Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 336
Filtrar
Más filtros

Intervalo de año de publicación
1.
New Phytol ; 242(5): 2322-2337, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38634161

RESUMEN

Shifts among functional pollinator groups are commonly regarded as sources of floral morphological diversity (disparity) through the formation of distinct pollination syndromes. While pollination syndromes may be used for predicting pollinators, their predictive accuracy remains debated, and they are rarely used to test whether floral disparity is indeed associated with pollinator shifts. We apply classification models trained and validated on 44 functional floral traits across 252 species with empirical pollinator observations and then use the validated models to predict pollinators for 159 species lacking observations. In addition, we employ multivariate statistics and phylogenetic comparative analyses to test whether pollinator shifts are the main source of floral disparity in Melastomataceae. We find strong support for four well-differentiated pollination syndromes ('buzz-bee', 'nectar-foraging vertebrate', 'food-body-foraging vertebrate', 'generalist'). While pollinator shifts add significantly to floral disparity, we find that the most species-rich 'buzz-bee' pollination syndrome is most disparate, indicating that high floral disparity may evolve without pollinator shifts. Also, relatively species-poor clades and geographic areas contributed substantially to total disparity. Finally, our results show that machine-learning approaches are a powerful tool for evaluating the predictive accuracy of the pollination syndrome concept as well as for predicting pollinators where observations are missing.


Asunto(s)
Flores , Melastomataceae , Polinización , Polinización/fisiología , Flores/fisiología , Flores/anatomía & histología , Melastomataceae/fisiología , Abejas/fisiología , Animales , Filogenia , Especificidad de la Especie , Modelos Biológicos
2.
Chem Biodivers ; 21(7): e202400680, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38748618

RESUMEN

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.


Asunto(s)
Antibacterianos , Antifúngicos , Antioxidantes , Hipoglucemiantes , Melastomataceae , Pruebas de Sensibilidad Microbiana , Extractos Vegetales , Hojas de la Planta , Hojas de la Planta/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Extractos Vegetales/aislamiento & purificación , Melastomataceae/química , Antioxidantes/farmacología , Antioxidantes/química , Antioxidantes/aislamiento & purificación , Antifúngicos/farmacología , Antifúngicos/química , Antifúngicos/aislamiento & purificación , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Hipoglucemiantes/farmacología , Hipoglucemiantes/química , Hipoglucemiantes/aislamiento & purificación , Candida/efectos de los fármacos , alfa-Amilasas/antagonistas & inhibidores , alfa-Amilasas/metabolismo , Flavonoides/química , Flavonoides/farmacología , Flavonoides/aislamiento & purificación , Cromatografía Líquida de Alta Presión
3.
Int J Mol Sci ; 25(2)2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38255880

RESUMEN

Auxin Response Factors (ARFs) mediate auxin signaling and govern diverse biological processes. However, a comprehensive analysis of the ARF gene family and identification of their key regulatory functions have not been conducted in Melastoma dodecandrum, leading to a weak understanding of further use and development for this functional shrub. In this study, we successfully identified a total of 27 members of the ARF gene family in M. dodecandrum and classified them into Class I-III. Class II-III showed more significant gene duplication than Class I, especially for MedARF16s. According to the prediction of cis-regulatory elements, the AP2/ERF, BHLH, and bZIP transcription factor families may serve as regulatory factors controlling the transcriptional pre-initiation expression of MedARF. Analysis of miRNA editing sites reveals that miR160 may play a regulatory role in the post-transcriptional expression of MeARF. Expression profiles revealed that more than half of the MedARFs exhibited high expression levels in the stem compared to other organs. While there are some specific genes expressed only in flowers, it is noteworthy that MedARF16s, MedARF7A, and MedARF9B, which are highly expressed in stems, also demonstrate high expressions in other organs of M. dodecandrum. Further hormone treatment experiments revealed that these MedARFs were sensitive to auxin changes, with MedARF6C and MedARF7A showing significant and rapid changes in expression upon increasing exogenous auxin. In brief, our findings suggest a crucial role in regulating plant growth and development in M. dodecandrum by responding to changes in auxin. These results can provide a theoretical basis for future molecular breeding in Myrtaceae.


Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico , Melastomataceae , Barajamiento de ADN , Flores , Duplicación de Gen , Ácidos Indolacéticos/farmacología
4.
Am J Bot ; 110(6): e16183, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37276141

RESUMEN

PREMISE: Floral shape (relative arrangement and position of floral organs) is critical in mediating fit with pollinators and maximizing conspecific pollen transfer particularly in functionally specialized systems. To date, however, few studies have attempted to quantify flowers as the inherently three-dimensional (3D) structures they are and determine the effect of intraspecific shape variation on pollen transfer. We here addressed this research gap using a functionally specialized system, buzz pollination, in which bees extract pollen through vibrations, as a model. Our study species, Meriania hernandoi (Melastomataceae), undergoes a floral shape change from pseudocampanulate corollas with more actinomorphically arranged stamens (first day) to open corollas with a more zygomorphic androecium (second day) over anthesis, providing a natural experiment to test how variation in floral shape affects pollination performance. METHODS: In one population of M. hernandoi, we bagged 51 pre-anthetic flowers and exposed half of them to bee pollinators when they were in either stage of their shape transition. We then collected flowers, obtained 3D flower models through x-ray computed tomography for 3D geometric morphometric analyses, and counted the pollen grains remaining per stamen (male pollination performance) and stigmatic pollen loads (female pollination performance). RESULTS: Male pollination performance was significantly higher in open flowers with zygomorphic androecia than in pseudo-campanulate flowers. Female pollination performance did not differ among floral shapes. CONCLUSIONS: These results suggest that there is an "optimal" shape for male pollination performance, while the movement of bees around the flower when buzzing the spread-out stamens results in sufficient pollen deposition regardless of floral shape.


Asunto(s)
Melastomataceae , Abejas , Animales , Flores , Polinización , Polen , Lagunas en las Evidencias
5.
Int J Mol Sci ; 24(2)2023 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-36674776

RESUMEN

Growth-regulating factor (GRF) is a kind of transcription factor unique to plants, playing an important role in the flowering regulation, growth, and development of plants. Melastoma dodecandrum is an important member of Melastomataceae, with ornamental, medicinal, and edible benefits. The identification of the GRF gene family in M. dodecandrum can help to improve their character of flavor and continuous flowering. The members of the GRF gene family were identified from the M. dodecandrum genome, and their bioinformatics, selective pressure, and expression patterns were analyzed. The results showed that there were 20 GRF genes in M. dodecandrum. Phylogenetic analysis showed that the 71 GRF genes from M. dodecandrum, Arabidopsis thaliana, Camellia sinensis, and Oryza sativa can be divided into three clades and six subclades. The 20 GRF genes of M. dodecandrum were distributed in twelve chromosomes and one contig. Furthermore, the gene structure and motif analysis showed that the intron and motif within each clade were very similar, but there were great differences among different clades. The promoter contained cis-acting elements related to hormone induction, stress, and growth and development. Different transcriptomic expression of MdGRFs indicated that MdGRFs may be involved in regulating the growth and development of M. dodecandrum. The results laid a foundation for further study on the function and molecular mechanism of the M. dodecandrum GRF gene family.


Asunto(s)
Melastomataceae , Melastomataceae/química , Filogenia , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Familia de Multigenes , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
6.
Molecules ; 28(3)2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36771057

RESUMEN

(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.


