An evolutionary disruption of the buzz pollination syndrome in neotropical montane plants.

PREMISE: Under pollinator limitations, specialized pollination syndromes may evolve toward contrasting responses: a generalized syndrome with increased pollinator attraction, pollinator reward, and pollen transfer capacity; or the selfing syndrome with increased self-pollen deposition, but reduced pollinator attraction and pollen transfer capacity. The buzz-pollination syndrome is specialized to explore female vibrating bees as pollinators. However, vibrating bees become less-active pollinators at montane areas of the Atlantic Forest (AF) domain. This study investigated whether the specialized buzz-pollination syndrome would evolve toward an alternative floral syndrome in montane areas of the AF domain, considering a generalized and the selfing syndromes as alternative responses. METHODS: We utilized a lineage within the buzz-pollinated Miconia as study system, contrasting floral traits between montane AF-endemic and non-endemic species. We measured and validated floral traits that were proxies for pollinator attraction, reward access, pollen transfer capacity, and self-pollen deposition. We inferred the evolution of floral trait via phylogenetic comparative methods. RESULTS: AF-endemic species have selectively evolved greater reward access and more frequently had generalist pollination. Nonetheless, AF-endemic species also have selectively evolved toward lower pollen transfer capacity and greater self pollination. These patterns indicated a complex evolutionary process that has jointly favored a generalized and the selfing syndromes. CONCLUSIONS: The buzz pollination syndrome can undergo an evolutionary disruption in montane areas of the AF domain. This floral syndrome is likely more labile than often assumed, allowing buzz-pollinated plants to reproduce in environments where vibrating bees are less-reliable pollinators.

Chemical Composition of Extracts and Fractions from Miconia Ibaguensis (Melastomataceae) Leaves and Evaluation of Biological Activities.

The study aimed to assess the chemical composition of Miconia ibaguensis leaves extracts and fractions obtained from the ethanolic extract (EE), along with evaluating their antifungal, antibacterial, antidiabetic, and antioxidant activities. The ethyl acetate fraction (EAF) exhibited potent antifungal activity against Candida spp (1.95-3.90 µg mL-1) and potent antioxidant activity in the DPPH (1.74±0.07 µg mL-1), FRAP (654.01±42.09 µmol ETrolox/gsample), and ORAC (3698.88±37.28 µmol ETrolox/gsample) methods. The EE displayed inhibition against the α-amylase enzyme (8.42±0.05 µg mL-1). Flavonoids, hydrolysable tannins, triterpenoids, and phenolic acids, identified in the EE and fractions via (-)-HPLC-ESI-MS/MS analysis, were found to contribute to the species' biological activity potentially. These findings suggest promising avenues for further research and potential applications in pharmacology and natural products, offering new possibilities in the fight against global health issues.

Infusion from Miconia albicans (Melastomataceae) leaves exhibits anti-inflammatory and anti-hyperalgesic activities without toxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Miconia albicans have been extensively used as a traditional medicine to treat inflammation, infection, arthritis, joint pain, and analgesia, which can be purchased easily. Nevertheless, the scientific evidence of chemical profile identification and toxicity investigation is meager. AIM OF THE STUDY: This study aimed to determine the chemical profile of Miconia albicans aqueous extract (MAAE), to investigate its anti-inflammatory and hyperalgesic effects, and toxicity (acute and repeated-dose oral) in vivo studies. MATERIALS AND METHODS: MAAE was obtained by infusion method and its chemical constituents were analyzed and annotated by LC-DAD-MS. The in vivo tests were performed with male and female Swiss mice. Toxicity studies were examined by acute (2000 mg/kg) and repeated-dose oral assays (51.2; 256; 1280 mg/kg); anti-inflammatory evaluation was performed by paw edema and leukocyte migration, and anti-hyperalgesic properties were analyzed by abdominal writhing induced by acetic acid and formalin. The animals were treated by oral means with 51.2, 256, and 1280 mg/kg of MAAE. RESULTS: Twenty-four compounds were annotated from MAAE by LC-DAD-MS, such as ellagitannins, ellagic acid derivatives, flavan-3-ol, and O-glycosylated compounds, including flavonols, triterpenes, and megastigmanes. MAAE induced no significant toxicological effects in the acute and repeated-dose oral assays at lower doses and no histological changes were observed. Hematological and biochemical showed no significant alterations. The oral administration of MAAE 256 mg/kg inhibited the edematogenic effect and reduced the leukocyte migration. In addition, MAAE decreased the abdominal writhings induced by acetic acid and the paw-licking time by formalin assay. CONCLUSION: MAAE showed a significant reduction in inflammatory levels and leukocyte migration, revealing anti-hyperalgesic properties. Additionally, MAAE revealed no acute and repeated-doses toxicities.

