against Staphylococcus aureus bacteria.

Tomato is one of the most produced and consumed fruits in the world. However, it is a crop that faces several phytosanitary problems, such as fusarium wilt, caused by Fusarium oxysporum . Thus, this study aimed to evaluate citronella and melaleuca essential oils in vitro potential in the fungus F. oxysporum management. The chemical identification of the components in the essential oils was performed by gas chromatography with flame ionization and mass spectrometer detectors. The IC 50 and IC 90 were determined by linear regression and the percentage of inhibition of the fungus by analysis of variance. The major compounds in citronella essential oil were citronellal, Geraniol, and citronellol; in melaleuca (tea tree) oil were terpinen-4-ol and α-terpinene. Both oils promoted more significant inhibition at concentrations of 1.5 and 2.5 μL/mL, besides not presenting significant differences with commercial fungicides, confirming the high potential for using this control method in agriculture.

Cutaneous and visceral leishmaniasis are public health problems in Africa, Asia, Europe, and America. The treatment has a high cost and toxicity. Thus, this work aims to evaluate the leishmanicidal activity of alpha-bisabolol and its three synthetic derivatives, P1, P2, and P3, on the promastigotes and amastigotes Leishmania infantum and L. amazonensis forms. Alpha-bisabolol showed the lowest IC 50 with 3.43 for L. amazonensis promastigotes, while P1 was the most toxic for L. infantum with an IC 50 of 9.10. The derivative P3 was better for the amastigote form, with an IC 50 of 3.39 for L. amazonensis . All the compounds effectively decreased the intracellular load of amastigote and its ability to turn promastigote again. Thus, alpha-bisabolol and its three synthetic derivatives were effective in their leishmanicidal activity. Therefore, it can be an option for developing new treatments against leishmaniasis.

Two-spotted spider mite causes significant damage to various crops, often requiring synthetic acaricides for their control. However, the frequent use of these products causes several environmental problems. Thus, this work aimed to evaluate the acaricidal action, using the application by fumigation on female adults of Tetranychus urticae of essential oil from the leaves of Rosmarinus officinalis L., and its major compound, α -pinene. In addition, the essential oil was characterized by gas chromatography and mass spectrometry. α -pinene was the compound with the highest relative area in the oil (29.2%). In fumigation tests, α-pinene showed more significant toxicity than rosemary essential oil on two-spotted spider mite females with LC 50 and LC 90 values of 1.58 and 49.61 µL/L air, showing the impact of the chemical composition of the essential oil on the biological activity.

Encounters between flowers and invertebrates are key events for the functioning of tropical forests. Assessing the structure of networks composed of the interactions between those partners leads to a better understanding of ecosystem functioning and the effects of environmental factors on ecological processes. Gathering such data is, however, costly and time-consuming, especially in the highly diverse tropics. We aimed to provide a comprehensive repository of available flower-invertebrate interaction information for the Atlantic Forest, a South American tropical forest domain. Data were obtained from published works and "gray literature," such as theses and dissertations, as well as self-reports by co-authors. The data set has ~18,000 interaction records forming 482 networks, each containing between one and 1061 interaction links. Each network was sampled for about 200 h or less, with few exceptions. A total of 641 plant genera within 136 different families and 39 orders were reported, with the most abundant and rich families being Asteraceae, Fabaceae, and Rubiaceae. Invertebrates interacting with these plants were all arthropods from 10 orders, 129 families, and 581 genera, comprising 2419 morphotypes (including 988 named species). Hymenoptera was the most abundant and diverse order, with at least six times more records than the second-ranked order (Lepidoptera). The complete data set shows Hymenoptera interacting with all plant orders and also shows Diptera, Lepidoptera, Coleoptera, and Hemiptera to be important nodes. Among plants, Asterales and Fabales had the highest number of interactions. The best sampled environment was forest (~8000 records), followed by pastures and crops. Savanna, grasslands, and urban environments (among others) were also reported, indicating a wide range of approaches dedicated to collecting flower-invertebrate interaction data in the Atlantic Forest domain. Nevertheless, most reported data were from forest understory or lower strata, indicating a knowledge gap about flower-invertebrate interactions at the canopy. Also, access to remote regions remains a limitation, generating sampling bias across the geographical range of the Atlantic Forest. Future studies in these continuous and hard-to-access forested areas will yield important new information regarding the interactions between flowers and invertebrates in the Atlantic Forest. There are no copyright restrictions on the data set. Please cite this data paper if the data are used in publications and teaching events., (© 2022 The Ecological Society of America.)