Asunto(s)
Antineoplásicos , Glioma , Melastomataceae , Humanos , Brasil , Cloroformo , Línea Celular , Antineoplásicos/farmacología , Extractos Vegetales/farmacología , Melastomataceae/química , Glioma/tratamiento farmacológico , Ecosistema
7.
Mol Phylogenet Evol ; 171: 107461, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35351631

RESUMEN

Miconia is among the largest plant genera in the Neotropics and a taxonomically complex lineage. Indeed, molecular phylogenetic data shows that none of its traditionally accepted sections are monophyletic, preventing taxonomic advances within the genus. Miconia is the largest plant genus in the Brazilian Atlantic Forest, including three main lineages, the Leandra s.s. clade (ca. 215 spp.), the Miconia sect. Chaenanthera (24 spp.), and the Miconia discolor clade (estimated 77 spp.). Out of these lineages, the Miconia discolor clade is the only currently lacking phylogenetic data, complicating its taxonomy. In this study, we reconstruct the phylogeny of the Miconia discolor clade, using three plastid (atpF-H, psbK-I, and psaI-accD) and two nuclear (ETS and ITS) markers. We sampled 60 out of the 77 species of the group, representing 78% of its diversity. Taxa were selected considering their distribution, morphology, and previous phylogenetic knowledge. We used the newly reconstructed phylogeny to better understand phylogenetic relationships among Atlantic Forest species and morphologically similar taxa, and to propose a new infrageneric classification for the Miconia discolor clade: the Miconia supersection Discolores. We further studied the evolution of seven morphological characters using a Maximum Likelihood approach, and estimated the ancestral range distribution of various lineages in order to understand the biogeographic history of this clade. We found that dichasial inflorescences represent the ancestral condition within Miconia, subsequently giving rise to scorpioid and glomerulate inflorescences in the studied group. We describe Miconia supersect. Discolores, originated in the Amazon region, which is recognized by a dense layer of branched tricomes covering young branches and non-dichasial inflorescences, including three main lineages: (i) Miconia sect. Albicantes, characterized by persistent bracts and arachnoid indument on the abaxial surface of leaves, mainly distributed in the Amazon basin; (ii) Miconia sect. Discolores, characterized by caducous calyx lobes and glomerulate inflorescences, centered in the Atlantic Forest; and (iii) Miconia sect. Multispicatae, characterized by leaves not completely covered with indument, and capitate stigma, mainly distributed in the Atlantic Forest. All three sections and the supersection originated in the Neogene, between the Late Miocene and the Early Pliocene.


Asunto(s)
Melastomataceae , Teorema de Bayes , Bosques , Funciones de Verosimilitud , Melastomataceae/anatomía & histología , Filogenia
8.
Mol Phylogenet Evol ; 175: 107581, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35810973

RESUMEN

Sonerileae is a diverse Melastomataceae lineage comprising ca. 1000 species in 44 genera, with >70% of genera and species distributed in Asia. Asian Sonerileae are taxonomically intractable with obscure generic circumscriptions. The backbone phylogeny of this group remains poorly resolved, possibly due to complexity caused by rapid species radiation in early and middle Miocene, which hampers further systematic study. Here, we used genome resequencing data to reconstruct the phylogeny of Asian Sonerileae. Three parallel datasets, viz. single-copy ortholog (SCO), genomic SNPs, and whole plastome, were assembled from genome resequencing data of 205 species for this purpose. Based on these genome-scale data, we provided the first well resolved phylogeny of Asian Sonerileae, with 34 major clades identified and 74% of the interclade relationships consistently resolved by both SCO and genomic data. Meanwhile, widespread phylogenetic discordance was detected among SCO gene trees as well as species trees reconstructed using different tree estimation methods (concatenation/site-based coalescent method/summary method) or different datasets (SCO/genomic/plastome). We explored sources of discordance using multiple approaches and found that the observed discordance in Asian Sonerileae was mainly caused by a combination of biased distribution of missing data, random noise from uninformative genes, incomplete lineage sorting, and hybridization/introgression. Exploration of these sources can enable us to generate hypotheses for future testing, which is the first step towards understanding the evolution of Asian Sonerileae. We also detected high levels of homoplasy for some characters traditionally used in taxonomy, which explains current chaotic generic delimitations. The backbone phylogeny of Asian Sonerileae revealed in this study offers a solid basis for future taxonomic revision at the generic level.


