Alkaloid Profiling and Cholinesterase Inhibitory Potential of Crinum × amabile Donn. (Amaryllidaceae) Collected in Ecuador

Natural products are one of the main sources for developing new drugs. The alkaloids obtained from the plant family Amaryllidaceae have interesting structures and biological activities, such as acetylcholinesterase inhibition potential, which is one of the mechanisms used for the palliative treatment of Alzheimer's disease symptoms. Herein we report the alkaloidal profile of bulbs and leaves extracts of Crinum × amabile collected in Ecuador and their in vitro inhibitory activity on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes. Using Gas Chromatography coupled to Mass Spectrometry (GC-MS), we identified 12 Amaryllidaceae alkaloids out of 19 compounds detected in this species. The extracts from bulbs and leaves showed great inhibitory activity against AChE and BuChE, highlighting the potential of Amaryllidaceae family in the search of bioactive molecules. Keywords: Amaryllidaceae alkaloids, Crinum × amabile, AChE, BuChE, GC-M

Chemical profiling and cholinesterase inhibitory activity of five Phaedranassa Herb. (Amaryllidaceae) species from Ecuador

It is estimated that 50 million people in the world live with dementia, 60-70% of whom suffer from Alzheimer's disease (AD). Different factors are involved in the development of AD, including a reduction in the cholinergic neurotransmission level. The Amaryllidaceae plant family contains an exclusive, large, and still understudied alkaloid group characterized by a singular skeleton arrangement and a broad spectrum of biological activities. The chemistry and biodiversity of Ecuadorian representatives of the Phaedranassa genus (Amaryllidaceae) have not been widely studied. In this work, five Ecuadorian Phaedranassa species were examined in vitro for their activity towards the enzymes acetyl- (AChE) and butyrylcholinesterase (BuChE), and the alkaloid profile of bulb extracts was analyzed by GC-MS. The species Phaedranassa cuencana and Phaedranassa dubia showed the most AChE and BuChE inhibitory activity, respectively. To obtain insight into the potential role of the identified alkaloids in these inhibitory effects, docking experiments were carried out, and cantabricine showed in silico inhibitory activity against both cholinesterase structures. Our results show that Amaryllidaceae species from Ecuador are a potential source of new drugs for the palliative treatment of AD

Genetic Diversity and Chemical Profile of Rhodophiala bifida Populations from Brazil

Rhodophiala bifida (Herb.) Traub, Amaryllidaceae, is a species native to South America known to produce alkaloids with potential pharmacological uses such as montanine, which has anti-inflammatory potential. R. bifida could be applied as a natural source of montanine. It is important to understand the genetic diversity of this species in order to assess the sustainable use of this plant. The aim of this study was to evaluate the genetic diversity and chemical profiles of the two known natural populations of R. bifida in Brazil. This report is the first population genetic study of R. bifida. We studied 93 individuals with six Inter-Simple Sequence Repeats (ISSR) primers. A total of 79 loci were amplified. Our results showed high-population structure (Fst = 0.16), with greatest genetic variation at the intrapopulation level. Genetic analyses separated the individuals of R. bifida into two clusters that corresponded to each of the natural populations. Chemical profile evaluation was carried out on dried bulbs, leaves, flowers, and flower scapes by liquid chromatography and mass spectrometry. Montanine and nangustine were the main metabolites identified in both populations. These alkaloids concentrations differed by population and by plant part

Phylogenetic Analysis of Seven WRKY Genes across the Palm Subtribe Attaleinae (Arecaceae) Identifies Syagrus as Sister Group of the Coconut

BACKGROUND:The Cocoseae is one of 13 tribes of Arecaceae subfam. Arecoideae, and contains a number of palms with significant economic importance, including the monotypic and pantropical Cocos nucifera L., the coconut, the origins of which have been one of the "abominable mysteries" of palm systematics for decades. Previous studies with predominantly plastid genes weakly supported American ancestry for the coconut but ambiguous sister relationships. In this paper, we use multiple single copy nuclear loci to address the phylogeny of the Cocoseae subtribe Attaleinae, and resolve the closest extant relative of the coconut. METHODOLOGY/PRINCIPAL FINDINGS:We present the results of combined analysis of DNA sequences of seven WRKY transcription factor loci across 72 samples of Arecaceae tribe Cocoseae subtribe Attaleinae, representing all genera classified within the subtribe, and three outgroup taxa with maximum parsimony, maximum likelihood, and Bayesian approaches, producing highly congruent and well-resolved trees that robustly identify the genus Syagrus as sister to Cocos and resolve novel and well-supported relationships among the other genera of the Attaleinae. We also address incongruence among the gene trees with gene tree reconciliation analysis, and assign estimated ages to the nodes of our tree. CONCLUSIONS/SIGNIFICANCE:This study represents the as yet most extensive phylogenetic analyses of Cocoseae subtribe Attaleinae. We present a well-resolved and supported phylogeny of the subtribe that robustly indicates a sister relationship between Cocos and Syagrus. This is not only of biogeographic interest, but will also open fruitful avenues of inquiry regarding evolution of functional genes useful for crop improvement. Establishment of two major clades of American Attaleinae occurred in the Oligocene (ca. 37 MYBP) in Eastern Brazil. The divergence of Cocos from Syagrus is estimated at 35 MYBP. The biogeographic and morphological congruence that we see for clades resolved in the Attaleinae suggests that WRKY loci are informative markers for investigating the phylogenetic relationships of the palm family

