Agri-foods as well as environmental safety are major concerns of the modern society. Pesticides are indispensable agents to control pests and weeds in modern agriculture. A pesticide must have a certain degree of toxicity and persistence to have a control effect suitable for its purpose. However, pesticides must also quickly decompose into non-toxic substances following their activity to avoid residual toxicity in the environment or on crops. Environmental homeostasis includes mechanisms to detoxify hazardous substances including pesticides, over time. Some pesticides sprayed on arable soil remain in the soil and can be transferred to the succeeding rotational crops via their roots. This is problematic under the positive list system if the cultivation standards for rotational crops do not consider the possibility of residual pesticides in arable soil, and consider only pesticide sprayed on the crops. Therefore, tracking the fate of applied pesticides in the environment is important for environmental protection and for safety evaluation of agri-foods.
In this presentation, I briefly summarize with three parts our recently published results. I hope that this presentation will be a reference for researchers who are majoring in pesticide chemistry or want to conduct research on pesticides.
1. Environmental remediation mechanisms for pesticide detoxification through oxidative coupling reaction.
2. Research on the establishment of pesticide residue standards in cultivated soil through studies on the mechanism of crop absorption.
3. Studies on the residual characteristics of pesticides in agri-food to establish safety evaluation standards.

Microbial biofilms and environmental pollution are considered to be a major concern for human health worldwide. Microbial invasions cause a range of diseases such as tuberculosis, candidiasis, streptobacillary rat-bite fever, chickenpox, AIDS, COVID 19, Hepatitis, etc., on the other hand, the environmental pollutions lead the serious health impact by causing the diseases such as arthritis, cancer, diabetes, reproductive, and neurological diseases. The current interest is in understanding the biology, and biotechnology of the infectious disease related to the microbial biofilms and environmental pollution would protect the human life from deadly diseases. Therefore, our research group has worked on the development of engineered nanomaterials and natural products to cure deadly diseases as well as secure a healthy environment for human life. For the instance, our group has recently reported several inorganic and organic nanoparticles with promising anticancer, antioxidant, antibacterial, and bioremediation properties. Also, we are developing the polymers and liposomes-based drug delivery system for the improved therapeutic activity of the natural products for the treatment of several chronic diseases including diabetes, cancer, and bacterial infections.
Keywords Nanoparticles, pollution, natural products, microbial biofilms

The agricultural fields have been gaining concerns of occurrence and dispersion of antibiotic-resistant microorganisms. As consumption of antibiotics is considered a major driver of antibiotic resistance, this study determined tetracycline resistance and multidrug resistance among the tetracycline-resistant bacterial isolates from two agricultural soil conditions. The first setting involved activities with direct administration of antibiotics as feed additives for animal health in animal houses, whereas the second was exposed to antibiotics primarily as a consequence of favorable agricultural practices of using composted manure in crop-farming soils. The ratio of total culturable tetracycline-resistant bacteria to total culturable bacteria indicated that the highest ratio of tetracycline-resistant bacteria from animal house soils (0.30) was higher than that from agricultural soils (0.20). On the other hand, the most frequently detected ribosomal protection protein (RPP) tetracycline resistance tet gene was found to be tet, which was detected in 16 sites from the total 18 agricultural sites, followed by tet and tet, whereas tet was the least detected tet gene. Three compost samples were also found to be positive for tet, tet, and tet genes. The quantified copy numbers of each tet gene per gram of soil showed that tet was the most abundant among the three quantified RPP tet genes and observed to be higher in agricultural soils than animal house soils. Antibiotic susceptibility testing results revealed that some of the bacterial isolates were multidrug-resistant to commonly used antibiotics in agriculture. Identification of the bacterial isolates exhibiting the multidrug resistance would be important in assessing the risk to human health, and also could hint the possible sources that would be crucial to understanding the ecology of antibiotic resistance, which in turn would help in creating measures to hinder or prevent its rapid transmission. High prevalence and high quantified copy number of antibiotic resistance gene might be indicative of its inclusion for surveillance.

It is estimated that more than a million metabolites are biosynthesized in the plant. Theses metabolite composition are different depending on various factor such as cultivar, postharvest treatment, and maturity etc. Among the metabolites, it was reported that phenolic metabolites have antioxidative, anticarcinogenic, and anti-inflammatory effect. These health benefit effects are resulted from metabolites of phenolics produced in human body. Thus, to understand health benefit effect from food, it is important to understand the difference of phenolic metabolite composition depending on environmental variable and information of metabolite composition resulted from phenolics during digestion in human body. Metabolomics is a science to study the whole metabolome in a given system, it is being more used in the different fields of life science such as functional genomics, quality control of medicinal plant or crop management etc. Ultra-high performance liquid chromatography (UHPLC) or gas chromatography (GC) coupled with mass spectrometry (MS) is a powerful tool to perform global profiling of small molecules (metabolites) in various sample. In this presentation, phenolic metabolite composition in various foods rich in phenolics will be presented. Furthermore, metabolites of phenolics will be presented in vitro model.

Broussonetia papyrifera (L.) L Her. ex Vent. (paper mulberry), in the family Moraceae, are used as a traditional medicine in Korea, and its biological activities such as diuretic, tonic, and suppressant for edema have been reported. In this study, twenty flavonoids were isolated from the root bark of B. papyrifera based on bioactivity-guided separation, and evaluated their biological activities. The isolated flavonoids, including new derivatives reported firstly were identified on the basis of spectroscopic data (1D and 2D NMR, MS, MS/MS, and HRMS). Each of isolated flavonoids was evaluated for the inhibitory activities for anti-inflammatory activity in RAW264.7 cell, AMPK in 3T3-L1 adipocyte, and anti-neuraminidase activity. Their inhibition mechanisms were ascertained by the suppression of cytokine expression/production and enzyme kinetic plots. Therefore, this study suggests that the extract of B. papyrifera root bark and isolated compounds could be valuable sources for the development of pharmaceuticals or functional foods by the effects of anti-inflammation, anti-obesity, antidiabetic activity, and anti-neuraminidase activity.