Asunto(s)
Melastomataceae , Genómica/métodos , Hibridación Genética , Filogenia , Análisis de Secuencia de ADN
9.
Phytopathology ; 112(4): 881-887, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34495679

RESUMEN

Ditylenchus gallaeformans is a plant parasitic nematode that induces galls on aboveground parts of Melastomataceae plants. It differs from most gall-inducing nematodes in that it is not an endoparasite and has been considered as a possible biological control agent against invasive species of Miconia. Little is known about D. gallaeformans biology, genetic differences among populations, and host preferences. This study examined the genetic differences among D. gallaeformans populations from different locations and host species and the phylogenetic relationships among them. Nematodes were collected from galls in plants from Costa Rica, Dominica, and Trinidad. The Cytochrome c oxidase 1 (cox1) region was sequenced from a total of 33 individual nematodes isolated from 33 different plant individuals, representing 21 species of Melastomataceae. Phylogenetic reconstructions, haplotype networks, and analysis of molecular variance showed that the species is monophyletic and has three major clades, which were mostly consistent with geographic location but not with host species. The first clade was composed by two subclades, one with individuals from Costa Rica and one with individuals from Dominica. The second and third clades comprised nematodes only from Trinidad. Overall, there is no evidence of host-species specialization in D. gallaeformans. Biocontrol efforts using the nematode against invasive Miconia could focus on geographical location matching but likely will not need to match host species.


Asunto(s)
Melastomataceae , Nematodos , Tylenchida , Animales , Genética de Población , Melastomataceae/parasitología , Nematodos/genética , Filogenia , Enfermedades de las Plantas , Hojas de la Planta/parasitología , Plantas/parasitología
10.
J Plant Res ; 135(2): 259-274, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34997369

RESUMEN

This study aimed to describe the origin, position, development and typology of inflorescences in Miconieae through ontogenetic and morphological analyses using light microscopy. We observed three morphological character states: terminal, pseudo-axillary and axillary; and two ontogenetic states: terminal and axillary. The terminal and pseudoaxillary inflorescences originate from terminal reproductive meristems. Pseudoaxillary inflorescences result from unequal development of vegetative meristems which flank the terminal flowering unit, whereas in terminal inflorescences, both vegetative meristems develop equally. In axillary inflorescences, the terminal reproductive meristem is not involved, while axillary inflorescences originate from reproductive axillary meristems. The inflorescences range from heterocladic and thyrsoid to simpler types, such as botryoid and triad. Such characteristics can also be seen in paracladia, particularly those most distal. The terminal inflorescence is observed in all clades of Miconieae, and pseudoaxillary and axillary inflorescences should be apomorphic states in the tribe and derived from the terminal condition.


Asunto(s)
Inflorescencia , Melastomataceae , Evolución Biológica , Meristema
11.
J Plant Res ; 135(5): 659-680, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35802292

RESUMEN

The androecium of Melastomataceae presents notable modifications in its merosity, morphology between whorls and in prolonged connectives and appendages. We carried out a comparative study of six Melastomataceae species to shed light on the developmental processes that originate such stamen diversity. The development of stamens was studied using scanning electron microscopy and histological observations. The stamens of all species studied have a curved shape because they emerge on a plane displaced by the perigynous hypanthium. They are the last flower organs to initiate and therefore their growth is inwards and towards the floral center. Despite the temporal inversion between carpels and stamens in Melastomataceae, the androecium maintains the centripetal pattern of development, the antepetalous stamens emerging after antesepalous stamens. The isomerous androecium can be the result of abortion of the antepetalous stamens, whereas heterostemony seems to be caused by differences in position and the stamen development time. Pedoconnectives and ventral appendages originate from the basal expansion of the anther late in floral development. The delay in stamen development may be a consequence of their dependence on the formation of a previous space so that they can grow. Most of the stamen diversity is explained by the formation of the connectives and their appendages. The formation of a basal-ventral anther prolongation, which culminates in the development of the pedoconnective, does not differ from other types of sectorial growth of the connective, which form shorter structures.