Taxonomy based on science is necessary for global conservation

Peer reviewe

Actualización del Estado de Conservación de la Ashpa cebolla (Phaedranassa schizantha), una Especie Endémica de la Sierra Central del Ecuador

Phaedranassa schizantha(Amaryllidaceae), known as “ashpa cebolla” or “fake onion”, is a bulbous plantspecies endemic to the central Andes of Ecuador. With a restricted geographic distribution and few po-pulations,P. schizanthais classified as Endangered under the International Union for the Conservation ofNature red list of threatened species criteria. The variety ignea, limited to the area close to A mbato city, iscategorized as Critically Endangered following the same standards. The objective of this research is toupdate the conservation status of P. schizantha. After analyzing the population genetic structure of twelvelocalities using microsatellite loci, I did not find genetic evidence to separate genetically the species intotwo varieties. Therefore, I suggest that the varieties schizantha a nd ignea are synonyms and their degreeof threatened need to be assessed as one taxon. Based on the extension of presence of the species, Irecommend maintaining the category “Endangered” for P. schizantha, under the International Union forthe Conservation of Nature red list criteriaPhaedranassa schizantha (Amaryllidaceae), conocida como “ashpa cebolla” o “falsa cebolla”, es una especie de planta bulbosa endémica de la sierra central del Ecuador. Debido a su distribución geográfica restringida y al reducido número de poblaciones, P. schizantha se encuentra categorizada como En Peligro de Extinción según los criterios de la lista roja para especies en peligro de la Unión Internacional para la Conservación de la Naturaleza.La variedad ignea, localizada alrededor de Ambato, está clasificada como En Peligro Crítico, según los mismos estándares. El objetivo de esta investigación es actualizar el estado de conservación de P. schizantha. Tras analizar la estructura genética en doce localidades, utilizando microsatelites, no se encontraron diferencias genéticas que justifiquen la separación de la especie en dos variedades. Se sugiere que las variedades schizantha e ignea sean consideras sinónimos y se clasifique el grado de amenaza de la especie como un solo taxón. Basada en la extensión de presencia de la especie, recomiendo mantener la categoría de “En Peligro” para P. schizantha, según los criterios de la lista roja de la Unión Internacional para la Conservación de la Naturaleza

Evolutionary history of CAM photosynthesis in Neotropical Clusia : insights from genomics, anatomy, physiology and climate.

Clusia is a remarkable genus of Neotropical woody plants as its members engage in either C3 photosynthesis or employ, to varying degrees, crassulacean acid metabolism (CAM) photosynthesis. Information about the evolutionary history of CAM in Clusia is scarce. Restriction site-associated sequencing of 64 species (20% of the genus) provided strong support for most of the previously recognized nine lineages. Ancestral reconstruction using maximum parsimony or maximum likelihood under a one-rate model suggested that CAM evolved at least four times independently from a most recent common ancestor (MRCA) with C3, whereas a maximum likelihood two-rate model suggested that CAM was already present in the MRCA followed by reversions to C3 in several lineages. Phylogenetic generalized least square analysis assessed variation in seven leaf anatomical traits and CAM activity measured as δ 13C. Results indicate that CAM is highly correlated with palisade mesophyll layer thickness and cell size. In addition, correlation between 19 bioclimatic variables and δ 13C was evaluated. It was found that CAM is positively correlated with habitats with a more severe dry season and greater precipitation seasonality. Since CAM is weakly and/or only periodically expressed in many Clusia spp., and thus not readily reflected in δ 13C, future analysis of phylogenetically-informed CAM expression in Clusia must include physiological measurements such as CO2 exchange and/or diel changes in leaf acidity for each species under investigation

Correction: Oleas, N.H., et al. Muddy Boots Beget Wisdom: Implications for Rare or Endangered Plant Species Distribution Models. Diversity, 2019, 11, 10

An error on our paper [...

Muddy Boots Beget Wisdom: Implications for Rare or Endangered Plant Species Distribution Models

Species distribution models (SDMs) are popular tools for predicting the geographic ranges of species. It is common practice to use georeferenced records obtained from online databases to generate these models. Using three species of Phaedranassa (Amaryllidaceae) from the Northern Andes, we compare the geographic ranges as predicted by SDMs based on online records (after standard data cleaning) with SDMs of these records confirmed through extensive field searches. We also review the identification of herbarium collections. The species’ ranges generated with corroborated field records did not agree with the species’ ranges based on the online data. Specifically, geographic ranges based on online data were significantly inflated and had significantly different and wider elevational extents compared to the ranges based on verified field records. Our results suggest that to generate accurate predictions of species’ ranges, occurrence records need to be carefully evaluated with (1) appropriate filters (e.g., altitude range, ecosystem); (2) taxonomic monographs and/or specialist corroboration; and (3) validation through field searches. This study points out the implications of generating SDMs produced with unverified online records to guide species-specific conservation strategies since inaccurate range predictions can have important consequences when estimating species’ extinction risks