MIXTURE DESIGN AND OPTIMUM REGION VISUALIZATION WITH SPREADSHEETS AT EXCEL: A TUTORIAL. This tutorial shows how to perform the data treatment for mixture design with two and multiple responses. Two data sets from the literature were used to exemplify the calculations. A template in Excel was proposed to prepare contour plot and response surface to visualize the optimum region of the mixture, which usually is made with commercial computational programs. The desirability function was used in example 2 (optimization of 5 responses simultaneously), and a code also available for download was proposed. Besides, 21 videos were prepared to show all the details for the readers and, it is available on YouTube. With this tutorial, it is possible to learn in a practical fashion how to handle the data from mixture design and, the authors hope to contribute with the researchers in this area.

The chemical investigation of ethyl acetate extract from Paepalanthus planifolius capitula resulted in the identification of 1H-naphtho[2,3-c]pyran-1-one,9-[(6-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy]-3,4-dihydro-10-hydroxy-7-methoxy-3-methyl, semi-vioxanthin 9-O-β-D-glucopyranoside, toralactone-9-O-β-D-glucopyranoside, paepalantine-9-O-β-D-glucopyranoside, semi-vioxanthin, 1H-naphtho[2,3-c]pyran-1-one,3,4-dihydro-9,10-dihydroxy-5,7-dimethoxy-3-methyl, vioxanthin and paepalantine dimer, and also the isolation and identification of a new naphthopyranone dimer named planifoliusin A. The chemical structures of two compounds were elucidated by performing spectroscopic 1D and 2D nuclear magnetic resonance (NMR) experiments and spectrometric HRMS (high-resolution mass spectrometry) analysis. Other six naphthopyranone dimers were proposed by MS fragmentation patterns. The minimum inhibitory concentration (MIC) values for vioxanthin (7.8 µg mL-1), planifoliusin A (15.6 µg mL-1) and the ethyl acetate extract (31.2 µg mL-1) showed antimicrobial activity against Staphylococcus aureus (ATCC 25923).

The screening for antimicrobial activity of twenty five endophytic fungi isolated from the aerial parts of Paepalanthus chiquitensis (Eriocaulaceae) was assayed against the bacteria Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli and Salmonella setubal, and the yeast fluconazole-resistant Candida albicans. The ethyl acetate extract produced by Fusarium fujikuroi was the most bioactive and this fungus was chosen for the chemical study, affording the isolation of an alkaloid 2-(4-butylpicolinamide) acetic acid and three known metabolites: fusaric acid, indole acetic acid and the sesterterpene terpestacin. The minimal inhibitory concentration of the extract and of fusaric acid and indole acetic acid for all the tested microorganisms had values from 125 to 1000 µg mL-1.