Browsing by Autor "Kelly E. Loayza Afonso"

Now showing 1 - 4 of 4

A SCREENING FOR ANTIOXIDANT SPECIES WITH PHOTO-PROTECTOR ACTIVITIES AT THE ZONGO VALLEY (BOLIVIA)
(2019) Sandra L. Ibáñez-Calero; Kelly E. Loayza Afonso
Eleven plants were collected at the Zongo Valley to evaluate their antioxidant and photo-protector properties. In this paper we report a strong correlation between high antioxidant activity and strong UV-A and/or UV-B absorptions. The most active species, tested at 10µg/ml with the DPPH assay, were Fuchsia boliviana (leaves), Baccharis pentlandii (flowers), Rubus floribundus (fruits), Fuchsia boliviana (flowers and fruits) and Brachyotum microdon (flowers). All the mentioned species have important UV- B and/or UV-A absorptions. This DPPH/UV technique could be used to preliminary screen vegetable samples and to select those with DPPH values above 83% and strong UV-A and/or UV-B absorptions. The chosen samples can then be evaluated with other more expensive in vitro assay (TEAC, ABTS or FRAP) to finally confirm their activities with the in vivo test. To our knowledge, this is the first time that the antioxidant properties of Distichia muscoides, Souroubea fragilis, Brachyotum microdon, Monnina bridgesii, Baccharis pentlandii, Thibaudia crenulata, Siphocampylus tupaeformis, Cobaea scandens, Fuchsia boliviana and Rubus floribundus are reported. In addition, this is the first time that Siphocampylus tupaeformis and Thibaudia crenulata are presented in a publication as well as the study of their photo-protector and antioxidant properties.
A SCREENING FOR NATURAL COLORANTS IN THE ZONGO VALLEY WITH PROBABLE ANTIOXIDANT AND/OR PHOTO-PROTECTOR ACTIVITIES
(2016) Sandra L. Ibáñez-Calero; Kelly E. Loayza Afonso; Ebbe L. Yapu Tapia; Jessica Lizarazu; Rodrigo Zeballos Espinoza; Teddy Solares Gironda
Eleven plants were collected in the Zongo Valley following an organoleptic and chimio-taxonomic criteria of collection to find species with colorant and photo-protector properties. Brachyotum microdon, Monnina bridgesii and Souroubea fragilis present promising colorant attributes. In addition, B. microdon, Rumex acetosella and Fuchsia boliviana show important absorptions in the UV-B region while S. fragilis, Orthaea boliviensis, Senecio floccosus and Baccharis pentlandii have UV-A and UV-B absorptions. A series of phytochemical tests were performed to learn about the secondary metabolite profile in the collected species. This is the first work done and published for Souroubea fragilis, Orthaea boliviensis and Senecio floccosus.
A SCREENING FOR NATURAL COLORANTS IN THE ZONGO VALLEY WITH PROBABLE ANTIOXIDANT AND/OR PHOTO-PROTECTOR ACTIVITIES
(2016) Sandra L. Ibáñez-Calero; Kelly E. Loayza Afonso; Ebbe L. Yapu Tapia; Jessica Lizarazu; Rodrigo Zeballos Espinoza; Teddy Solares Gironda
Eleven plants were collected in the Zongo Valley following an organoleptic and chimio-taxonomic criteria of collection to find species with colorant and photo-protector properties. Brachyotum microdon, Monnina bridgesii and Souroubea fragilis present promising colorant attributes. In addition, B. microdon, Rumex acetosella and Fuchsia boliviana show important absorptions in the UV-B region while S. fragilis, Orthaea boliviensis, Senecio floccosus and Baccharis pentlandii have UV-A and UV-B absorptions. A series of phytochemical tests were performed to learn about the secondary metabolite profile in the collected species. This is the first work done and published for Souroubea fragilis, Orthaea boliviensis and Senecio floccosus.
COLORANTES NATURALES DEL VALLE DE ZONGO (BOLIVIA) Y SUS APLICACIONES TEXTILES
(2020) Sandra L. Ibáñez-CaleroIbáñez-Calero; Kelly E. Loayza Afonso
Three plants collected at the Zongo Valley were evaluated for textile dyeing applications. The species selected were extracted following acidic and basic procedures to obtain colored samples, that were submitted to direct and indirect (with mordents) dyeing techniques. In all experiments the need of a mordant was observed and the type of chemical mordant was identified. In each work, the strength of the fabric’s dye with the natural colorant was evaluated using a series of washing, rinsing, drying, ironing and exposure to sun light protocols. It was found that the acidic extract of Brachyotum microdon (flowers) needs Al2(SO4)3 to dye the fabric with a red cabernet tone, while the basic extract fixes the fabric with a brown color with FeCl3 and green with FeSO4. The acid extract of the stems of Souroubea fragilis dyed the fabric with a light orange color when Al2(SO4)3 was used as a mordent, while the basic extract provided brown tones thanks to CuSO4 or FeSO4. Finally, the acidic extract of Fuchsia boliviana (flowers and fruits) gave a pale rose and a green tinting with Al2(SO4)3 and FeCl3, respectively. The basic extract of this plant provided a green dyeing with CuSO4 and orange shading with FeCl3. Different types of fabrics were evaluated, and the best dyeing results were observed with cotton. All the extracts studied presented antioxidant and photoprotector activities. The acidic extract of Brachyotum microdon (flowers) showed 82.5% of inhibition at 10µg/ml against DPPH and it absorbed the harmful UV B radiation. The acidic extract of Fuchsia boliviana (flowers and fruits) gave an 86.7% of inhibition at 10µg/ml against DPPH and it also absorbed the damaging UV B radiation. Finally, the acidic extract of Souroubea fragilis (stems) presented 92.1% of inhibition at 100µg/ml against DPPH and it absorbed both UV-B and UV-A radiations.