Asunto(s)
Melastomataceae , Flores/anatomía & histología , Melastomataceae/anatomía & histología , Microscopía Electrónica de Rastreo
12.
An Acad Bras Cienc ; 94(4): e20210190, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36228216

RESUMEN

Duchenne muscular dystrophy (DMD) is a severe disease with no cure caused by a genetic abnormality, promoting progressive muscle degeneration. Corticosteroids are used drugs in treatment associated with adverse effects. The extract of Miconia ferruginata (Melastomataceae) (MF) has demonstrated potent antioxidant and anti-inflammatory potential in vitro. This study used a DMD model (mdx) to determine the toxic dose of this plant and found a possible non-toxic dose with therapeutic effects. The mdx groups received an intraperitoneal injection of 0 (control group), 50, 100, 200, 300, and 2000 mg kg-1 of the aqueous leaf extract following a single-dose acute toxicity protocol and were observed for 14 days. The range of toxicity of the extract and LD50 were determined. Histopathological analysis, the quantification of fibrosis, and immunohistochemical analysis of the tissues were performed. The results demonstrated that 2000 mg kg-1 was highly toxic, inducing histopathological changes in the tissues evaluated, with 100% mortality in 48 hours. The other doses caused no behavioral changes or signs of toxicity. The MF extract led reduction in histopathological changes, fibrosis, and inflammation, a reduction in HSP70 and an increase in MCL-1 proteins. Doses of 50-200 mg kg-1 demonstrated regenerative tissue and anti-inflammatory potential.


Asunto(s)
Melastomataceae , Distrofia Muscular de Duchenne , Animales , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Antioxidantes/metabolismo , Modelos Animales de Enfermedad , Fibrosis , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos mdx , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/tratamiento farmacológico , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/metabolismo , Proteína 1 de la Secuencia de Leucemia de Células Mieloides/uso terapéutico , Extractos Vegetales/metabolismo , Extractos Vegetales/uso terapéutico , Extractos Vegetales/toxicidad
13.
Molecules ; 27(5)2022 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-35268622

RESUMEN

The roots of Melastoma malabathricum subsp. normale (D. Don) Karst. Mey have been used in traditional ethnic medicine systems in China to treat inflammation-triggered ailments, such as trauma, toothache, and fever. Therefore, the aim of this study is to screen for compounds with anti-inflammatory activity in the title plant. The extract of M. malabathricum subsp. normale roots was separated using various chromatographic methods, such as silica gel, ODS C18, MCI gel, and Sephadex LH-20 column chromatography, as well as semi-preparative HPLC. One new complex tannin, named whiskey tannin D (1), and an undescribed tetracyclic depsidone derivative, named guanxidone B (2), along with nine known polyphenols (2-10) and three known depsidone derivatives (12-14) were obtained from this plant. The structures of all compounds were elucidated by extensive NMR and CD experiments in conjunction with HR-ESI-MS data. All these compounds were isolated from this plant for the first time. Moreover, compounds 1-4, 8, and 10-14 were obtained for the first time from the genus Melastoma, and compounds 1, 2, and 11-14 have not been reported from the family Melastomataceae. This is the first report of complex tannin and depsidone derivatives from M. malabathricum subsp. normale, indicating their chemotaxonomic significance to this plant. Compounds 1-12 were investigated for their anti-inflammatory activities on the production of the nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and compounds 1, 11, and 12 showed anti-inflammatory activities with IC50 values of 6.46 ± 0.23 µM, 8.02 ± 0.35 µM, and 9.82 ± 0.43 µM, respectively. The structure-activity relationship showed that the catechin at glucose C-1 in ellagitannin was the key to its anti-inflammatory activity, while CH3O- at C-16 of aromatic ring A in depsidone derivatives had little effect on its anti-inflammatory activity. The study of structure-activity relationships is helpful to quickly discover new anti-inflammatory drugs. The successful isolation and structure identification of these compounds, especially complex tannin 1, not only provide materials for the screening of anti-inflammatory compounds, but also provide a basis for the study of chemical taxonomy of the genus Melastoma.