Polyploidy, a numerical alteration of the karyotype, is one of the most important mechanisms in plant speciation and diversification, but could also be detected among populations, the cytotypes. For example, Psidium cattleyanum, a polyploid complex, has chromosome numbers ranging from 2n=3x=33 to 2n=12x=132. Polyploidization causes an increase in DNA content, and both modifications may cause alteration in plant growth, physiology, and epigenetics. Based on this possibility, here we aim to verify the influence of the polyploidization on the production of P. cattleyanum essential oil chemotypes. Differences in the DNA contents, as a proxy to different ploidies, were observed and three distinct chemotypes were identified through the chromatographic profile analysis. The Psidium cattleyanum DNA content and qualitative and quantitative characteristics of the essential oils presented a positive relationship. Plants with higher DNA contents presented higher levels of oil production, which was mostly composed of hydrogenated sesquiterpenes, while plants with lower DNA contents produced lower amount of oil, which was mostly composed of hydrogenated monoterpenes. Based on the importance of essential oils, polyploid plants, which present higher DNA content, are recommended as possible matrices for the propagation of new plants with the potential to produce major compounds of agronomic and pharmacological interest.

We investigated whether essential oil and aqueous and ethanolic extracts from M. vittoriana leaves have phytotoxic effects on the germination and initial development, and cytogenotoxic effects on the cell cycle, of model plants. The essential oil and extracts of M. vittoriana were characterized and used as treatments in phytotoxicity and cytotoxicity tests. The results indicated a reduction in germinative parameters and plant growth, with the higher concentrations of extracts and essential oil having the most evident effects. The cell cycle was also affected with a reduction of the mitotic index and the presence of chromosomal and nuclear alterations. All treatments showed clastogenic and aneugenic modes of action. The results can be associated with the synergistic effects of metabolites found in the extracts and essential oil, mainly the presence of the sesquiterpene germacrene D in the essential oil and of catechins, saponins, and tannins in the extracts. These substances inhibit plant germination and growth, confirming the phytotoxic effects of M. vittoriana in plant models, which should now be tested under field conditions.

The search for more environmental friendly herbicides, aiming at the control of agricultural pests, combinated with less harmfulness to human health and the environment has grown. An alternative used by researchers is the application of products of secondary plant metabolism, which are investigated due to their potential bioactivities. Thus, species belonging to the Myrtaceae family are potential in these studies, since this family is recognized for having high biological activity. A species belonging to this genus is Psidium cattleyanum, which has a medicinal effect and its fruits are used in human food. Thus, the objective of this research was to evaluate and compare the phyto-cyto-genotoxicity of aqueous and ethanolic leaf extracts of the specie P. cattleyanum, from plant bioassays, as well as to identify the main classes of compounds present in the extracts. For this, the extracts were prepared, characterized and biological tests were carried out by evaluating, in seeds and seedlings of lettuce and sorghum, the variables: percentage of germination, germination speed index, root growth and aerial growth; and in meristematic lettuce cells the variables: mitotic phases, mitotic index, nuclear alterations and chromosomal alterations. Flavones, flavonones, flavonols, flavononols, flavonoids, alkaloids, resins, xanthones and anthraquinone glycoside were characterized in the ethanolic extract. Both evaluated extracts, in the highest concentration, inhibited the initial plant development. All treatments caused alterations in the mitotic phases and inhibited mitotic index. In addition, the treatments promoted an increase in nuclear and chromosomal alterations. The mechanism of action presented was aneugenic, clastogenic and determined in epigenetic alterations. The ethanolic extract was more cytotoxic, since it had a more expressive effect at a lower concentration. Despite the cytotoxicity of the extracts under study, they promoted alterations at lower levels than the glyphosate positive control.