Bio-Prospecting of Crude Leaf Extracts from Thirteen Plants of Brazilian Cerrado Biome on Human Glioma Cell Lines.

(1) Background: Malignant gliomas are aggressive tumors characterized by fast cellular growth and highly invasive properties. Despite all biological and clinical advances in therapy, the standard treatment remains essentially palliative. Therefore, searching for alternative therapies that minimize adverse symptoms and improve glioblastoma patients' outcomes is imperative. Natural products represent an essential source in the discovery of such new drugs. Plants from the cerrado biome have been receiving increased attention due to the presence of secondary metabolites with significant therapeutic potential. (2) Aim: This study provides data on the cytotoxic potential of 13 leaf extracts obtained from plants of 5 families (Anacardiaceae, Annonaceae, Fabaceae, Melastomataceae e Siparunaceae) found in the Brazilian cerrado biome on a panel of 5 glioma cell lines and one normal astrocyte. (3) Methods: The effect of crude extracts on cell viability was evaluated by MTS assay. Mass spectrometry (ESI FT-ICR MS) was performed to identify the secondary metabolites classes presented in the crude extracts and partitions. (4) Results: Our results revealed the cytotoxic potential of Melastomataceae species Miconia cuspidata, Miconia albicans, and Miconia chamissois. Additionally, comparing the four partitions obtained from M. chamissois crude extract indicates that the chloroform partition had the greatest cytotoxic activity against the glioma cell lines. The partitions also showed a mean IC50 close to chemotherapy, temozolomide; nevertheless, lower toxicity against normal astrocytes. Analysis of secondary metabolites classes presented in these crude extracts and partitions indicates the presence of phenolic compounds. (5) Conclusions: These findings highlight M. chamissois chloroform partition as a promising component and may guide the search for the development of additional new anticancer therapies.

The evolution of ecological specialization underlies plant endemism in the Atlantic Forest.

BACKGROUND AND AIMS: The evolution of ecological specialization is favoured under divergent selection imposed by increased environmental heterogeneity, although specialization can limit the geographical range of organisms, thus promoting endemism. The Atlantic Forest (AF) is an ancient montane domain with high plant endemism, containing different environments for plant specialization. Miconia is the most diverse genus of woody flowering plant within the AF domain, including AF-endemic and non-endemic lineages. We hypothesized that Miconia species have faced increased environmental heterogeneity and consequently have been selected towards increased specialization in the AF domain, and this increased specialization has greatly reduced species geographical ranges, ultimately promoting endemism. Hence, we made the following predictions: (1) AF-endemic species should face greater environmental heterogeneity than non-endemic species; (2) AF-endemic species should be more specialized than non-endemic species; (3) specialization should lead to smaller geographical ranges; (4) specialization and small geographical ranges among AF-endemic species should conform to a selection-driven evolutionary scenario rather than to a neutral evolutionary scenario; and (5) small geographical ranges among AF-endemic species should date back to the occupation of the AF domain rather than to more recent time periods. METHODS: We used geographical, environmental and phylogenetic data on a major Miconia clade including AF-endemic and non-endemic species. We calculated Rao's Q to estimate the environmental heterogeneity faced by species. We used georeferenced occurrences to estimate the geographical ranges of species. We applied environmental niche modelling to infer species niche breadth. We inferred the most likely evolutionary scenario for species geographical range and niche breadth via a model-fitting approach. We used ancestral reconstructions to evaluate species geographical range throughout time. KEY RESULTS: Atlantic Forest-endemic species faced 33-60 % more environmental heterogeneity, with the increase being associated with montane landscapes in the AF. The AF-endemic species were 60 % more specialized overall, specifically over highly variable environmental gradients in AF montane landscapes. Specialization strongly predicted small geographical ranges among AF-endemic species and was a major range-limiting factor among endemic lineages. The AF-endemic species have evolved towards specialization and small geographical ranges under a selection-driven regime, probably imposed by the great environmental heterogeneity in AF montane landscapes. The AF-endemic species underwent a major reduction of geographical range immediately after their evolution, indicating a long-standing effect of selective pressures in the AF domain. CONCLUSION: Environmental heterogeneity imposes selective pressures favouring ecological specialization and small geographical ranges among plant lineages in the AF domain. This selection-driven process has probably promoted plant endemism in the AF domain throughout its history.