Asunto(s)
Melastomataceae , Antiinflamatorios/química , Antiinflamatorios/farmacología , Depsidos , Lactonas , Melastomataceae/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Polifenoles/farmacología
14.
Molecules ; 27(6)2022 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-35335366

RESUMEN

Chemical composition of the essential oils and extracts and the antimicrobial activity of Miconia minutiflora were investigated. The flavanone glycosides, pinocembroside and pinocembrin-7-O-[4″,6″-HHDP]-ß-D-glucose, were identified, along with other compounds that belong mainly to the triterpene class, besides the phenolics, gallic acid and methyl gallate. Sesquiterpenes and monoterpenes were the major compounds identified from the essential oils. Screening for antimicrobial activity from the methanolic extract of the leaves showed that the MIC and MMC values against the tested microorganisms ranged from 0.625 to 5 mg·mL−1 and that the extract was active against microorganisms, Staphyloccocus aureus, Escherichia coli, and Bacillus cereus.


Asunto(s)
Antiinfecciosos , Flavanonas , Melastomataceae , Triterpenos , Antiinfecciosos/química , Antiinfecciosos/farmacología , Flavanonas/farmacología , Glicósidos/farmacología , Melastomataceae/química
15.
Molecules ; 27(3)2022 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-35164385

RESUMEN

Miconia chamissois Naudin is a species from the Cerrado, which is being increasingly researched for its therapeutic potential. The aim of this study was to obtain a standardized extract and to evaluate seasonal chemical variations. Seven batches of aqueous extracts from leaves were produced for the standardization. These extracts were evaluated for total solids, polyphenol (TPC) and flavonoid content (TFC), vitexin derivative content, antioxidant activity; thin-layer chromatography (TLC), and high-performance liquid chromatography (HPLC) profiles were generated. For the seasonal study, leaves were collected from five different periods (May 2017 to August 2018). The results were correlated with meteorological data (global radiation, temperature, and rainfall index). Using chromatographic and spectroscopic techniques, apigenin C-glycosides (vitexin/isovitexin) and derivatives, luteolin C-glycosides (orientin/isoorientin) and derivatives, a quercetin glycoside, miconioside B, matteucinol-7-O-ß-apiofuranosyl (1 → 6) -ß-glucopyranoside, and farrerol were identified. Quality parameters, including chemical marker quantification by HPLC, and biological activity, are described. In the extract standardization process, all the evaluated parameters showed low variability. The seasonality study revealed no significant correlations (p < 0.05) between TPC or TFC content and meteorological data. These results showed that it is possible to obtain extracts from M. chamissois at any time of the year without significant differences in composition.


Asunto(s)
Melastomataceae/química , Extractos Vegetales/química , Hojas de la Planta/química , Flavonoides/análisis , Pradera , Polifenoles/análisis , Estaciones del Año
16.
Molecules ; 27(17)2022 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-36080124

