• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.219-230
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• 2021

BACKGROUND: Biochar is a solid material converted from agricultural biomass such as crop residues and pruning branch through pyrolysis under limited oxygen supply. Biochar consists of non-degradable carbon (C) double bonds and aromatic ring that are not readily broken down by microbial degradation in the soils. Due to the recalcitrancy of C in biochar, biochar application to the soils is of help in enhancing soil carbon sequestration in arable lands that might be a strategy of agricultural sector to mitigate climate change. METHODS AND RESULTS: Data were collected from studies on the effect of biochar application on soil C content conducted in East Asian countries including China, Japan and Korea under different experimental conditions (incubation, column, pot, and field). The magnitude of soil C storage was positively correlated (p < 0.001) with biochar application rate under field conditions, reflecting accumulation of recalcitrant black C in the biochar. However, The changes in soil C contents per C input from biochar (% per t/ha) were 6.80 in field condition, and 12.58 in laboratory condition. The magnitude of increment of soil C was lower in field than in laboratory conditions due to potential loss of C through weathering of biochar under field conditions. Biochar production condition also affected soil C increment; more C increment was found with biochar produced at a high temperature (over 450℃). CONCLUSION: This review suggests that biochar application is a potential measures of C sequestration in agricultural soils. However, as the increment of soil C biochar was affected by biochar types, further studies are necessary to find better biochar types for enhanced soil C storage.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.225-231
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• 2021

Sesame seed oil cakes are classified as the animal or plant origin among the flammable liquids, and the fire occurs due to the spontaneous ignition through the accumulation of heat during the storage of residues after the extraction of sesame oil. In order to elucidate the cause of the spontaneous ignition of sesame seed oil cakes, the thickness (3 cm, 5 cm, 7 cm and 14 cm) of the sample container was varied, and the spontaneous ignition temperature was measured depending on the storage volume. Thus, the spontaneous ignition temperature was measured to be 180 ℃ at the thickness of 3 cm, 160 ℃ at 5 cm, 145 ℃ at 7 cm and 130 ℃ at 14 cm. As the thickness of the sample container increased, the critical ignition temperature decreased, and the induction time to spontaneous ignition and the time to reach the maximum temperature became longer. Furthermore, the apparent activation energy by the critical ignition temperature, which is the average temperature of ignition and non-ignition, was 97.10 [kJ/mol]. With these data, ignition characteristics of sesame seed oil cakes were determined.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.375-383
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• 2020

BACKGROUND: Bisphenol A (BPA) is a chemical widely used in polycarbonate plastics, epoxy resins. BPA is an endocrine disruptor. Residue of BPA in agricultural environments is a major concern. The objective of this study was to understand the characteristics of the uptake and distribution of BPA and its metabolites introduced into the agricultural environment to crops, and to use it as basic data for further research on reduction of BPA in agricultural products. METHODS AND RESULTS: This study established the analysis method of BPA and its metabolites in soil and crops, and estimated the intake of BPA and its metabolites from lettuce (Lactuca sativa) grown in sandy loam and loam soil, which are representative soils in Korea. The two major metabolites of BPA were 4-hydroxyacetophenone (4-HAP) and 4-hydroxybenzoic acid (4-HBA). BPA, 4-HAP and 4-HBA have been analyzed by using liquid chromatography tandem mass spectrometry (LC-MS/MS). These substances were detected in sandy loam and loam soil, indicating that certain portions of BPA were converted to 4-HAP and 4-HBA in the soil; however, it was observed that only 4-HBA migrated to lettuce through the roots into crops. CONCLUSION: The uptake residues showed the BPA and 4-HAP were not detected in lettuces grown on sandy loam (SL) and loam (L) soil treatments that were applied with of 10 ng/g, 50 ng/kg and 500 ng/g of BPA. However, the 4-HBA was detected at the level of 7 ng/g and 11 ng/g in the lettuce grown in sandy loam and loam soil that were treated with the 500 ng/g of BPA, respectively, while the 8 ng/g of 4-HBA was measured in the lettuce cultivated in the loam that was treated with 100 ng/g of BPA. This result presents that the BPA persisting in the soil of the pot was absorbed through the lettuce roots and then distributed in the lettuce leaves at the converted form of 4-HBA, what is the oxidative metabolite of BPA.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.239-244
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• 2021

In the present study, liquid chromatography tandem-mass spectrometry was used to conduct a risk assessment of ethoxyquin and ethoxyquin dimer residues in 288 farmed fish sold in wholesale and traditional markets in Seoul. The detection range (detection rate) of ethoxyquin and ethoxyquin dimer was 0.005~0.309 mg/kg (4.9%) and 0.001~2.828 mg/kg (69.8%), respectively. Ethoxyquin was detected only in freshwater eels, loaches, catfish, and flatfish, whereas ethoxyquin dimer was present in all fish species. To estimate the dietary exposure levels of ethoxyquin and ethoxyquin dimer, the hazard index, calculated using the acceptable daily intake and estimated daily intake, ranged from 0.001 to 0.300%. Our results indicate that there is no significant exposure risk to humans from these farmed fish despite 10 farmed fish samples exceeding the maximum residue level (1.0 mg/kg as the sum of ethoxyquin and ethoxyquin dimer).

