Antioxidative, Antiproliferative and Antimicrobial Activities of Phenolic Compounds from Three Myrcia Species

Myrcia bella Cambess., Myrcia fallax (Rich.) DC. and Myrcia guianensis (Aubl.) DC. (Myrtaceae) are trees found in Brazilian Cerrado. They have been widely used in folk medicine for the treatment of gastrointestinal disorders, hemorrhagic and infectious diseases. Few reports have been found in the literature connecting their phenolic composition and biological activities. In this regard, we have profiled the main phenolic constituents of Myrcia spp. leaves extracts by ESI(−)Q-TOF-MS. The main constituents found were ellagic acid (M. bella), galloyl glucose isomers (M. guianensis) and hexahydroxydiphenic (HHDP) acid derivatives (M. fallax). In addition, quercetin and myricetin derivatives were also found in all Myrcia spp. extracts. The most promising antioxidant activity, measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, was found for M. fallax extracts (EC50 8.61 ± 0.22 µg·mL−1), being slightly less active than quercetin and gallic acid (EC50 2.96 ± 0.17 and 2.03 ± 0.02 µg·mL−1, respectively). For in vitro antiproliferative activity, M. guianensis showed good activity against leukemia (K562 TGI = 7.45 µg·mL−1). The best antimicrobial activity was observed for M. bella and M. fallax to Escherichia coli (300 and 250 µg·mL−1, respectively). In conclusion, the activities found are closely related to the phenolic composition of these plants

Produção de pigmentos do tipo azafilonas por Penicillium sclerotiorum.

Fungos são seres vivos que apresentam grande importância ecológica, econômica e industrial. Estes são conhecidos por serem capazes de biossintetizar metabólitos secundários úteis, especialmente para as indústrias farmacêutica e alimentícia. Dentre os biocompostos produzidos por esses organismos estão as azafilonas, pigmentos naturais com atividade antimicrobiana extraídos de fungos de diversos gêneros, entre eles o Penicillium. Considerando o potencial biotecnológico das espécies deste gênero e dos metabólitos produzidas por elas, este trabalho apresenta técnicas indutoras de desvios metabólicos (OSMAC) utilizadas no cultivo do fungo Penicillium sclerotiorum, endofítico isolado da planta Duguetia stelechantha (Annonaceae).bitstream/item/220307/1/diversidade-microbiana-da-amazonia-vol-3-p30a35.pd

On estimation and local influence analysis for measurement errors models under heavy-tailed distributions

EM algorithm, Mahalanobis distance, Measurement error models, Scale mixtures of normal distributions,