Publications by authors named "Katia Aparecida de Siqueira"

Unlabelled: Actinobacteria is a phylum composed of aerobic, Gram-positive, and filamentous bacteria with a broad spectrum of biological activity, including antioxidant, antitumor, and antibiotic. The crude extract of R132 was fractionated on a C18 silica column and the isolated compound was identified by H and C nuclear magnetic resonance as 3-(phenylprop-2-enoic acid), also known as -cinnamic acid. Antimicrobial activity against human pathogens was assayed in vitro (disk-diffusion qualitative test) and in vivo using larvae (RT-qPCR).

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Aspergillus sp. A31 and Curvularia geniculata P1 are endophytes that colonize the roots of Aeschynomene fluminensis Vell. and Polygonum acuminatum Kunth.

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Article Synopsis
  • The study focused on how dark septate endophytic fungi interact with cowpea plants under salt stress, specifically isolating two types of fungi from Vochysia divergens roots.
  • The research found that while salinity negatively affected nutrient levels in cowpea plants, root colonization by the selected fungi improved nitrogen and phosphorus nutrition, promoting growth and photosynthesis.
  • Notably, these beneficial effects were only significant at moderate salinity levels, indicating a limit to the fungi's positive impact in highly saline conditions.
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Here, we report the draft genome sequence of the strain I43, which is highly resistant to mercury. The Illumina-based sequence analysis revealed a genome of approximately 4,520,353 bp composed of 4,091 coding sequences.

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Chemical investigation of the ethyl acetate extract from the endophytic fungus Diaporthe phaseolorum-92C (92C) isolated from the roots of Combretum lanceolatum led to the isolation of 18-des-hydroxy Cytochalasin H (compound 1). The trypanocidal and schistosomicidal activity and cytotoxicity of the extract from 92C were evaluated. The schistosomicidal, leishmanicidal, antimicrobial, and antioxidant actions, as well as the antitumor activity against the breast cancer cells MDA-MB-231 and MCF-7, and the cytotoxicity towards normal human lung fibroblasts GM07492A of compound 1 was tested.

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The compounds terrein (1), butyrolactone I (2), and butyrolactone V (3) were isolated from the ethyl acetate extract (EtOAc) of the endophytic fungus Aspergillus terreus-F7 obtained from Hyptis suaveolens (L.) Poit. The extract and the compounds presented schistosomicidal activity against Schistosoma mansoni; at 100 µg/mL for EtOAc extract, 1297.

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