Antioxidant Activity and Phytopathogenic Control of Extracts and Fraction from Struthanthus calophyllus A.C.Sm. (Loranthaceae).

Phytopathogenic microorganisms cause oxidative stress in host plants, thus affecting agricultural crops. Such stress could be controlled by antioxidant compounds from parasitic plants, given their antioxidant power. This article reports an evaluation of Struthanthus calophyllus antimicrobial activity and antioxidant mechanism by testing different polarity extracts. Antimicrobial activity was evaluated against phytopathogens bacteria (e. g., Erwinia, Pectobacterium, Xanthomonas) using the agar diffusion method. Pectobacterium and Xanthomonas presented growth inhibition zones similar to streptomycin control. Antioxidant activity was determined by measuring total phenol content, DPPH⋅, and ABTS⋅+ radicals-scavenging inhibition percentage (IP). Most polar extracts presented 76,9-95,9 % IP, which correlates with its phenolic content. Besides, Nuclear Magnetic Resonance in a V14-1 sub-fraction from stem ethanolic extract, chose one for highest yield percentage, highest metabolites presence, and antimicrobial activity, showed triterpenic compounds mixture (α-amyrin, ß-amyrin and 24-methylenecycloartanol). Findings in this study are among the first reports for S. calophyllus, even the chemical characterization, that confirm its strong antioxidant and antibacterial activities. Further molecular composition research about parasitic plants could show how unknown compounds may combat pathogenic microorganisms.

Evolutionary Developmental Biology (Evo-Devo) Research in Latin America.

Famous for its blind cavefish and Darwin's finches, Latin America is home to some of the richest biodiversity hotspots of our planet. The Latin American fauna and flora inspired and captivated naturalists from the nineteenth and twentieth centuries, including such notable pioneers such as Fritz Müller, Florentino Ameghino, and Léon Croizat who made a significant contribution to the study of embryology and evolutionary thinking. But, what are the historical and present contributions of the Latin American scientific community to Evo-Devo? Here, we provide the first comprehensive overview of the Evo-Devo laboratories based in Latin America and describe current lines of research based on endemic species, focusing on body plans and patterning, systematics, physiology, computational modeling approaches, ecology, and domestication. Literature searches reveal that Evo-Devo in Latin America is still in its early days; while showing encouraging indicators of productivity, it has not stabilized yet, because it relies on few and sparsely distributed laboratories. Coping with the rapid changes in national scientific policies and contributing to solve social and health issues specific to each region are among the main challenges faced by Latin American researchers. The 2015 inaugural meeting of the Pan-American Society for Evolutionary Developmental Biology played a pivotal role in bringing together Latin American researchers eager to initiate and consolidate regional and worldwide collaborative networks. Such networks will undoubtedly advance research on the extremely high genetic and phenotypic biodiversity of Latin America, bound to be an almost infinite source of amazement and fascinating findings for the Evo-Devo community.

Comparative inflorescence development in selected Andean Santalales.

PREMISE OF THE STUDY: Loranthaceae, Santalaceae, and Viscaceae are the most diversified hemiparasitic families of Santalales in the Andes. Their partial inflorescences (PIs) vary from solitary flowers, or dichasia in most Santalales, to congested floral groups along articles in most Viscaceae. The atypical articled inflorescences in Phoradendreae (Viscaceae), a phylogenetic novelty restricted to this tribe, have been variously described as racemes, spikes, fascicles, or as intercalary inflorescences, but no developmental studies have been performed to compare them with the construction of PIs across Santalales. METHODS: We used standard light microscopy and scanning electron microscopy to record the inflorescence development in members of Phoradendreae (Viscaceae) in comparison to those in species of Aetanthus, Gaiadendron, Oryctanthus, Passovia, and Peristethium (Loranthaceae) and Antidaphne (Santalaceae). KEY RESULTS: Morphological and developmental comparisons as well as optimization onto a phylogenetic framework indicate that individual inflorescences in Santalales are indeterminate and are formed by axillary cymose PIs. The latter correspond to dichasia, either simple, compound, or variously reduced by abortion of lateral flowers, abortion of the terminal flower, or loss of bracteoles. CONCLUSIONS: Dichasia are plesiomorphic in Santalales. These results favor the interpretation that inflorescences in Phoradendreae are formed by the fusion of serial dichasia (=floral rows) with the main inflorescence axis via syndesmy. We compared this interpretation with the competing one based on the co-occurrence of collateral and serial floral buds.

Pharmacological potential of parasitic Angiosperms against microorganisms / Potencial farmacológico de Angiospermas parásitas contra microorganismos

Parasitic habit plants arouse great interest for their extraordinary growth adaptations and produce different secondary metabolites that allow them to survive the extreme conditions in which they develop. This can provide a range of compounds with multiple uses. However, those plants have been poorly explored and there is very little information about their natural compounds, some healing properties attributed to several communities have been scientifically supported. Articles were consulted in databases (Google Scholar, PubMed, Scielo, Science Direct, Scopus) considering the biological activity reported until June 2021. Parasitic plants present mainly antibacterial activity, some species antifungal moderate activity, and to a lesser extent were found reports of antiprotozoal activity. The composition of parasitic plants should continue to be investigated, which could be an alternative to combat various microorganisms that cause diseases, even resistant to traditional medicines.

Las plantas parásitas despiertan gran interés por sus adaptaciones extraordinarias de crecimiento, y producir diversos metabolitos secundarios que les permiten desarrollarse en condiciones extremas, lo que puede brindar un abanico de compuestos con múltiples usos. Sin embargo, estas plantas han sido pobremente exploradas y es muy poca la información que se tiene de sus compuestos naturales, se han soportado científicamente algunas propiedades curativas, atribuidas por diferentes comunidades. Se consultaron artículos en bases de datos (Google Scholar, PubMed, Scielo, Science Direct, Scopus), teniendo en cuenta la actividad biológica reportada hasta agosto de 2019. Las plantas parásitas presentan principalmente actividad antibacteriana, algunas especies con actividad antifúngica moderada, y en menor proporción reportes de actividad antiprotozoaria. Debe continuarse indagando la composición molecular de estas plantas, lo que podría ser una alternativa para combatir diversos microorganismos causantes de enfermedades, incluso aquellos resistentes a los medicamentos tradicionales.