• Journal of Food Hygiene and Safety
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• v.36 no.1
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• pp.9-16
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• 2021

The monitoring of residual pesticides in dried chili peppers and chili powders, which are circulated in Seoul from 2018 to 2019, was conducted for safety evaluation. As a result of analyzing for 71 kinds of pesticide residues in 101 cases of samples, pesticides were detected in 87 samples; however, no samples exceeded the MRLs (Maximum Residue Limits). Detection rates of pesticides in dried chili peppers and chili powders were 73.3% and 91.5%, respectively. The detection rate of residual pesticides in chili powders was a little higher than that in dried chili peppers. Twelve types of pesticides were detected, however, those pesticides were acceptable to use on peppers, according to the Crop Protection Guidelines. The most frequently detected pesticide was pyraclostrobin followed by flubendiamide, azoxystrobin, and chlorantraniliprole. The risk for detected pesticides was estimated as the ratio of ADI (Acceptable Daily Intake) to food intake rate. The ADI value resulting by intake of dried chili peppers and chili powders was in the range of 5.66E-05 to 3.34E-02, which was within a safe level.

• Biomolecules & Therapeutics
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• v.30 no.6
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• pp.553-561
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• 2022

Chronic myeloid leukemia (CML) is a slowly progressing hematopoietic cell disorder. Sphingosine kinase 1 (SPHK1) plays established roles in tumor initiation, progression, and chemotherapy resistance in a wide range of cancers, including leukemia. However, small-molecule inhibitors targeting SPHK1 in CML still need to be developed. This study revealed the role of SPHK1 in CML and investigated the potential anti-leukemic activity of hirsuteine (HST), an indole alkaloid obtained from the oriental plant Uncaria rhynchophylla, in CML cells. These results suggest that SPHK1 is highly expressed in CML cells and that overexpression of SPHK1 represents poor clinical outcomes in CML patients. HST exposure led to G2/M phase arrest, cellular apoptosis, and downregulation of Cyclin B1 and CDC2 and cleavage of Caspase 3 and PARP in CML cells. HST shifted sphingolipid rheostat from sphingosine 1-phosphate (S1P) towards the ceramide coupled with a marked inhibition of SPHK1. Mechanistically, HST significantly blocked SPHK1/S1P/S1PR1 and BCR-ABL/PI3K/Akt pathways. In addition, HST can be docked with residues of SPHK1 and shifts the SPHK1 melting curve, indicating the potential protein-ligand interactions between SPHK1 and HST in both CML cells. SPHK1 overexpression impaired apoptosis and proliferation of CML cells induced by HST alone. These results suggest that HST, which may serve as a novel and specific SPHK1 inhibitor, exerts anti-leukemic activity by inhibiting the SPHK1/S1P/S1PR1 and BCR-ABL/PI3K/Akt pathways in CML cells, thus conferring HST as a promising anti-leukemic drug for CML therapy in the future.

• Journal of Microbiology and Biotechnology
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• v.32 no.8
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• pp.1064-1071
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• 2022

Arabinogalactans have diverse biological properties and can be used as pharmaceutical agents. Most arabinogalactans are composed of β-(1→3)-galactan, so it is particularly important to identify β-1,3-galactanases that can selectively degrade them. In this study, a novel exo-β-1,3-galactanase, named PoGal3, was screened from Penicillium oxalicum sp. 68, and hetero-expressed in P. pastoris GS115 as a soluble protein. PoGal3 belongs to glycoside hydrolase family 43 (GH43) and has a 1,356-bp gene length that encodes 451 amino acids residues. To study the enzymatic properties and substrate selectivity of PoGal3, β-1,3-galactan (AG-P-I) from larch wood arabinogalactan (LWAG) was prepared and characterized by HPLC and NMR. Using AG-P-I as substrate, purified PoGal3 exhibited an optimal pH of 5.0 and temperature of 40℃. We also discovered that Zn²⁺ had the strongest promoting effect on enzyme activity, increasing it by 28.6%. Substrate specificity suggests that PoGal3 functions as an exo-β-1,3-galactanase, with its greatest catalytic activity observed on AG-P-I. Hydrolytic products of AG-P-I are mainly composed of galactose and β-1,6-galactobiose. In addition, PoGal3 can catalyze hydrolysis of LWAG to produce galacto-oligomers. PoGal3 is the first enzyme identified as an exo-β-1,3-galactanase that can be used in building glycan blocks of crucial glycoconjugates to assess their biological functions.

