Biologically-active compounds from Brazilian lichens and their affinity with ether

It can be obtained from lichens biologically-active extracts and pure substances, many of them of phenolic nature. They are usually obtained by using organic solvents, such as diethyl ether. In this paper the usefulness of ether for the obtainment of crude extracts and the subsequent purification of pure substances from Brazilian lichen is reviewed, as well as alternatives to their production through cells or thallus immobilization in bioreactors and their entrapment in inert matrix

Ultrastructural Analysis of Leishmania infantum chagasi

Leishmaniasis is considered by the World Health Organization as one of the infectious parasitic diseases endemic of great relevance and a global public health problem. Pentavalent antimonials used for treatment of this disease are limited and new phytochemicals emerge as an alternative to existing treatments, due to the low toxicity and cost reduction. Usnic acid is uniquely found in lichens and is especially abundant in genera such as Alectoria, Cladonia, Evernia, Lecanora, Ramalina, and Usnea. Usnic acid has been shown to exhibit antiviral, antiprotozoal, antiproliferative, anti-inflammatory, and analgesic activity. The aim of this study was to evaluate the antileishmanial activity of usnic acid on Leishmania infantum chagasi promastigotes and the occurrence of drug-induced ultrastructural damage in the parasite. Usnic acid was effective against the promastigote forms (IC50 = 18.30 ± 2.00 µg/mL). Structural and ultrastructural aspects of parasite were analyzed. Morphological alterations were observed as blebs in cell membrane and shapes given off, increasing the number of cytoplasmic vacuoles, and cellular and mitochondrial swelling, with loss of cell polarity. We concluded that the usnic acid presented antileishmanial activity against promastigote forms of Leishmania infantum chagasi and structural and ultrastructural analysis reinforces its cytotoxicity. Further, in vitro studies are warranted to further evaluate this potential

Soil biochemistry and microbial activity in vineyards under conventional and organic management at Northeast Brazil.

The São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that orgThe São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that organic fertilization can improve soil quality, we compared the effects of conventional and organic soil management on microbial activity and mycorrhization of seedless grape crops. We measured glomerospores number, most probable number (MPN) of propagules, richness of arbuscular mycorrhizal fungi (AMF) species, AMF root colonization, EE-BRSP production, carbon microbial biomass (C-MB), microbial respiration, fluorescein diacetate hydrolytic activity (FDA) and metabolic coefficient (qCO2). The organic management led to an increase in all variables with the exception of EE-BRSP and qCO2. Mycorrhizal colonization increased from 4.7% in conventional crops to 15.9% in organic crops. Spore number ranged from 4.1 to 12.4 per 50 g-1 soil in both management systems. The most probable number of AMF propagules increased from 79 cm-3 soil in the conventional system to 110 cm-3 soil in the organic system. Microbial carbon, CO2 emission, and FDA activity were increased by 100 to 200% in the organic crop. Thirteen species of AMF were identified, the majority in the organic cultivation system. Acaulospora excavata, Entrophospora infrequens, Glomus sp.3 and Scutellospora sp. were found only in the organically managed crop. S. gregaria was found only in the conventional crop. Organically managed vineyards increased mycorrhization and general soil microbial activity

Potential phenolic bioherbicides from Cladonia verticillaris produce ultrastructural changes in Lactuca sativa seedlings

The possibilities for using phenolics, extracted from the lichen Cladonia verticillaris with different organic solvents, as bioherbicides have herein been studied through observation of the ultrastructural changes produced in Lactuca sativa seedlings. The different extracts mainly contain protocetraric and fumarprotocetraric acids and very small amounts of atranorin. It has been observed that the roots of lettuce seedlings grow more rapidly in the presence of the phenols than in their absence. This fact is supported by a minor number of lobes and less indentation of the parenchymatous cells as well as a major appearance of active dictyosomes in their cytoplasm. Nevertheless, seedling leaves developed in the presence of these extracts show drastic degenerative changes. Intergranal lamellae of chloroplasts disappear whereas thylakoids are melted in amorphous masses. In some cases, the number of dictyosomes increases in parenchymatous cells and mitochondria disorganize their internal membranes, though in a minor degree of that observed for chloroplasts

Effects of both urea and light on the ability of Accumulation and se- cretion of proteins and phenolics by Cladonia verticillaris

Pernambuco (Brazil) in which sugar cane cultures are often established and fertilized by urea. The thalli of the above mentioned lichen are ex- perimentally maintained on different concentrations of urea in light or in darkness, conditions that simulate agricultural uses. The capture of the external urea by the thalli was higher in light than in the dark depending on the urea concentration. Urea inside the thallus is hydrolyzed by in- duced urease to produce both carbon dioxide and ammonia. This implies an increase of the protein production, a part of which is secreted to the media whereas another part is retained by the thallus. Both secretion and retention of proteins are increased by light. Production of lichen phenolics, protocetraric and fumarprotocetraric acids, increases in light and fumarprotocetraric acid mainly migrates to the cortex. Both production and migration are slightly effected by urea