Background: The Atlantic Forest is one of the most threatened biomes in the world. Despite that, this biome still includes many areas that are poorly known floristically, including several protected areas, such as the "Floresta Nacional do Rio Preto" ("Flona do Rio Preto"), located in the Brazilian State of Espírito Santo. This study used a published vascular plant species list for this protected area from the "Catálogo de Plantas das Unidades de Conservação do Brasil" as the basis to synthesise the species richness, endemism, conservation and new species occurrences found in the "Flona do Rio Preto"., New Information: The published list of vascular plants was based on field expeditions conducted between 2018 and 2020 and data obtained from herbarium collections available in online databases. Overall, 722 species were documented for the "Flona do Rio Preto", 711 of which are native to Brazil and 349 are endemic to the Atlantic Forest. In addition, 60 species are geographically disjunct between the Atlantic and the Amazon Forests. Most of the documented species are woody and more than 50% of these are trees. Twenty-three species are threatened (CR, EN and VU), while five are Data Deficient (DD). Thirty-two species are new records for the State of Espírito Santo. Our results expand the knowledge of the flora of the Atlantic Forest and provide support for the development of new conservation policies for this protected area., (Anderson Alves-Araújo, Marina M Moreira, Tatiana T Carrijo, Lúcia G Lohmann, Adriana Q Lobão, Alana F Scheidegger, Aline D Firmino, Aline Vieira de Melo Silva, Álvaro Nepomuceno, Amélia C Tuler, André MA Amorim, André LC Moreira, Braz AP Cosenza, Brenno G Sossai, Christian Silva, Claudia R Lopes, Daniele Monteiro, Dayvid R Couto, Duane F Lima, Eduardo C Dalcin, Eliana Ramos, Elton J Lírio, Fatima Salimena, Felipe Alves de Oliveira, Fernanda RM Fraga, Filipe Torres-Leite, Guilherme M Antar, Gustavo H Shimizu, Haroldo C Lima, Herison Medeiros, Jaquelini Luber, Jheniffer A Christ, João Lanna, João Paulo F Zorzanelli, Joelcio Freitas, José FB Pastore, José IM Melo, Juliana Paula-Souza, Juliana RPM Oliveira, Leandro C Pederneiras, Leandro Freitas, Leandro L Giacomin, Leonardo D Meireles, Luis AE Silva, Luiz JS Pinto, Luiz Menini Neto, Marcelo Trovó, Mário L Garbin, Marli P Morim, Michel Ribeiro, Nelson TL Pena, Paulo H Labiak, Pedro H Cardoso, Pedro L Viana, Pedro LR Moraes, Quélita S Moraes, Raquel F Zorzanelli, Renara N Amaral, Renata C Asprino, Renato Goldenberg, Ricardo Magnago, Ricardo S Couto, Sandrine C Dutra, Saúl E Hoyos-Gómez, Tamara AF Vieira, Thiago B Flores, Valquíria F Dutra, Víctor S Miranda, Vitor C Manhães, Rafaela C Forzza.)