Germination of small tropical seeds has distinct light quality and temperature requirements, depending on microhabitat.

The coexistence of plant species in tropical rainforests is related to specific abiotic resources, varying according to the occurrence microhabitat of each species. Light quality is the main abiotic factor influencing germination of small seeds; however, studies often do not discriminate its effect from that of light irradiance. This study compared specific requirements for seed germination of ten small-seeded species, with restricted occurrence in only one of three contrasting microhabitats: forest understorey, edge of clearings and open areas. Laboratory experiments were carried out to test temperature regime (constant or fluctuating), light quality (R:FR) and light irradiance (PAR), which reproduce high and low conditions commonly found in the microhabitats. Seed germination of all species occurred between 20 and 30 °C, only seeds of open area species were able to germinate at 35 °C and no species required alternating temperatures to germinate. Irrespective of species and microhabitat, a decrease in the R:FR reduced the germination percentage; however, there were differences in the capacity to germinate at low R:FR. The values of R:FR50% were higher for open area and edge species (0.441-0.345) than for understorey species (0.181-0.109), with few exceptions. For all species and most of the tests, germination was not influenced by PAR. Light quality is the most important light signal for germination of small seeds; irradiance has little effect. Our results suggest two distinct patterns of germination for small-seeded species: open area and edge species are light-demanding and require high R:FR to germinate, while understorey species are shade-tolerant and germinate at low R:FR. These differences are responsible for distinct microhabitat occurrence and help to explain the coexistence of species in tropical forests.

Buzz-Pollination in a Tropical Montane Cloud Forest: Compositional Similarity and Plant-Pollinator Interactions.

Buzz-pollinated plants are an essential source of pollen for a significant portion of local bee communities. Buzz pollination research has focused on studying the properties of bee buzzes and their implications on pollen release, morphological specialization of flowers, and the reproductive ecology of buzz-pollinated plants. In contrast, diversity patterns and ecological interactions between bees and buzz-pollinated plants have been studied less. This study analyzed the buzzing bee community of twelve tropical buzz-pollinated co-occurring plant species in a tropical montane cloud forest during the flowering periods of two consecutive years, focusing on diversity, compositional similarity, structure, and specialization (H2´) of the network. Twenty-one bee species belonging to Apidae, Colletidae, and Halictidae were recorded, fifteen species in 2014, and eighteen in 2015. Floral display and visited flowers doubled from first to second year, although the flowering period was 2 months longer in the first year. Bee compositional similarity between plants tended to be low; however, this was due rather to a high nestedness than species replacement. Temporal bee compositional similarity was also low but variable, and different plant species showed the highest similarity between years. The number of bee visits depended significantly on the number of flowers and years. Interactions between bees and plants showed a tendency to generalization. Compared to other buzz-pollinated networks, specialization (H2´) was similar, but diversity was low and the network small. In endangered ecosystems like the Mexican cloud forest, however, buzzing bees support biodiversity and provide an essential ecological service by pollinating dominant understory flora.