• Journal of Food Hygiene and Safety
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• v.37 no.3
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• pp.173-180
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• 2022

There are a number of methods to evaluate the quality of squid. However, when purchasing the fish, consumers and retails rely only on the sensory test and flavor in the field. Therefore, this study was aimed to prove relationship between scientific indicator and sensory test. Total viable cell count (TVC), viable cell count of Pseudomonas spp., pH and volatile basic nitrogen (VBN) were selected as scientific indicators and mesured during the storage of squid at different temperature. The squid was storaged at 3 different temperature (5℃, 15℃, 20℃). Off flavor determination time was measured by R-index, and kinetic modeling was conducted. Activation energies of off-flavor determination time, TVC, Pseudomonas spp, VBN, and pH were 51.210 kJ/mol, 42.88 kJ/mol, 50.283 kJ/mol, 72.594 kJ/mol and 41.99 kJ/mol respectively. Activation energy of off-flavor determination time was approximated to viable cell count of Pseudomonas spp., TVC, pH and VBN as an order. Especially, viable cell count of Pseudomonas spp. had best match of the activation energy. Therefore, it was judged that indicator of off-flavor determine time was viable cell count of Pseudomonas spp..

• KNOM Review
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• v.24 no.1
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• pp.29-37
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• 2021

With the spread of the Internet, users can easily receive various services and exchange information through the web. There are several requirements for building a web system, and it must be developed using a programming language or platform for user purposes. Residual material information refers to information on medicines and pesticides added to food, and residual material standards are used to measure the level of residues in food produced by companies and farmers to determine whether those levels meet domestic or international standards. Currently, the Ministry of Food and Drug Safety provides residual acceptance standards for food additives, including food, pesticides and animal medicines, in the form of documents, which must be serviced smoothly and conveniently by users through the establishment of a web system. It must also meet a variety of requirements, including user accessibility, such as scalability and compatibility. This paper proposes react-based residual material information web system that allows users to access more conveniently and receive residual material information smoothly. We measured the speed for the three inportant functions of information provision and compared them with existing residual material information web systems and qualitatively evaluated the seven essential requirements: scalability, compatibility, and accessibility.

• CELLMED
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• v.11 no.4
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• pp.21.1-21.9
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• 2021

Background: Unani System of Medicine (USM) has its origin to Greece. To ensure and develop the quality, authenticity of Unani drugs, standardization on modern analytical parameter is essential requirement for drugs. Objectives: The aimed of the present study was to develop a standard profile of "Qurṣ-e-Mafasil" by systematic study through authenticated ingredients, pharmacognostic identification followed by physicochemical, TLC, HPTLC fingerprinting analysis as per standard protocol. Material and Methods: In this study three batches of "Qurṣ-e-Mafasil" QM were prepared by standard method as per UPI had been followed by organoleptic properties of formulation such as appearance, color, odor, taste. Powder Microscopy and physicochemical studies were carried out such as Uniformity of weight, Friability, Disintegration time, hardness, LOD, ash vales and extractive values in like aqueous, alcohol & hexane. Further qualitative tests such as Thin-Layer Chromatography (TLC), and High-Performance Thin Layer Chromatography (HPTLC) studies were also carried out to develop fingerprint pattern of the alcoholic solvent extract of QM. Phytochemical screening was carried out in different solvent extracts such as alcoholic, aqueous and chloroform extracts to detect the presence phytoconstituents in the formulation QM. Heavy metals, Microbial Load Contamination and pesticidal residues were also determined. Results: Qurṣ-e-Mafasil showed tablet-like appearance, light brown colour, mild pungent odour and acrid taste. Uniformity of weight (mg), friability (rpm), and hardness (kg/cm) and disintegration time was ranged between (500 to 503), (0.0340 to 0.038), (8.40 to 8.67) and (4-5 minutes) respectively for the three batches. Loss in weight on drying at 105℃ was ranged between (8.3425 to 8.7346). Extracted values were calculated in distilled water ranged between (30.9091 to 31.4358), hexane (1.1419 to 1.4281), and alcohol (3.3352 to 3.3962). The ash values recorded were ranged between (3.7336 to 3.8378), and acid insoluble ash (0.5859 to 0.6112).