RESUMEN

Weeds pose a problem, infesting areas and imposing competition and harvesting difficulties in agricultural systems. Studies that provide the use of alternative methods for weed control, in order to minimize negative impacts on the environment, have intensified. Native flora represents a source of unexplored metabolites with multiple applications, such as bioherbicides. Therefore, we aimed to carry out a preliminary phytochemical analysis of crude extracts and fractions of Miconia auricoma and M. ligustroides and to evaluate these and the isolated metabolites phytotoxicity on the growth of the target species. The growth bioassays were conducted with Petri dishes with lettuce, morning glory, and sourgrass seeds incubated in germination chambers. Phytochemical analysis revealed the presence of flavonoids, isolated myricetin, and a mixture of quercetin and myricetin. The results showed that seedling growth was affected in a dose-dependent manner, with the root most affected and the seedlings of the lettuce, morning glory, and sourgrass as the most sensitive species, respectively. Chloroform fractions and myricetin were the most inhibitory bioassays evaluated. The seedlings showed structural changes, such as yellowing, nonexpanded cotyledons, and less branched roots. These results indicate the phytotoxic potential of Miconia allelochemicals, since there was the appearance of abnormal seedlings and growth reduction.


Asunto(s)
Melastomataceae , Germinación , Lactuca , Fitoquímicos/farmacología , Extractos Vegetales/química , Extractos Vegetales/farmacología , Malezas , Plantones , Control de Malezas
17.
Molecules ; 27(13)2022 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-35807377

RESUMEN

Species of the genus Miconia are used in traditional medicine for the treatment of diseases, such as pain, throat infections, fever, and cold, and they used as depuratives, diuretics, and sedatives. This work reviewed studies carried out with Miconia species, highlighting its ethnomedicinal uses and pharmacological and phytochemical potential. This information was collected in the main platforms of scientific research (PubMed, Scopus, and Web of Science). Our findings show that some of the traditional uses of Miconia are corroborated by biological and/or pharmacological assays, which demonstrated, among other properties, anti-inflammatory, analgesic, antimutagenic, antiparasitic, antioxidant, cytotoxic, and antimicrobial activities. A total of 148 chemical compounds were identified in Miconia species, with phenolic compounds being the main constituents found in the species of this genus. Such phytochemical investigations have demonstrated the potential of species belonging to this genus as a source of bioactive substances, thus reinforcing their medicinal and pharmacological importance.


Asunto(s)
Melastomataceae , Etnofarmacología , Medicina Tradicional , Fitoquímicos/química , Fitoquímicos/farmacología , Fitoquímicos/uso terapéutico , Fitoterapia , Extractos Vegetales/química , Extractos Vegetales/farmacología
18.
Molecules ; 27(18)2022 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-36144693

RESUMEN

The plant Miconia albicans (Sw.) Triana has been popularly used in Brazil to treat chronic inflammatory disturbances, such as osteoarthritis. This disease affects 250 million people worldwide, and is associated with intense pain and loss of articular function. There is a lack of information about the phytochemistry and bioactivity of M. albicans. Therefore, this study determined the chemical composition of some extracts and evaluated their cytotoxicity, along with their antioxidant and anti-inflammatory, activities using in vitro models. Aqueous and ethanolic extracts were prepared. Afterwards, a liquid-liquid partition was developed using chloroform, ethyl acetate, and n-butanol. The extracts were characterized by LC-MS, and their biological activities were evaluated on epithelial cells (Vero), tumoral hepatic cells (Hep-G2), and THP-1 macrophages. LC-MS analyses identified several flavonoids in all fractions, such as quercetin, myricetin, and their glycosides. The crude extracts and n-butanol fractions did not present cytotoxicity to the cells. The non-toxic fractions presented significant antioxidant activity when evaluated in terms of DPPH scavenging activity, lipid peroxidation, and ROS inhibition. THP-1 macrophages treated with the n-butanol fraction (250 µg/mL) released fewer pro-inflammatory cytokines, even in the presence of LPS. In the future, it will be necessary to identify the phytochemicals that are responsible for anti-inflammatory effects for the discovery of new drugs. In vivo studies on M. albicans extracts are still required to confirm their possible mechanisms of action.