Bioprospecting of Natural Compounds from Brazilian Cerrado Biome Plants in Human Cervical Cancer Cell Lines.

Cervical cancer is the third most common in Brazilian women. The chemotherapy used for the treatment of this disease can cause many side effects; then, to overcome this problem, new treatment options are necessary. Natural compounds represent one of the most promising sources for the development of new drugs. In this study, 13 different species of 6 families from the Brazilian Cerrado vegetation biome were screened against human cervical cancer cell lines (CCC). Some of these species were also evaluated in one normal keratinocyte cell line (HaCaT). The effect of crude extracts on cell viability was evaluated by a colorimetric method (MTS assay). Extracts from Annona crassiflora, Miconia albicans, Miconia chamissois, Stryphnodendron adstringens, Tapirira guianensis, Xylopia aromatica, and Achyrocline alata showed half-maximal inhibitory concentration (IC50) values < 30 µg/mL for at least one CCC. A. crassiflora and S. adstringens extracts were selective for CCC. Mass spectrometry (Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (ESI FT-ICR MS)) of A. crassiflora identified fatty acids and flavonols as secondary compounds. One of the A. crassiflora fractions, 7C24 (from chloroform partition), increased H2AX phosphorylation (suggesting DNA damage), PARP cleavage, and cell cycle arrest in CCC. Kaempferol-3-O-rhamnoside and oleic acid were bioactive molecules identified in 7C24 fraction. These findings emphasize the importance of investigating bioactive molecules from natural sources for developing new anti-cancer drugs.

Chemical profile, antioxidant and anti-inflammatory properties of Miconia albicans (Sw.) Triana (Melastomataceae) fruits extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Miconia albicans (Sw.) Triana has been widely used in Brazilian popular medicine for the treatment of several diseases. Aerial parts are used as an infusion to treat arthrosis and arthritis, to relieve rheumatic and stomach pains, and intestinal disorders due to its anti-inflammatory, anti-mutagenic anti-nociceptive, digestive and hepatoprotective properties. AIM OF THE STUDY: This study aimed to characterize the of M. albicans (Sw.) Triana fruits extract (MAFRE) chemical profile and to evaluate its antioxidant, anti-inflammatory and antitumor activities, as well as its toxicity. MATERIALS AND METHODS: Maceration with methanol as liquid extractor was used to prepare MAFRE. M. albicans (Sw.) Triana fruits chemical composition was characterized by UHPLC-QTOF-MS/MS and GC-FID (fatty acid methyl esters composition from lyophilized fruits). MAFRE antioxidant potential was evaluated in vitro using a combination of assays: Folin-Ciocalteu reducing capacity, DPPH• and ABTS radical scavenging ability and ferric reducing antioxidant power (FRAP). In vitro antiproliferative activity was investigated in four human tumor cell lines (U251, 786-0, HT29 and MDA-MB-231) while the effect on the non-tumor cell viability was assessed in the VERO cell line using the on-step MTT assay. In addition, in vivo anti-inflammatory effect was assessed by Croton oil-induced ear edema in mice followed by myeloperoxidase (MPO) activity evaluation. RESULTS: Thirty-five compounds were identified by UHPLC-QTOF-MS/MS. Among it flavonoids derived from quercetin (8), myricetin (1), kaempferol (2), terpenoids (6) and other compounds (18). GC-FID analysis identified and quantified nine fatty acids: palmitic, stearic, arachidic, behenic, elaidic, oleic, eicosenoic, and linoleic acids. The most abundant fatty acids were polyunsaturated fatty acids (5.33 ± 0.17 mg g-1), followed by saturated fatty acids (2.38 ± 0.07 mg g-1) and monounsaturated fatty acids (1.74 ± 0.09 mg g-1). The extract revealed high content of phenolic compounds (43.68 ± 0.50 mg GAE/g of extract), potent antioxidant, and ferrous chelating capacities. Morever, it proved to be non-toxic to the VERO cells, not affecting cells viability (95% of viable cells). No antiproliferative effect against human tumor cell lines were found. Furthermore, MAFRE significantly (p<0.05) reduced ear edema (≈35%) and MPO activity (84.5%) having a statistical effect similar to traditional steroidal and non-steroidal anti-inflammatory drugs. CONCLUSIONS: Taken together, the results evidenced that M. albicans fruit extract has antioxidant properties, a higher concentration of phenolic compounds, flavonoids, fatty acids, and also topical anti-inflammatory activity with low toxicity of extract on VERO cells. Through the ethnomedicinal study, these findings supporting the popular use of M. albicans, but also highlight that not only aerial parts and leaves deserve attention, but the fruits also have anti-inflammatory proprieties and can be a source of phenolic compounds and other substances with potential health benefices.

