Evaluation of Potato Varieties with High Antioxidant Activities by Measuring Phenolic Acids in Different Tuber Parts

Kui-Hua Li,Eung-Jun Park,Hoi-Seon Lee,Dong-Man Khu,Stephen L. Love,Hak-Tae Lim 한국원예학회 2006 Horticulture, Environment, and Biotechnology Vol.47 No.3

Potato is a valuable source of antioxidants in the human diet and their genetic variability exists for antioxidant activity. This study was carried out to define selection criteria for potato varieties and breeding clones with high antioxidant levels as measured by 1,1-diphenyl-2-picryl-hydrazyl methods. There were significant differences in antioxidant activities among potato genotypes. Radical scavenging activities (RC??) of 29 potato genotypes ranged from 64.8 to 493.6 ㎍ㆍmL?¹. We further analyzed the antioxidant activities in three different sections including cortex, perimedullary, and pith tissue were separately measured for five selected potato varieties. At least, two-fold higher antioxidant activity for cortex tissue (5 ㎜-thick of periderm tissue with skin) was found in all five ‘Valley’ potatoes, compared to that in ‘Atlantic’. Very low antioxidant activity was detected in perimedullary and pith tissue of all potato varieties, except for ‘Bora Valley’, which had purple flesh. Based on the varieties tested, purple skinned varieties showed higher antioxidant activity than red skinned tubers, while tubers with yellow skins showed the lowest antioxidant activity. The levels of three major phenolic compounds such as chlorogenic, caffeic, and ferulic acids were highly correlated to RC50 values for cortex tissue as well as whole tubers. Although chlorogenic, caffeic, and ferulic acids were the major phenolic acids contributing to the total antioxidant activity of potato tubers, caffeic acid was the most effective compound contributing to the total tuber antioxidant activity based on RC?? values.

Frequent Mutations of p53 and MTS1/CDK4I Tumor Suppressor Genes in Chinese Preneoplastic and Neoplastic Oral Tissues

Li, Sheng-Lin,Baek, Jeong-Hwa,Zhang, Kui-Hua,Min, Byung-Moo,Gujuluva, Chandrasekhar N.,Bertolami, Charles N.,Park, No-Hee Korean Academy of Oral Biology and the UCLA Dental 1996 International Journal of Oral Biology Vol.21 No.1

Aberrant expression and mutation in the p53 and MTS1/CDK41 genes were determined from 11 normal, 8 preneoplastic and 25 neoplastic oral tissues obtained from Beijing, China, using immunostaining, single strand conformational polymorphism analysis, and nucleotide sequencing. Normal tissue showed a negligible amount of p53 immunostaining, while 3 (38%) of 8 preneoplastic, and 16 (64%) of 25 cancer tissues demonstrated moderate to strong p53 immunostaining. Point mutations within exons 5 to 8 were not detected in normal tissue specimens, but were detected in 2 (25%) preneoplastic tissues and in 15 (60%) cancer specimens. OF the tissues with mutations, 2 (100%) preneoplatic and 14 (93%) cancer tissues contained a CGT to CAT mutation at codon 273 of p53 gene. One cancer tissue showed a silent mutation (CGC to CTC) at codon 283. Three cancer specimens containing a point mutation at codon 273 also showed additional silent mutations at codons 156, 157, or 275. These data indicate that p53 mutation is highly prevalent in tested preneoplastic and neoplastic oral tissues and that the codon 273 is the "hot-spot" for point mutations. The enhanced p53 immunostaining was, in general, closely associated with point mutations, but 1 (13%) preneoplastic sample and 5 (20%) neoplastic oral tissues not containing point mutations within exons 5 to 8 demonstrated enhanced immunostaining. Over 62% of preneoplastic and 80% of neoplastic oral tissues contained mutations in MTS1/CDK4I gene, but, unlike p53 mutations, the mutation pattern of MTS1/CDK4I gene was not specific. Two preneoplastic (25%) and 12 neoplastic (48%) tissues contained mutations in both p53 and MTS1/CDK4I genes, and 2 preneoplastic (25%) and 3 neoplastic (12%) tissues contained mutations neither in p53 nor in MTS1/CDK4I genes.

A Novel Non-phosgene Approach to the Synthesis of Methyl N-phenyl Carbamate by a Reaction of Methanol with Phenylurea

Wang, Xin-kui,Yan, Shi-run,Li, Zhen-hua,Fan, Kang-nian,Kang, Mao-qing,Peng, Shao-yi 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.2

A novel non-phosgene process for the synthesis of methyl N-phenyl carbamate (MPC) by a reaction of phenylurea with methanol was studied. The reaction between phenylurea and methanol was found to be a spontaneous reaction that took place in the absence of catalyst and gave MPC as the main product. Addition of a catalyst markedly influenced the reaction behavior. A basic catalyst greatly enhanced the yield of MPC, whereas an acidic catalyst promoted the formation of aniline and methyl carbamate. Moderate strength of basicity showed the best catalytic performance in the cases studied. The mechanism of reaction and catalyst functioning was discussed.

