Antecedentes y Objetivos: Uno de los enfoques más recientes para delimitar especies vegetales es el uso de caracteres anatómicos de la madera en representantes leñosos que ha sido poco explorado en taxones mexicanos. El género Forestiera (Oleaceae) es un ejemplo de esto, pues solo se ha descrito la madera de dos de las 12 especies distribuidas en México. Con el objetivo de contribuir al conocimiento de la anatomía de la madera del género, así como a la búsqueda de caracteres anatómicos que discriminen entre sus especies, en el presente estudio se describe la anatomía de la madera de ocho especies de Forestiera distribuidas en México con un enfoque sistemático. Métodos: Se analizaron 42 muestras de madera de ocho especies, provenientes de tres individuos por especie en 14 sitios de colecta. El material se procesó con microtecnia convencional para obtener variables anatómicas cualitativas y cuantitativas. Estas fueron evaluadas con estadística multivariada para determinar cuáles son importantes para formar grupos de especies en Forestiera. Resultados clave: Algunos atributos anatómicos reportados anteriormente coinciden con los observados en este trabajo. Sin embargo, hay diferencias como la porosidad semianular y la delimitación de marcas de crecimiento sin presencia de parénquima marginal. Los análisis formaron grupos de especies dados por el diámetro de vasos de la madera temprana, longitud de elementos de vaso y fibras, diámetro de las fibras, tipo de radios, abundancia del parénquima marginal y tipo de cristales en los radios. Con base en la anatomía de la madera, se propone una clave taxonómica para identificar las especies estudiadas. Conclusiones: Mediante los análisis empleados se contribuye al conocimiento de la anatomía de la madera de Forestiera; además, se reconocen caracteres que permiten distinguir grupos de especies. Futuros estudios confirmarán su valor taxonómico.

Verbesina sphaerocephala A. Gray, like other wild plants of the genus Verbesina, has been used in herbal medicine. There is information for other species of the genus related to their phenolic content, antioxidant capacity, and isolation of bioactive compounds with antimicrobial activity. However, there are no reports for V. sphaerocephala, although it has an important presence in the state of Michoacán, México. In this study, the phenolic composition, quantification of rutin, and in vitro antioxidant and antibacterial activities of methanolic extracts from V. sphaerocephala leaves and flowers were determined. The results showed that all the investigated extracts have high phenolic and flavonoid contents. The flavonoid rutin was identified in all the extracts from V. sphaerocephala by high-performance thin-layer chromatography (HPTLC). The V. sphaerocephala extracts showed scavenging activity against DPPH^• and ABTS^•+ radicals (IC₅₀ and 5.83 ± 0.50 and 0.93 ± 0.01 mg/mL, respectively) as well as relevant antioxidant capacity (51.05 ± 0.36 mg of ascorbic acid/g of dry tissue). The experimental results show that V. sphaerocephala extracts possessed a strong antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria. This research indicates that V. sphaerocephala could be considered as a potential source of natural compounds from the point of ethnopharmacological usage.

Cosmos sulphureus Cav. (Asteraceae), and endemic plant of Mexico is used in herbal medicine. In this study, the phytochemical composition, phenolic content, and antioxidant activity of ethanolic and methanolic extracts from C. sulphureus leaves and flowers were determined. The phytochemical analysis showed the presence of compounds such as terpenoids, phenolic compounds, tannins, and flavonoids and the absence of alkaloids, saponins, glycosides, and anthraquinones. The experimental results showed that the extracts have high contents of phenolic, flavonoid, and condensed tannins contents. The phenolic compounds identified in the C. sulphureus extracts by high-performance thin-layer chromatography (HPTLC) include phenolic acids such as chlorogenic acid and caffeic acid as well flavonoids such as rutin and quercetin. The C. sulphureus extracts showed a relevant free radical scavenging activity, ferric-reducing antioxidant power, lipid peroxidation inhibition ability, and oxygen radical antioxidant capacity. This research highlights the phytochemical profile and antioxidant activity of phenolic compounds-rich extracts from C. sulphureus leaves and flowers.