Antibacterial screening of plants from the Brazilian Atlantic Forest led to the identification of active compounds in Miconia latecrenata (DC.) Naudin.

Antibiotic resistance is a serious global threat to public health. This has promoted the research for new drug targets, and the use of other approaches, such as antimicrobial combined therapy. The present study evaluated the antibacterial activity of 88 extracts from Brazilian Atlantic Forest trees. The organic extract from leaves of Miconia latecrenata (EMl) was the most promising for inhibiting the growth of Staphylococcus aureus (0.3 mg/mL) and Pseudomonas aeruginosa (2.5 mg/mL). After the bioguided fractionation of EMl and metabolite profiling performed by UPLC-DAD-MS/MS, the ethyl acetate (AFMl) and aqueous (WFMl) fractions showed a mixture of phenolic compounds derived from ellagic acid and quercetin. The MIC value of AFMl was two-times lower than EMl for P. aeruginosa, suggesting that these phenolic compounds can perform bioactivity. Furthermore, EMI and AFMl showed synergism with ampicillin and tetracycline for S. aureus and P. aeruginosa, respectively. These findings suggest that extract and fractions of the Miconia latecrenata leaves can be used as therapeutic antibacterial agents.

The role of individual variation in flowering and pollination in the reproductive success of a crepuscular buzz-pollinated plant.

BACKGROUND AND AIMS: Plant individuals within a population differ in their phenology and interactions with pollinators. However, it is still unknown how individual differences affect the reproductive success of plants that have functionally specialized pollination systems. Here, we evaluated whether plant individual specialization in phenology (temporal specialization) and in pollination (pollinator specialization) affect the reproductive success of the crepuscular-bee-pollinated plant Trembleya laniflora (Melastomataceae). METHODS: We quantified flowering activity (amplitude, duration and overlap), plant-pollinator interactions (number of flowers visited by pollinators) and reproductive success (fruit set) of T. laniflora individuals from three distinct locations in rupestrian grasslands of southeastern Brazil. We estimated the degree of individual temporal specialization in flowering phenology and of individual specialization in plant-pollinator interactions, and tested their relationship with plant reproductive success. KEY RESULTS: Trembleya laniflora presented overlapping flowering, a temporal generalization and specialized pollinator interactions. Flowering overlap among individuals and populations was higher than expected by chance but did not affect the individual interactions with pollinators and nor their reproductive success. In contrast, higher individual generalization in the interactions with pollinators was related to higher individual reproductive success. CONCLUSIONS: Our findings suggest that individual generalization in plant-pollinator interaction reduces the potential costs of specialization at the species level, ensuring reproductive success. Altogether, our results highlight the complexity of specialization/generalization of plant-pollinator interactions at distinct levels of organization, from individuals to populations, to species.

The Regulation of Floral Colour Change in Pleroma raddianum (DC.) Gardner.

