Adjusting RT-qPCR conditions to avoid unspecific amplification in SARS-CoV-2 diagnosis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in December 2019 and quickly spread around the world, forcing global health authorities to develop protocols for its diagnosis. Here we report dimer formation in the N2 primers-probe set (CDC 2019-nCoV Real-Time RT-PCR) used in the diagnostic routine, and propose alternatives to reduce dimerization events. Late unspecific amplifications were visualized in 56.

Aspidosperma species as sources of anti-malarials: uleine is the major anti-malarial indole alkaloid from Aspidosperma parvifolium (Apocynaceae).

Background: Several species of the genus Aspidosperma (Apocynaceae) are used for the treatment of human malaria in Brazil and other meso- and South American countries.

Methods: Ethanol extract from Aspidosperma parvifolium trunk bark was submitted to acid-base extractions leading to alkaloid and neutral fractions. The alkaloid fraction was chromatographed over a silica gel column.

Potential cytotoxic activity of some Brazilian seaweeds on human melanoma cells.

In vitro screening of the crude extracts of some Brazilian coastal seaweeds for cytotoxic activity against a cultured human melanoma cancer cell line using the sulphorhodamine B assay was performed. The crude dichloromethane:chloroform extract of Stypopodium zonale showed good cytotoxic activity against the C32 cell line. The crude acetone extract and aqueous phase of Lobophora variegata did not show any activity, but semi-purified fractions XAD LOB I and II could inhibit the growth of melanoma cells.