The genus Coryphantha includes plants with globose to cylindrical stems bearing furrowed tubercles, flowers arising at the apex, and seeds with flattened testa cells. Coryphantha is the second richest genus in the tribe Cacteae. Nevertheless, the genus lacks a phylogenetic framework. The limits of Coryphantha with its sister genus Escobaria and the infrageneric classification of Coryphantha have not been evaluated in a phylogenetic study. In this study we analyzed five chloroplast regions (matK, rbcL, psbA-trnH, rpl16, and trnL-F) using Bayesian phylogenetic analysis. We included 44 species of Coryphantha and 43 additional species of the tribe Cacteae. Our results support the monophyly of Coryphantha by excluding C. macromeris. Escobaria + Pelecyphora + C. macromeris are corroborated as the sister group of Coryphantha. Within Coryphantha our phylogenetic analyses recovered two main clades containing seven subclades, and we propose to recognize those as two subgenera and seven sections, respectively. Also, a new delimitation of Pelecyphora including C. macromeris and all species previously included in Escobaria is proposed. To accommodate this new delimitation 25 new combinations are proposed. The seven subclades recovered within Coryphantha are morphologically and geographically congruent, and partially agree with the traditional classification of this genus.

Several plant extracts exhibit anti-virulence properties due to the interruption of bacterial quorum sensing (QS). However, studies on their effects at the preclinical level are scarce. Here, we used a murine model of abscess/necrosis induced by Pseudomonas aeruginosa to evaluate the anti-pathogenic efficacy of 24 plant extracts at a sub-inhibitory concentration. We analyzed their ability to inhibit QS-regulated virulence factors such as swarming, pyocyanin production, and secretion of the ExoU toxin via the type III secretion system (T3SS). Five of the seven extracts with the best anti-pathogenic activity reduced ExoU secretion, and the extracts of Diphysa americana and Hibiscus sabdariffa were identified as the most active. Therefore, the abscess/necrosis model allows identification of plant extracts that have the capacity to reduce pathogenicity of P. aeruginosa. Furthermore, we evaluated the activity of the plant extracts on Chromobacterium violaceum. T3SS (ΔescU) and QS (ΔcviI) mutant strains were assessed in both the abscess/necrosis and sepsis models. Only the ΔescU strain had lower pathogenicity in the animal models, although no activity of plant extracts was observed. These results demonstrate differences between the anti-virulence activity recorded in vitro and pathogenicity in vivo and between the roles of QS and T3S systems as virulence determinants.

Antecedentes: Tagetes contiene cerca de 55 especies, su mayor centro de diversificación se encuentra en México con 35. Cerca del 10 % de las especies tienen importancia en el ámbito cultural y económico. A la fecha, se carece de estudios anatómicos en la mayoría de ellas. Pregunta: ¿Existen caracteres anatómicos foliares de valor diagnóstico que permitan discriminar entre las nueve especies de Tagetes estudiadas? Especies de estudio: Tagetes lacera , T. lemmonii , T. linifolia , T. lucida , T. lunulata , T. micrantha , T. parryi , T. stenophylla , T. zypaquirensis . Sitio de estudio y fecha: Áreas de distribución natural en el Altiplano Mexicano, Faja Volcánica Transmexicana y CampoExperimental de Fitotecnia, Universidad Autónoma Chapingo, Texcoco, Estado de México, durante el 2017. Métodos: Se recolectaron ejemplares botánicos. Sus hojas fueron fijadas y sometidas a técnicas convencionales de anatomía vegetal, se diafanizaron e incluyeron en parafina para su observación y análisis. Resultados: Las especies de Tagetes desarrollan hojas enteras y pinnatisectas, el patrón de venación secundaria fue eucamptódromo tornándose reticulódromo distalmente y broquidódromo simple y festoneado. La venación última marginal fue incompleta excepto de T. lunulata . Se observaron abundantes y diversos tricomas, mesofilo dorsiventral e isolateral, haces colaterales con vaina y canales en el mesofilo y en la vena media . Conclusiones: La arquitectura y la anatomía foliar de las especies estudiadas revela caracteres comunes en Asteraceae. Sin embargo, en Tagetes el tipo de tricomas, de mesofilo, tamaño de los canales y esclerénquima asociada a los haces vasculares son importantes. Translate stop