Floral colour change is a widespread phenomenon in angiosperms, but poorly understood from the genetic and chemical point of view. This article investigates this phenomenon in Pleroma raddianum, a Brazilian endemic species whose flowers change from white to purple. To this end, flavonoid compounds and their biosynthetic gene expression were profiled. By using accurate techniques (Ultra Performance Liquid Chromatography-High-Resolution Mass Spectrometry (UPLC-HRMS)), thirty phenolic compounds were quantified. Five key genes of the flavonoid biosynthetic pathway were partially cloned, sequenced, and the mRNA levels were analysed (RT-qPCR) during flower development. Primary metabolism was also investigated by gas chromatography coupled to mass spectrometry (GC-EIMS), where carbohydrates and organic acids were identified. Collectively, the obtained results suggest that the flower colour change in P. raddianum is determined by petunidin and malvidin whose accumulation coincides with the transcriptional upregulation of early and late biosynthetic genes of the flavonoid pathway, mainly CHS and ANS, respectively. An alteration in sugars, organic acids and phenolic co-pigments is observed together with the colour change. Additionally, an increment in the content of Fe3+ ions in the petals, from the pink to purple stage, seemed to influence the saturation of the colour.

Apoplast-symplast compartmentalization and functional traits of iron and aluminum in promeristematic tissues of nematode induced galls on Miconia spp.

The nutritive tissues of galls induced by Ditylenchus gallaeformans (Nematoda) have promeristematic capacity, which may turn these galls into sinks of Al on their Melastomataceae Al-accumulating hosts. Such a sink of Al may affect gall growth and mineral nutrient intake. Based on the fact that galls are good models for plant developmental studies, we aimed to understand how Al-accumulating host plants in the Cerrado environment deal with Al toxicity in subcellular levels. Here, we used the ICP-OES method to check the variations on mineral nutrients, and the morin, hematoxylin, and Prussian blue stainings for Al and Fe histolocalization in galls induced on four Miconia species of the Brazilian Cerrado. We confirmed the new Al-accumulating feature for two Miconia species of the Cerrado environment. Furthermore, we found that Al accumulates in lesser concentrations in gall tissues than in non-galled tissues of the Miconia hosts. Staining methods indicated that the polyphenols avoid Al-binding to the apoplast and the nucleolus of the promeristematic cells, and mediated its binding to parenchyma cell walls. As well, we inferred that Fe3+ is transported by xylem and stored in gall parenchyma, where it is reduced to Fe2+, being available in gall nutritive cells. Our results demonstrated an Al compartmentalization between the apoplast and symplast of the inner cell layers in galls, as well as indicated the phenolics action against Al-toxicity and toward Fe availability for the diet of Ditylenchus gallaeformans.

Matteucinol, isolated from Miconia chamissois, induces apoptosis in human glioblastoma lines via the intrinsic pathway and inhibits angiogenesis and tumor growth in vivo.

Gliomas account for nearly 70% of the central nervous system tumors and present a median survival of approximately 12-17 months. Studies have shown that administration of novel natural antineoplastic agents is been highly effective for treating gliomas. This study was conducted to investigate the antitumor potential (in vitro and in vivo) of Miconia chamissois Naudin for treating glioblastomas. We investigated the cytotoxicity of the chloroform partition and its sub-fraction in glioblastoma cell lines (GAMG and U251MG) and one normal cell line of astrocytes. The fraction showed cytotoxicity and was selective for tumor cells. Characterization of this fraction revealed a single compound, Matteucinol, which was first identified in the species M. chamissois. Matteucinol promoted cell death via intrinsic apoptosis in the adult glioblastoma lines. In addition, Matteucinol significantly reduced the migration, invasion, and clonogenicity of the tumor cells. Notably, it also reduced tumor growth and angiogenesis in vivo. Moreover, this agent showed synergistic effects with temozolomide, a chemotherapeutic agent commonly used in clinical practice. Our study demonstrates that Matteucinol from M chamissois is a promising compound for the treatment of glioblastomas and may be used along with the existing chemotherapeutic agents for more effective treatment.

Systematics and relationships of Tryssophyton (Melastomataceae), with a second species from the Pakaraima Mountains of Guyana.