Microstructure and viscoelastic behavior of waterborne polyurethane/cellulose nanofiber nanocomposite

Hui Zhao,Kui-Can Li,Wei Wu,Qing Li,Yan Jiang,Bing-Xu Cheng,Chong-Xing Huang,Hua-Nan Li 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.110 No.-

Cellulose nanofiber (CNF) has been widely used to reinforce the mechanical properties of waterbornepolyurethane (WPU). There are, however, few works that focus on structure, rheological behavior, andcreep resistance of WPU/CNF composites. To fill this research gap, in this work, the m-CNF was obtainedby c-aminopropyltriethoxysilane modification to improve the interfacial strength of CNF and WPU, andthen it was introduced into the polyurethane matrix. Structure characterization of WPU/m-CNFnanocomposites is performed using Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction(XRD), Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The obtainedresults show that with the increase of m-CNF, the hydrogen bonding index (HBI) increased, which meanta significant improvement in the mechanical properties. The tensile strength improved by 480%. Moreover, with the increase of m-CNF content, the viscosity, storage modulus, and loss modulus of thedispersions increased and showed more obvious shear-thinning behavior. In addition, m-CNF improvedthe thermal stability and creep resistance of WPU. The creep strain of WPU decreased from 3% to 0.2%. This work offers a simply feasible way to prepare environmental friendly green nanocomposites.

Energy Storage of Polyarylene Ether Nitriles at High Temperature

Xiaohe Tang,Yong You,Hua Mao,Kui Li,Renbo Wei,Xiaobo Liu 대한금속·재료학회 2018 ELECTRONIC MATERIALS LETTERS Vol.14 No.4

Polyarylene ether nitrile (PEN) was synthesized and used as film capacitors for energy storage at high temperature. Scanningelectron microscopy observation indicated that the films of PEN have pinholes at nanoscales which restricted the energystorage properties of the material. The pinhole shadowing effect through which the energy storage properties of PEN wereeffectively improved to be 2.3 J/cm3 was observed by using the overlapped film of PEN. The high glass transition temperature(Tg) of PEN was as high as 216 °C and PEN film showed stable dielectric constant, breakdown strength and energy storagedensity before the Tg. The PEN films will be a potential candidate as high performance electronic storage materials used athigh temperature.

Gene cloning and functional analysis of yellow green leaf 3 (ygl3) gene during the whole-plant growth stage in rice

Xiaoqing Tian,Ying-Hua Ling,Li-kui Fang,Peng Du,Xian-Chun Sang,Fang-Ming Zhao,Yun-Feng Li,Rong Xie,Guang-Hua He 한국유전학회 2013 Genes & Genomics Vol.35 No.1

Chlorophyll is an important photosynthetic pigment in the process of photosynthesis in plants and photosynthetic bacteria. Genes involved in chlorophyll biosynthesis in Arabidopsis and photosynthetic bacteria have been well documented. In rice, however, these genes have not been fully annotated. In this paper, a yellow-green leaf gene, yellow green leaf3 (ygl3) was cloned and analyzed. ygl3 encodes magnesium chelation ChlD (D) subunit,a key enzyme for chlorophyll synthesis, resulting in a yellow-green leaf phenotype in all growth stages in rice. Expression content of ygl3 is highest in the leaf blades,followed by the leaf sheaths, while there is virtually no expression of the gene in the stems and seeds. The subcellular structure and protein content of the photosynthetic system of the ygl3 mutant were revealed by transmission electron microscopy, BN-PAGE, and western blotting. The results show that the mutation of the ygl3 gene indirectly leads to a decrease in the protein content of the photosynthetic system and severely obstructs the formation of granum thylakoids.

Construction and Cloning of the Rc/CMV-GFP Fluorescence Expression Vector

Wang, Yi-Xiang,Li, Sheng-lin,Fu, Jia,Zhang, Kui-hua Korean Academy of Oral Biology and the UCLA Dental 2000 International Journal of Oral Biology Vol.25 No.1

A plasmid that can express fluorescence in prokaryotic and eukaryotic cells, RC/CMV-GFP was constructed by cloning the green fluorescent protein gene〔gfp〕into the Rc/CMV expression vector. The green fluorescent protein 〔GFP〕was expressed in E. coli JM109〔Rc/CMV-FGP〕, and green light was emitted under UV irradiation. Thus, this vector can be used to label oral microorganisms or tumor cells for studies of their biological behavior.

