Ethnopharmacological relevance Because of its virulence and antibiotic resistance, Staphylococcus aureus is a more formidable pathogen now than at any time since the pre-antibiotic era. In an effort to identify and develop novel antimicrobial agents with activity against this pathogen, we have examined Gynoxys verrucosa Wedd (Asteraceae), an herb used in traditional medicine in southern Ecuador for the treatment and healing of wounds. Materials and Methods The sesquiterpene lactones leucodine (1) and dehydroleucodine (2) were extracted and purified from the aerial parts of G. verrucosa, and their structure was elucidated by spectroscopic methods and single-crystal X-ray analysis. The in vitro anti-microbial activity of G. verrucosa extracts and its purified constituents was determined against six clinical isolates including S. aureus and Staphylococcus epidermidis strains with different drug-resistance profiles, using the microtiter broth method. Results Compound 1 has very low activity, while compound 2 has moderate activity with MIC50s between 49 and195 μg/mL. The extract of G. verrucosa has weak activity with MIC50s between 908 and 3290 μg/mL. Conclusions We are reporting the full assignment of the 1H-NMR and 13C-NMR of both compounds, and the crystal structure of compound 2, for the first time. Moreover, the fact that compound 2 has antimicrobial activity and compound 1 does not, demonstrates that the exocyclic conjugated methylene in the lactone ring is essential for the antimicrobial activity of these sesquiterpene lactones. However, the weak activity observed for the plants extracts, does not explain the use of G. verrucosa in traditional medicine for the treatment of wounds and skin infections.

The sesquiterpene lactones dehydroleucodine (1) and leucodine (2) were isolated from Gynoxys verrucosa, a species used in traditional medicine in southern Ecuador. The activity of these compounds was determined against eight acute myeloid leukemia (AML) cell lines and compared with their activity against normal peripheral blood mononuclear cells. Compound 1 showed cytotoxic activity against the tested cell lines, with LD50 values between 5.0 and 18.9 μM. Compound 2 was inactive against all of the tested cell lines, demonstrating that the exocyclic methylene in the lactone ring is required for cytotoxic activity. Importantly, compound 1 induced less toxicity to normal blood cells than to AML cell lines and was active against human AML cell samples from five patients, with an average LD50 of 9.4 μM. Mechanistic assays suggest that compound 1 has a similar mechanism of action to parthenolide (3). Although these compounds have significant structural differences, their lipophilic surface signatures show striking similarities.

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The COVID-19 pandemic required higher education institutions to change the modality of face-to-face to online learning overnight. Adaptations were needed, particularly in industrial process training in Chemical Engineering and related careers. Students could not access companies and industries for internships or industrial visits, intended to allow undergraduate students to observe the process engineers’ work in professional spaces. This paper describes a pedagogical strategy to overcome this limitation. Here, we report an approach applied in an Industrial Processes course, with students from the 8th to 10th semesters and alumni, from the undergraduate Petrochemical Engineering program at Yachay Tech University (Ecuador). In this course, the students developed group projects involving an industrial process analysis focused on economic sectors of interest in the country. The projects also included a revision of official figures and statistics on production data, consumption, and perspectives of the different markets. The execution of these projects promoted students’ active participation through technical discussions by exchanging ideas. A high level of attendance at synchronic classes reflected a high motivation. Through feedback and interviews, the students’ comments confirmed the relevance and value of the strategy applied in the course.

Dehydroleucodine is a bioactive sesquiterpene lactone. Herein, four dehydroleucodine amino derivatives were synthesized using the amines proline, piperidine, morpholine, and tyramine, and spectroscopic methods and single-crystal X-ray diffraction unambiguously established their structures. The cytotoxic activity of these compounds was evaluated against eight acute myeloid leukemia cell lines, and their toxicity to peripheral blood mononuclear cells was also determined. The proline adduct was the most active compound, it showed anti-leukemic activity, upregulated heme oxygenase 1 (HMOX1) and the primary stress-inducible isoform of the heath shock 70 kDa protein 1 (HSPA1A), and downregulated NFkB1 transcription, it was also found to be about 270 times more water soluble than dehydroleucodine.

A method to identify anticancer compounds in plants was proposed based on the hypothesis that these compounds are primarily present in plants to provide them with an ecological advantage over neighboring plants and other competitors. According to this view, identifying plants that contain compounds that inhibit or interfere with the development of other plant species may facilitate the discovery of novel anticancer agents. The method was developed and tested using Magnolia grandiflora, Gynoxys verrucosa, Picradeniopsis oppositifolia, and Hedyosmum racemosum, which are plant species known to possess compounds with cytotoxic activities. Plant extracts were screened for growth inhibitory activity, and then a thin-layer chromatography bioautography assay was conducted. This located the major antileukemic compounds 1, 2, 4, and 5 in the extracts. Once the active compounds were located, they were extracted and purified, and their structures were determined. The growth inhibitory activity of the purified compounds showed a significant correlation with their antileukemic activity. The proposed approach is rapid, inexpensive, and can easily be implemented in areas of the world with high biodiversity but with less access to advanced facilities and biological assays.

The COVID-19 pandemic has displayed new challenges for chemistry instructors and students worldwide. An essential part of learning chemistry involves interactions in a laboratory ambiance. However, nowadays, it is necessary to consider alternatives to teaching experimental chemistry in an online environment. As a course project proposal, the students produced homemade videos to investigate a specific topic and find alternative ways to transfer their knowledge through innovative pedagogical and communicational tools. This work was assigned to first-year undergraduate students in a Chemistry I course who could not access an on-campus laboratory. This activity was performed in eight lab sections, considering seven different lab assignments, with 56 homemade educational videos. Each course had an instructor who guided the students and gave their feedback to improve the video quality. The final video output was subjected to an evaluation process consisting of three steps: the instructors’ evaluation, pedagogical analysis, and communicational review. Making educational videos at home could be an excellent alternative to boost the transfer of chemistry knowledge through didactic and audiovisual resources that promote learning within the university, from home, and in remote environments.

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