The systematics of Tryssophyton, herbs endemic to the Pakaraima Mountains of western Guyana, is reviewed and Tryssophyton quadrifolius K.Wurdack & Michelang., sp. nov. from the summit of Kamakusa Mountain is described as the second species in the genus. The new species is distinguished from its closest relative, Tryssophyton merumense, by striking vegetative differences, including number of leaves per stem and leaf architecture. A phylogenetic analysis of sequence data from three plastid loci and Melastomataceae-wide taxon sampling is presented. The two species of Tryssophyton are recovered as monophyletic and associated with mostly Old World tribe Sonerileae. Fruit, seed and leaf morphology are described for the first time, biogeography is discussed and both species are illustrated.

Foliar water-uptake strategies are related to leaf water status and gas exchange in plants from a ferruginous rupestrian field.

PREMISE: Fog is a frequent event in Brazilian rupestrian field and plays an important role in the physiology of several plant species. Foliar water uptake (FWU) of fog may be fast or slow depending on the species. However, fog water may negatively affect CO2 assimilation. Thus, the interference in the water and carbon balance as a result of different strategies of FWU was evaluated to verify whether fog may mitigate possible water deficit in leaves. METHODS: Four plant species with different FWU strategies were studied in a ferruginous rupestrian field with frequent fog. Gas exchange and water potential were measured before dawn and at midday during the dry and rainy seasons, separating foggy from non-foggy days during the dry season. RESULTS: The FWU speed negatively influences CO2 assimilation in the dry season, possibly because of its negative relationship with stomatal conductance, since reduced stomatal aperture impairs carbon entrance. Fog presence increased leaf water potential both in early morning and midday during the dry season. However, during the rainy season, the values of leaf water potential were lower at midday, than during the dry season with fog at midday, which favors leaf gas exchanges. CONCLUSIONS: FWU interferes negatively, but briefly with CO2 assimilation. Nevertheless, FWU prevents water loss through transpiration and increases the water status of plants in the dry season. That is, FWU results in a compensation between CO2 assimilation and foliar hydration, which, in fact, is beneficial to the plants of this ecosystem.

Hydrolysable Tannins and Biological Activities of Meriania hernandoi and Meriania nobilis (Melastomataceae).

A bio-guided study of leaf extracts allowed the isolation of two new macrobicyclic hydrolysable tannins, namely merianin A (1) and merianin B (2), and oct-1-en-3-yl ß-xylopyranosyl-(1"-6')-ß-glucopyranoside (3) from Meriania hernandoi, in addition to 11 known compounds reported for the first time in the Meriania genus. The structures were elucidated by spectroscopic analyses including one- and two-dimensional NMR techniques and mass spectrometry. The bioactivities of the compounds were determined by measuring the DPPH radical scavenging activity and by carrying out antioxidant power assays (FRAP), etiolated wheat coleoptile assays and phytotoxicity assays on the standard target species Lycopersicum esculentum W. (tomato). Compounds 1 and 2 exhibited the best free radical scavenging activities, with FRS50 values of 2.0 and 1.9 µM, respectively.

Acylated Flavonoid Glycosides are the Main Pigments that Determine the Flower Colour of the Brazilian Native Tree Tibouchina pulchra (Cham.) Cogn.

Tibouchina pulchra (Cham.) Cogn. is a plant native to Brazil whose genus and family (Melastomataceae) are poorly studied with regards to its metabolite profile. Phenolic pigments of pink flowers were studied by ultra-performance liquid chromatography with a photodiode array detector and electrospray ionization quadrupole time-of-flight mass spectrometry. Therein, twenty-three flavonoids were identified with eight flavonols isolated by preparative high-performance liquid chromatography and analysed by one- and two-dimensional nuclear magnetic resonance. Kaempferol derivatives were the main flavonols, encompassing almost half of the detected compounds with different substitution patterns, such as glucoside, pentosides, galloyl-glucoside, p-coumaroyl-glucoside, and glucuronide. Concerning the anthocyanins, petunidin p-coumaroyl-hexoside acetylpentoside and malvidin p-coumaroyl-hexoside acetylpentoside were identified and agreed with previous reports on acylated anthocyanins from Melastomataceae. A new kaempferol glucoside was identified as kaempferol-(2''-O-methyl)-4'-O-α-d-glucopyranoside. Moreover, twelve compounds were described for the first time in the genus with five being new to the family, contributing to the chemical characterisation of these taxa.