Physiological character and molecular mapping of leaf-color mutant wyv1 in rice (Oryza sativa L.)

Xian-chun Sang,Li-kui Fang,Yuenyong Vanichpakorn,Ying-hua Ling,Peng Du,Fang-ming Zhao,Zheng-lin Yang,Guang-hua He 한국유전학회 2010 Genes & Genomics Vol.32 No.2

The seed of an excellent indica restorer line Jinhui10 (Oryza sativa L. ssp. indica) was treated by ethyl methanesulfonate (EMS); a leaf-color mutant displaying distinct phenotype throughout development grown in paddy field was identified from the progeny. The mutant leaf showed white-yellow at seedling stage and then turned to yellow-green at tillering stage, after that, virescent color appeared until to maturity. The mutant was thus temporarily designed as wyv1. The chlorophyll contents decreased significantly and the changing was consistent with the chlorotic level of wyv1 leaves. Chlorophyll fluorescence kinetic parameters measured at the seedling stage showed that co-efficiency of photochemical quenching (qP),actual photosystem II efficiency (ΦPS II), electron transport rate (ETR) and initial chlorophyll fluorescence level (Fo), net photosynthetic rate (Pn) and maximum photochemical efficiency (Fv / Fm) significantly decreased in severe chlorotic leaf of the mutant compared with that of wild type. However,no significant differences were observed for Pn and Fv/Fm between virescent leaf and normal green leaf. Genetic analysis suggested that the mutant phenotype was controlled by a single recessive nuclear gene which was finally mapped between SSR marker Y7 and Y6 on rice chromosome 3 based on F2 population of Xinong1A / wyv1. Genetic distances were 0.06 cM and 0.03 cM respectively, and the physical distance was 84kb according to the sequence of indica rice 9311. The results must facilitate map-based cloning and functional analysis of WYV1 gene.

A Novel Non-phosgene Approach to the Synthesis of Methyl N-phenyl Carbamate by a Reaction of Methanol with Phenylurea

Shi-run Yan,Xin-kui Wang,Zhen-hua Li,Kang-nian Fan,Mao-qing Kang,Shao-yi Peng 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.2

A novel non-phosgene process for the synthesis of methyl N-phenyl carbamate (MPC) by a reaction of phenylurea with methanol was studied. The reaction between phenylurea and methanol was found to be a spontaneous reaction that took place in the absence of catalyst and gave MPC as the main product. Addition of a catalyst markedly influenced the reaction behavior. A basic catalyst greatly enhanced the yield of MPC, whereas an acidic catalyst promoted the formation of aniline and methyl carbamate. Moderate strength of basicity showed the best catalytic performance in the cases studied. The mechanism of reaction and catalyst functioning was discussed.

Identification and characterization of differentially expressed miRNAs between bamboo shoot and rhizome shoot

Qun-Ying Jin,Hua-Zheng Peng,Er-Pei Lin,Nan Li,Dan-Ni Huang,Yan-Li Xu,Xi-Qi Hua,Kui-Hong Wang,Tang-Jun Zhu 한국식물학회 2016 Journal of Plant Biology Vol.59 No.4

As one of the largest members of Poaceae family, bamboo is a very important agricultural plant in the world. The development of bamboo shoot is very special and particularly significant to bamboo production. Understanding the developmental differences between bamboo shoot and rhizome shoot is extremely valuable for us to further elucidate the mechanism of bamboo shoot formation since both bamboo shoot and rhizome shoot develop directly from rhizome bud underground. In this paper, miRNA chips with 413 miRNA probes were used to compare miRNA expressions between bamboo shoot and rhizome shoot. The experiment revealed 64 bamboo shoot upregulated and 56 rhizome shoot up-regulated miRNAs which were classified into four major categories according to deep sequencing based target prediction. Meristem and morphological development related miRNAs were most important in bamboo shoot, especially miR171 and miR156 members. While in rhizome shoot the mainstream of miRNA expressions was metabolism and nutrition related ones, especially miR395 members. The meristem and morphological development related miRNAs in bamboo shoot showed some embryonic characteristics and suggested the participation of several phytohormones like gibberellin, cytokinin and auxin, which were absent in those miRNAs of rhizome shoot. Further qRT-PCR detections of 21 up-regulated miRNAs in bamboo seedlings indicated that 12 ones were regulated to varying degrees by some environmental factors. Among them, rhizome shoot upregulated osa-miR395b was the most environment-sensitive miRNA, particularly to dehydration. And the bamboo shoot up-regulated osa-miR399j proved uniquely and strongly induced by phosphor. The existence of multiple regulation sites from same miRNA suggested the probability of crosstalks among meristem development, metabolism and stress response during bamboo shoot and rhizome shoot development.