Asunto(s)
Melastomataceae , 1-Butanol , Antiinflamatorios/química , Antioxidantes/química , Cloroformo , Citocinas , Flavonoides/farmacología , Glicósidos , Humanos , Lipopolisacáridos , Fitoquímicos/farmacología , Extractos Vegetales/química , Quercetina/farmacología , Especies Reactivas de Oxígeno
19.
Ann Bot ; 127(5): 577-595, 2021 04 17.
Artículo en Inglés | MEDLINE | ID: mdl-33151331

RESUMEN

BACKGROUND AND AIMS: Much of our understanding of the ecology and evolution of seed dispersal in the Neotropics is founded on studies involving the animal-dispersed, hyperdiverse plant clade Miconia (Melastomataceae). Nonetheless, no formal attempt has been made to establish its relevance as a model system or indeed provide evidence of the role of frugivores as Miconia seed dispersers. METHODS: We built three Miconia databases (fruit phenology/diaspore traits, fruit-frugivore interactions and effects on seed germination after gut passage) to determine how Miconia fruiting phenology and fruit traits for >350 species interact with and shape patterns of frugivore selection. In addition, we conducted a meta-analysis evaluating the effects of animal gut passage/seed handling on Miconia germination. KEY RESULTS: Miconia produce numerous small berries that enclose numerous tiny seeds within water- and sugar-rich pulps. In addition, coexisting species provide sequential, year long availability of fruits within communities, with many species producing fruits in periods of resource scarcity. From 2396 pairwise interactions, we identified 646 animal frugivore species in five classes, 22 orders and 60 families, including birds, mammals, reptiles, fish and ants that consume Miconia fruits. Endozoochory is the main dispersal mechanism, but gut passage effects on germination were specific to animal clades; birds, monkeys and ants reduced seed germination percentages, while opossums increased it. CONCLUSIONS: The sequential fruiting phenologies and wide taxonomic and functional diversity of animal vectors associated with Miconia fruits underscore the likely keystone role that this plant clade plays in the Neotropics. By producing fruits morphologically and chemically accessible to a variety of animals, Miconia species ensure short- and long-distance seed dispersal and constitute reliable resources that sustain entire frugivore assemblages.


Asunto(s)
Melastomataceae , Dispersión de Semillas , Animales , Conducta Alimentaria , Frutas , Germinación , Semillas
20.
Am J Bot ; 108(4): 628-646, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33745129

RESUMEN

PREMISE: The woody plant group Memecylon (Melastomataceae) is a large clade occupying diverse forest habitats in the Old World tropics and exhibiting high regional endemism. Its phylogenetic relationships have been previously studied using ribosomal DNA with extensive sampling from Africa and Madagascar. However, divergence times, biogeography, and character evolution of Memecylon remain uninvestigated. We present a phylogenomic analysis of Memecylon to provide a broad evolutionary perspective of this clade. METHODS: One hundred supercontigs of 67 Memecylon taxa were harvested from target enrichment. The data were subjected to coalescent and concatenated phylogenetic analyses. A timeline was provided for Memecylon evolution using fossils and secondary calibration. The calibrated Memecylon phylogeny was used to elucidate its biogeography and ancestral character states. RESULTS: Relationships recovered by the phylogenomic analyses are strongly supported in both maximum likelihood and coalescent-based species trees. Memecylon is inferred to have originated in Africa in the Eocene and subsequently dispersed predominantly eastward via long-distance dispersal (LDD), although a reverse dispersal from South Asia westward to the Seychelles was postulated. Morphological data exhibited high levels of homoplasy, but also showed that several vegetative and reproductive characters were phylogenetically informative. CONCLUSIONS: The current distribution of Memecylon appears to be the result of multiple ancestral LDD events. Our results demonstrate the importance of the combined effect of geographic and paleoclimatic factors in shaping the distribution of this group in the Old World tropics. Memecylon includes a number of evolutionarily derived morphological features that contribute to diversity within the clade.


Asunto(s)
Melastomataceae , África , Asia , Teorema de Bayes , Evolución Molecular , Madagascar , Filogenia , Filogeografía
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA