The Melastomataceae family, the seventh largest flowering plants, has been studied in several fronts of natural product chemistry, including terpenoids, simple phenolics, flavonoids, quinones, lignans and their glycosides, as well as a vast range of tannins or polyphenols. This review concerns the phenolic and polyphenolic metabolites described in the literature for several genera of this family, the mode of isolation and purification, and the structure elucidation of these new natural products that has been achieved by extensive spectral analyses, including ESI-MS, ¹H-, ¹³C-NMR spectra and two-dimensional experiments, COSY, TOCSY, J-resolved, NOESY, HMQC, DEPT, and HMBC, as well as chemical and enzymatic degradations and the chemotaxonomic meaning. Finally, a general biogenetic pathway map for ellagitannins is proposed on the bases of the most plausible free radical C-O oxidative coupling.

Textile wastewater (TWW) is one of the most hazardous wastewaters for ecosystems when it is discharged directly into water streams without adequate treatment. Some organic pollutants, such as dyes in TWW, are considered refractory compounds that are difficult to degrade using conventional chemical and biological methods. The bicarbonate-activated peroxide (BAP) system is an advanced oxidation process (AOP) based on applying H₂O₂, which has been demonstrated to be a clean and efficient technology for dye degradation, with the advantage of operating under slightly alkaline pH conditions. In this study, response surface methodology (RSM) based on a central composite design (CCD) was used to optimize the degradation of TWW contaminated with the azo dye Acid Black 194 using the BAP system catalyzed with cobalt ions in solution (Co²⁺). The analysis of variance (ANOVA) technique was applied to identify significant variables and their individual and interactive effects on the degradation of TWW. The optimum reagent concentrations for degrading TWW at 25 °C and with 45 μM Co²⁺ were 787.61 and 183.34 mM for H₂O₂ and NaHCO₃, respectively. Under these conditions, complete decolorization (≥99.40), 32.20 % mineralization, and 52.02 % chemical oxygen demand removal were achieved. Additionally, the acute toxicity of textile wastewater before and after oxidation was evaluated with guppy fish (Poecilia reticulata), showing a total reduction in mortality after treatment with the Co²⁺–BAP system. The Co²⁺–BAP oxidation system is a potential method for textile wastewater treatment, which, in addition to achieving complete decolorization and partial mineralization, improves biodegradability and reduces the toxicity of the treated water.

Real textile wastewater (RTWW) poses significant environmental challenges. RTWW typically contains high levels of organic compounds, such as dyes, as well as inorganic substances like salts. These contaminants can harm aquatic life when released into water bodies without appropriate treatment. RTWW was subjected to a series of sequential treatments: exchange resins for removing ions, advanced oxidation with bicarbonate-activated peroxide to degrade organic matter, and a biological treatment based on the Zahn–Wellens test to remove remaining chemical oxygen demand (COD) The advanced oxidation process based on the activation of H₂O₂ with NaHCO₃ (catalyzed with cobalt impregnated on a pillared clay, Co/Al–PILC)) was optimized using central composite design (CCD) and response surface methodology (RSM). After the process integration, reductions in ion concentrations, chemical oxygen demand (COD), and total organic carbon content (TOC) were achieved. Reduced hardness (99.94%) and ions (SO₄²⁻ and acid black 194 dye of 99.88 and 99.46%, respectively), COD (96.64%), and TOC (96.89%), guaranteeing complete treatment of RTWW, were achieved. Additionally, the biodegradability index of RTWW increased from 0.28 ± 0.01 to 0.90 ± 0.01, and phytotoxicity was reduced, going from a phytotoxic that inhibited the germination of lettuce seeds to a phytostimulant after biological treatment with activated sludge.

Objetivo: Analizar los cambios fotosintéticos de las especies Eichhornia crassipes (Mart.) Solms, Pistia stratiotes L. y Salvinia auriculata Aubl. sometidas a un tratamiento con agua residual de mina. Metodología: Se expuso a las plantas a un tratamiento a escala de laboratorio con agua residual proveniente de una región minera de Caldas (Colombia) durante seis días (144 horas). Los componentes principales del agua se determinaron con test Nanocolor y los cambios fotosintéticos en las plantas durante la exposición al agua residual se determinaron por métodos espectrofotométricos. Resultados: El agua residual de mina es una matriz compleja cuyo componente mayoritario es el cianuro (CN-) con un valor de 175,00 mg/L superando las disposiciones del Ministerio de Ambiente y Desarrollo Sostenible de Colombia; las relaciones de clorofi la a/b y carotenos/clorofila total indicaron que las plantas E. crassipes y P. stratiotes respondieron al tratamiento modifi cando las concentraciones de los pigmentos analizados. Conclusiones: La planta E. crassipes disminuyó la relación clorofi la a/b como indicador de estrés, la planta P. stratiotes aumentó la relación carotenos/clorofi la total aumentando la síntesis de carotenos para proteger los tejidos contra el estrés y la planta S. auriculata fue la menos afectada, lo que se traduce en una alta tolerancia o adaptación de esta última especie a los cambios ambientales.

En la actualidad, la industria textil destaca por su contribución económica a nivel mundial. No obstante, su expansión conlleva una creciente inquietud debido al impacto ambiental y la generación masiva de aguas residuales altamente contaminadas. Estas aguas, provenientes de la industria textil, albergan una amplia gama de compuestos orgánicos nocivos, incluyendo colorantes, sustancias químicas persistentes, metales pesados y otros elementos, representando un desafío ambiental considerable y un riesgo significativo para los ecosistemas acuáticos y la salud humana. Este artículo se enfoca en la aplicación de la biorremediación y la biosorción, como métodos esenciales para abordar la problemática de la contaminación del agua derivada de la industria textil. Estos métodos han surgido como soluciones prometedoras y sostenibles frente a esta preocupación creciente, ofreciendo avances significativos en la mitigación de la contaminación del agua y un panorama esperanzador para el desarrollo sostenible de la industria textil. Su implementación adecuada y continuada puede conducir a prácticas más responsables y respetuosas con el medio ambiente para degradar y eliminar contaminantes utilizando microrganismos de manera efectiva.