The world population growth has raised concerns about food security. Agricultural systems are asked to satisfy a growing demand for food with increasingly limited resources, and simultaneously still must reduce the impacts on the environment. This scenario encourages the search for safe and sustainable production strategies. Reducing losses in the production process can be one of the main ways to guarantee food safety. In fruticulture, it is estimated that more than 50% of the production can be lost between harvest and the final consumer due to postharvest diseases caused by phytopathogenic fungi. The fungi of the genus Colletotrichum are opportunistic and are associated with several diseases, being the anthracnose the most relevant in terms of the quality and yield losses in fruit species around worldwide. To control these diseases, the use of synthetic fungicides has been the main instrument utilized, however, because of their phytotoxicity to human health, the environment, and strong selection pressure imposed by continuous applications, the fungicides have caused resistance in the pathogen populations. So reducing the excessive application of these products is indispensable for human health and for sustainable Agriculture. Towards this purpose, research has been carried out to identify the phytopathological potentiality of essential oils (EOs) extracted from plants. Therefore, this review aims to contribute to the formation of knowledge bases, about the discoveries, recent advances, and the use of EOs as a strategy to alternatively control fungal disease caused by Colletotrichum spp. in postharvest fruits. Here, we provide valuable information exploring the application potential of essential oils as commercially useful biorational pesticides for food preservation, contributing to sustainable production and global food security., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Brazilian protected areas are essential for plant conservation in the Atlantic Forest domain, one of the 36 global biodiversity hotspots. A major challenge for improving conservation actions is to know the plant richness, protected by these areas. Online databases offer an accessible way to build plant species lists and to provide relevant information about biodiversity. A list of land plants of "Parque Nacional do Caparaó" (PNC) was previously built using online databases and published on the website "Catálogo de Plantas das Unidades de Conservação do Brasil." Here, we provide and discuss additional information about plant species richness, endemism and conservation in the PNC that could not be included in the List. We documented 1,791 species of land plants as occurring in PNC, of which 63 are cited as threatened (CR, EN or VU) by the Brazilian National Red List, seven as data deficient (DD) and five as priorities for conservation. Fifity-one species were possible new ocurrences for ES and MG states., New Information: "Parque Nacional do Caparaó" houses 8% of the land plant species endemic to the Brazilian Atlantic Forest, including 6% of its angiosperms, 31% of its lycophytes and ferns and 14% of its avascular plants. Twelve percent of the threatened species listed for the State of Espírito Santo and 7% listed for the State of Minas Gerais are also protected by PNC. Surprisingly, 79% of the collections analysed here were carried out in Minas Gerais, which represents just 21% of the total extension of the Park. The compiled data uncover a huge botanical collection gap in this federally-protected area., (Marina M Moreira, Tatiana T Carrijo, Anderson G Alves-Araújo, Alessandro Rapini, Alexandre Salino, Aline D Firmino, Aline P Chagas, Ana F A Versiane, André M A Amorim, Andrews V S da Silva, Amélia C Tuler, Ariane L Peixoto, Bethina S Soares, Braz A P Cosenza, Camila N Delgado, Claudia R Lopes, Christian Silva, Daniel E F Barbosa, Daniele Monteiro, Danilo Marques, Dayvid R Couto, Diego R Gonzaga, Eduardo Dalcin, Elton John de Lirio, Fabrício S Meyer, Fátima R G Salimena, Felipe A. Oliveira, Filipe S Souza, Fernando B Matos, Gabriel Depiantti, Guilherme M Antar, Gustavo Heiden, Henrique M Dias, Hian C F Sousa, Isabel T F V Lopes, Isis M Rollim, Jaquelini Luber, Jefferson Prado, Jimi N Nakajima, João Lanna, João Paulo F Zorzanelli, Joelcio Freitas, José F A Baumgratz, Jovani B S Pereira, Juliana R P M Oliveira, Kelly Antunes, Lana S Sylvestre, Leandro C Pederneiras, Leandro Freitas, Leandro L Giacomin, Leonardo D Meireles, Leonardo N Silva, Luciana C Pereira, Luís Alexandre E Silva, Luiz Menini Neto, Marcelo Monge, Marcelo L O Trovó, Marcelo Reginato, Marcos E G Sobral, Mario Gomes, Mário L Garbin, Marli P Morim, Nayara D Soares, Paulo H E Labiak, Pedro L Viana, Pedro H Cardoso, Pedro L R Moraes, Pedro B Schwartsburd, Quélita S Moraes, Raquel F Zorzanelli, Renara Nichio-Amaral, Renato Goldenberg, Samyra G Furtado, Thamara Feletti, Valquíria F Dutra, Vinícius R Bueno, Vinícius A O Dittrich, Rafaela C Forzza.)