Anti-inflammatory and antinociceptive activities of the leaf methanol extract of Miconia minutiflora (Bonpl.) DC. and characterization of compounds by UPLC-DAD-QTOF-MS/MS.

Some species of the genus Miconia are used in Brazilian folk medicine as analgesic and anti-inflammatory; however, several species of this genus are still poorly studied. Therefore, the aims of this study were to investigate the phytochemistry characterization by UPLC-DAD-QTOF-MS/MS, acute toxicity, anti-inflammatory and antinociceptive properties of Miconia minutiflora (Bonpl.) DC. The methanol extract of M. minutiflora (Mm-MeOH) was subjected to ultra-high-performance liquid chromatography (UPLC-DAD-QTOF-MS/MS) for the identification of the main phytocompounds. The anti-inflammatory properties of the extracts were studied using several inflammation models induced by carrageenan and acetic acid-induced vascular permeability. Antinociceptive effects of Mm-MeOH were assessed in nociception induced by intraperitoneal acetic acid or subplantar formalin injection. The role of α-adrenergic, cholinergic, and opioid receptors in modulating the extract's antinociceptive activity was determined. Analyses by UPLC-DAD-QTOF-MS/MS revealed the presence of ellagic acid, gallotannin, and terpenes in the methanol extract. Mm-MeOH (100 mg/kg) reduced carrageenan-induced paw edema and vascular permeability and inhibited leukocyte migration toward the air pouch and pleural cavity. Furthermore, Mm-MeOH decreased tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) levels. Administration of Mm-MeOH reduced the number of writhes by 58.9% and increased the pain threshold in the formalin test. The anti-inflammatory action mechanism of Mm-MeOH is associated with inhibition of proinflammatory cytokines TNF-α and IL-1ß, whereas the antinociceptive actions involve peripheral and central mechanisms with participation of α2-adrenergic receptors. These effects may be attributed to the presence of polyphenolics in the extract.

Evaluation of the chemical composition and variability of the volatile oils from Trembleya parviflora leaves

Abstract Trembleya parviflora (D. Don) Cogn., Melastomataceae, also known as "quaresmeira-branca", is a subshrub that is commonly used to treat verminosis, scabies, dermatoses, rheumatism, vaginal infections, ulcerations and wounds. The aim of this work was to perform a morphological study of T. parviflora, evaluate the composition and chemical variability of the volatile oils from the leaves, perform phytochemical screening of the powder from the leaves and to define parameters for quality control of the plant material. Macroscopic characterization of T. parviflora was carried out by naked eye in Serra dos Pireneus, Pirenópolis, Goiás for 12 months. Volatile oils were subjected to hydrodistillation with Clevenger apparatus and analyzed by gas chromatography-mass spectrometry. Phytochemical screening and ash and volatile compound content determination were performed by conventional techniques. T. parviflora has simple, oppositely crossed and petiolate leaves. The inflorescence of this plant is a cyme. The presence of coumarins, steroids, triterpenes, flavonoids and tannins was observed. The total ash content was 4.05 ± 0.02%; the insoluble ash content was 0.10 ± 0.03%; and the volatile compound content was 9.53 ± 0.02%. The major compounds present in the volatile oils were α-terpineol (2.7-16.5%), α-pinene (0.6-25.4%), β-pinene (2.7-23.1%), sabinene (1.2-14.1%), acetoxyeudesman-4-α-ol (0.6-6.3%) and 2,4a-8,8-tetramethyldecahydrocyclopropanaphtalene (2.4-24.4). Two clusters were identified: Cluster I represented the period with low levels of rainfall, and Cluster II represented the period with high levels of rainfall. This study provides data that can be applied for the quality control of powdered leaves and is the first description of the chemical composition and variability of the volatile oils from the leaves of T. parviflora.