Low-cost alternative for the bioproduction of bioactive phenolic compounds of callus cultures from Cereus hildmannianus (K.) Schum.

The aim of this study was to establish a sustainable alternative callus culture of Cereus hildmannianus for the production and bioactive determination of phenolic compounds from this species. The conventional callus was cultivated using agar and Murashige and Skoog (MS) medium, while for the alternative culture the agar was replaced with a cotton support covered with filter paper and MS medium (incubated at 32 °C with photoperiod of 16 h), and the morphological characteristics and growth index were assessed (8 weeks). Extracts were obtained by maceration followed by partition, characterized by nuclear magnetic resonance - NMR and ultra-high performance liquid chromatography - UHPLC, quantified (phenolic compounds) by UV-Vis methods, and their antioxidant, antitumor activities, as well as cytotoxicity, were evaluated. The establishment of an alternative callus culture was carried out successfully. Characteristic signals of phenolic compounds were determined by NMR, and 46 compounds with fragment ions were identified using UHPLC analysis. The highest concentrations of phenolic compounds, and greatest antioxidant and antitumor activities, were obtained with the dichloromethane fractions of both callus tissue cultures, which were not cytotoxic. The callus culture from C. hildmannianus has shown promise as a source for the sustainable production of phenolic compounds with antioxidant and antiproliferative activities and thus, has potential use as a natural antitumor product.

Cereus peruvianus Mill. (Cactaceae) as a source of natural antioxidants: Phenolic compounds and antioxidant activity of cladode extracts in two collection periods.

The economic potential of the cactus species Cereus peruvianus Mill. (syn. C. hildmannianus K. Schum.) has already been demonstrated through the generation of products and patents. However, the phenolic compounds and antioxidant activity have not yet been evaluated. The aim of our study was to determine the total phenolic compounds, evaluate the antioxidant activity and characterize the phenolic compounds of cladode extracts from C. peruvianus grown in the southern region of Brazil, in two collection periods. Higher total content of phenolic compounds and antioxidant activity were detected in the cladode extract collected in 2016 than in the cladode extract collected in 2015. The profile of phenolic compounds identified five flavonoids that had not previously been reported in species of the genus Cereus. The phenolic compounds linked to antioxidant activities identified in the cladode extract from C. peruvianus support the use of this species in human food as a source of natural antioxidants.

Genetic diversity of maize germplasm assessed by retrotransposon-based markers.

Maize is one of the most important crops and also a model for grass genome research. Transposable elements comprise over 78% of the maize genome and their ability to generate new copies makes them good potential markers. Interretrotransposon-amplified polymorphism (IRAP) and retrotransposon microsatellite amplified polymorphism (REMAP) protocols were used for the first time in maize to study the genetic variability between maize cultivars. Ten PCR primers were selected based on a systematic analysis of the sequence conservation in the extremities of different high copy number transposable elements, whereas one primer was chosen based on a microsatellite sequence. Of the 16 primer combinations tested, 14 produced polymorphic bands. These markers were used to identify genetic similarity among 20 maize cultivars selected by their different kernel oil content. Genetic similarity analysis was performed based on the polymorphic band profiles and dendrograms were developed by the unweighted pair-group method with arithmetic averages. Clustering technique revealed that samples were grouped into three clusters that differed in their kernel oil content and size, and in their relative embryo size. In the current investigation, there is evidence that IRAP/REMAP may be useful as markers in maize.