Background: Isolated monoliths of granitic and/or gneissic rock rising abruptly from the surrounding landscape are known as inselbergs. Dome-shaped inselbergs are common throughout the Atlantic Forest in south-eastern Brazil, a region known as Sugarloaf Land (SLL). This study aimed to create the first checklist of vascular plant species occurring on lowland inselbergs in SLL, with a focus on vegetation islands. We used information from online databases, our own field sampling and data from previously-published studies. We found 548 vascular plant species (505 angiosperms; 43 ferns and lycophytes) belonging to 69 families and 212 genera. Of all identified species, 536 are native and 12 are naturalised., New Information: We updated the information currently available in Flora do Brasil 2020, as 59% of the angiosperms and 63% of the ferns and lycophytes on our checklist were not previously characterised as occurring on rock outcrops. As a first step towards generating a Virtual Herbarium of lowland inselberg vascular plants, we added barcode vouchers with images available online for 75% of the total number of vascular species. In the official lists of endangered species, 115 angiosperms and five ferns and lycophytes are mentioned. However, the conservation status of many species have not yet been evaluated (77% angiosperms; 88% ferns and lycophytes), thus this list is an important step towards their conservation. The information provided herein is essential for management programmes related to rock outcrops in Brazil as they are facing serious threats to conservation., (Luiza F. A. de Paula, Luísa O. Azevedo, Luana Paula Mauad, Leandro Jorge Telles Cardoso, João Marcelo Alvarenga Braga, Ludovic J.C. Kollmann, Claudio N. Fraga, Luiz Menini Neto, Paulo H. Labiak, Renato Mello-Silva, Stefan Porembski, Rafaela Campostrini Forzza.)

Among the various phenomena that can be modeled by Boolean networks, i.e., discrete-time dynamical systems with binary state variables, gene regulatory interactions are especially well known. Therefore, the analysis of Boolean networks is critical, e.g., to identify genetic pathways and to predict the effects of mutations on the cell functionality. Two methodologies (i.e., the semi-tensor product and the Gröbner bases over finite fields) have recently been proposed to tackle the problem of determining cycles and attractors (with the corresponding basin of attraction) for such systems. Here, it is shown that, by suitably coupling methodologies taken from these two fields (i.e., linear algebra and algebraic geometry), it is not only possible to determine cycles and attractors, but also to find closed-form solutions of the Boolean network. Such a goal is pursued by finding an immersion that recasts the Boolean dynamics in a linear form and by computing the closed-form solution of the latter system. The effectiveness of this technique is demonstrated by fully computing the solutions of the Boolean network modeling the differentiation of the Th-lymphocyte, a type of white blood cells involved in the human adaptive immune system., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The essential oil of Psidium guajava L. has been studied for pharmacological and industrial purposes, without considering the plant's genotype regarding the heterogeneity of its composition. The present study aimed to characterize the chemotype diversity of the essential oil extracted from the leaves of 22 genotypes of P. guajava grown in two different environments in the state of Espírito Santo, Brazil, and to identify the different chemical markers present in these plants. Essential oil from the leaves of the P. guajava genotypes was extracted by hydrodistillation, and its chemical composition was analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Thirty-three compounds were identified, comprising 87.5-99.0% of the total composition, with a prevalence of sesquiterpenes in all samples. The major compounds identified consisted of (E)-trans-Caryophyllene, α-Humulene, trans-Nerolidol, β-Bisabolene, β-Bisabolol, and Hinesol, the first of which was identified as a possible chemical marker for the species. Multivariate factor analysis of the chemical composition of P. guajava oil identified three chemotypes: Commercial - PAL, SEC, PS, PET, C7, C11, and C17MI, characterized by high levels of β-Selinene, α-Selinene, Hinesol, and 14-hydroxy-epi-(E)-caryophyllene, with β-Selinene and α-Selinene as the chemical markers; C10 and C13, exhibiting high levels of Elemol, trans-Nerolidol, trans-β-Eudesmol, and (2Z, 6Z)-Farnesol, which were indicated as chemical markers, and Cortibel - C1, C2, C3, C4, C5, C6, C8, C9, C12, C14, C15, C16, C17LI, which retained high levels of α-Cedrene, cis-α-Bergamotene, α-Humulene, Humulene epoxide, epi-α-Cadinol, β-Bisabolol, and α-Bisabolol, with β-Bisabolol and α-Bisabolol as the chemical markers. The use of guava genotypes with different chemotypes, that are agronomically favorable to fruit production and essential oil exploitation adds value to the crop and renders it more sustainable. Given guava crops produce large amounts of leaf biomass, resulting from successive prunings, the extraction of their essential oil, which retains commercially valuable compounds, can be feasible., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Semisynthetic phenol derivatives were obtained from the natural phenols: thymol, carvacrol, eugenol, and guaiacol through catalytic oxychlorination, Williamson synthesis, and aromatic Claisen rearrangement. The compounds characterization was carried out by 1 H NMR, 13 C NMR, and mass spectrometry. The natural phenols and their semisynthetic derivatives were tested for their antimicrobial activity against the bacteria: Staphylococcus aureus, Escherichia coli, Listeria innocua, Pseudomonas aeruginosa, Salmonella enterica Typhimurium, Salmonella enterica ssp. enterica, and Bacillus cereus. Minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values were determined using concentrations from 220 to 3.44 μg mL -1 . Most of the tested compounds presented MIC values ≤220 μg mL -1 for all the bacteria used in the assays. The molecular properties of the compounds were computed with the PM6 method. Through principle components analysis, the natural phenols and their semisynthetic derivatives with higher antimicrobial potential were grouped.

