Sandra Neli Jimenez-Garcia

Current approaches for enhanced expression of secondary metabolites as bioactive compounds in plants for agronomic and human health purposes - a review.

The study of secondary metabolism in plants is an important source for the discovery of bioactive compounds with a wide range of applications. Today these bioactive compounds derived from plants are important drugs such as antibiotics, and agrochemicals substitutes, they also have been economically important as flavors and fragrances, dyes and pigments, and food preservatives. Many of the drugs sold today are synthetic modifications of naturally obtained substances. There is no rigid scheme for classifying secondary metabolites, but they can be divided into different groups based on their chemical components, function and biosynthesis: terpenoids and steroids, fatty acid-derived substances and polyketides, alkaloids, phenolic compounds, non-ribosomal polypeptides and enzyme cofactors. The increasing commercial importance of these chemical compounds has resulted in a great interest in secondary metabolism, particularly the possibility of altering the production of bioactive plant metabolites by means of tissue culture technology and metabolomics. In today’s world the use of bioactive compounds derived from plants plays an important role in pharmaceutical applications. This review presents information about these metabolites and their applications as well as their importance in agronomy and bioactive effects on human health as nutraceuticals. This review includes also the new tendencies to produce these bioactive compounds under different stresses conditions such as biotic and abiotic stress that could be included in production systems.

Elicitor Mixtures Significantly Increase Bioactive Compounds, Antioxidant Activity, and Quality Parameters in Sweet Bell Pepper

Sweet bell peppers are greatly appreciated for their taste, color, pungency, and aroma. Additionally, they are good sources of bioactive compounds with antioxidant activity, which can be improved by the use of elicitors. Elicitors act as metabolite-inducing factors (MIF) by mimic stress conditions. Since plants rarely experience a single stress condition one by one but are more likely to be exposed to simultaneous stresses, it is important to evaluate the effect of elicitors on plant secondary metabolism as mixtures. Jasmonic acid (JA), hydrogen peroxide (HP), and chitosan (CH) were applied to fruits and plants of bell pepper as mixtures. Bioactive compounds, antioxidant activity, and quality parameters were evaluated. The assessed elicitor cocktail leads to an increase in the variables evaluated (P ≤ 0.05) when applied to mature fruits after harvest, whereas the lowest values were observed in the treatment applied to immature fruits. Therefore, the application of the elicitor cocktail to harvested mature fruits is recommended in order to improve bioactive compounds and the antioxidant activity of sweet bell peppers.

Strategies for Sustainable Plant Food Production: Facing the Current Agricultural Challenges—Agriculture for Today and Tomorrow

Plants are fundamental elements of the human diet, either as direct sources of nutrients or indirectly as feed for animals. During the past years, the main goal of agriculture has been to increase yield in order to provide the food that is needed by a growing world population. However, as important as yield, but commonly forgotten in conventional agriculture, is to retain and, if possible, to increase the phytochemical content due to their health implications. By 2025, the global population will exceed 7 billion. In the short term, per capita availability of arable land and irrigation water will decrease from year to year while biotic and abiotic stresses expand. Food security, defined as economic, physical, and social access to a balanced diet and harmless drinking water will be a compromise, with a holistic approach to nutritional and non-nutritional factors needed to achieve success in the eradication of hunger. Science and technology will play a very important role in stimulating and sustaining agriculture leading to long-term increases in productivity without linked ecological harm.

Influence of hydrogen peroxide foliar applications on in vitro antimicrobial activity in Capsicum chinense Jacq.

Abstract The aim of this study was to evaluate the effect of foliar applications of hydrogen peroxide on the antimicrobial activity of Capsicum chinense Jacq. methanolic extracts. The effects of hydrogen peroxide application on metabolites accumulation of C. chinense var. Jaguar and var. Chichen Itza were evaluated. Total flavonoid and phenolic contents, as well as HPLC quantification of capsaicin and dihidrocapsaicin were carried out. Methanolic extracts were microbiologically tested against Staphylococcus aureus, Escherichia coli, Streptococcus mutants, Salmonella thompson, Listeria monocytogenes, Streptococcus faecalis, and Candida albicans. Total phenolics, flavonoids, and capsaicinoids contents in both varieties treated with hydrogen peroxide were found significantly higher as compared to control. The antibacterial activity of chili extracts was observed against Gram-positive and Gram-negative bacteria as well as anti-yeast. The results of in vitro antibacterial activity showed that hydrogen peroxide application increases the inhibitory effect against the pathogenic micro-organisms. Methanolic extracts of var. Jaguar, were the most active against S. aureus, S. Thompson, and C. albicans, while var. Chichen Itza was most potent against E. faecalis and E. coli. Thus, this study confirmed that metabolite-induced factors (MIFs) as hydrogen peroxide, increased secondary metabolites accumulation in C. chinense methanolic extracts and augmented their antimicrobial activity.