The Brazilian Atlantic Forest presents high levels of richness and endemism of several taxonomic groups. Within this forest, the Orchidaceae may be highlighted as the richest family of Angiosperms found there, and is highly threatened due to collection and habitat destruction. The inselbergs of the Brazilian Atlantic Forest are mostly unknown regarding their floristic composition, but the available information points to occurrence of endemic species, with adaptations to survive to this dry environment. The objectives of this study were to conduct a floristic survey of the Orchidaceae species on the Maciço do Itaoca, an inselberg located in the Northern region of the State of Rio de Janeiro, make a comparative analysis with other sites in Eastern Brazil, and discuss the geographic distribution, floristic relationships and conservation status of the orchid species present on the inselbergs. The floristic composition of the study area was compared with 24 other locations in Eastern Brazil (of which 13 are inselbergs) and the influence of the types of surrounding vegetation on the composition of the Orchidaceae flora on the inselbergs. On Maciço do Itaoca we recorded 18 species from 17 genera: Brasiliorchis picta, Brassavola tuberculata, Campylocentrum robustum; C sellowii, Catasetum luridum, Cattleya guttata, Cyclopogon congestus, Cyrtopodium glutiniferum, Leptotes bicolor, Lophiaris pumila, Miltonia moreliana, Oeceoclades maculata, Phymatochilum brasiliense, Prescottia plantaginifolia, Pseudolaelia vellozicola, Sarcoglottis fasciculata, Sophronitis cernua. and Vanilla chamissonis. The highest floristic similarity was with the Pedra da Botelha (0.43), an inselberg located in the North of Espírito Santo. This result is probably due to the similarity in altitude and distance from the coast in both areas despite the geographical distance between them. Apparently, little influence is exerted by the types of surrounding vegetation on the composition of the flora of inselbergs, due to their unique environmental characteristics which exert a strong selection pressure on plants that are adapted to survive on these inselbergs. The threats observed to the species on this inselberg are the same as for other inselbergs and include the collection of ornamental species, fire and quarrying. Specifically for the Maciço do Itaoca, a possibility for conservation may be the annexation of this area to the Desengano State Park, an important conservation area in the Northern of the State of Rio de Janeiro.

The highly selective oxychlorination of various phenols catalyzed by CuCl2 under mild conditions, in which chloride ions are used as chlorinating agents and dioxygen as a final oxidant, has been developed.