المؤلفون: Hayato Ishikawa, Mariko Kitajima, Sho Imaoka, Yuta Nakashima

المصدر: Chemical and Pharmaceutical Bulletin. 2024, 72(1):68

المؤلفون: Morihiro Oota, Syuuto Toyoda, Toshihisa Kotake, Naoki Wada, Masatsugu Hashiguchi, Ryo Akashi, Hayato Ishikawa, Bruno Favery, Allen Yi-Lun Tsai, Shinichiro Sawa

المصدر: Frontiers in Plant Science, Vol 13 (2023)

مصطلحات موضوعية: root-knot nematodes (Meloidogyne incognita), super roots, chemotaxis, pectin, Lotus corniculatus L., Plant culture, SB1-1110

الوصف: IntroductionThe soil houses a tremendous amount of micro-organisms, many of which are plant parasites and pathogens by feeding off plant roots for sustenance. Such root pathogens and parasites often rely on plant-secreted signaling molecules in the rhizosphere as host guidance cues. Here we describe the isolation and characterization of a chemoattractant of plant-parasitic root-knot nematodes (Meloidogyne incognita, RKN).MethodsThe Super-growing Root (SR) culture, consisting of excised roots from the legume species Lotus corniculatus L., was found to strongly attract infective RKN juveniles and actively secrete chemoattractants into the liquid culture media. The chemo-attractant in the culture media supernatant was purified using hydrophobicity and anion exchange chromatography, and found to be enriched in carbohydrates.ResultsMonosaccharide analyses suggest the chemo-attractant contains a wide array of sugars, but is enriched in arabinose, galactose and galacturonic acid. This purified chemoattractant was shown to contain pectin, specifically anti-rhamnogalacturonan-I and anti-arabinogalactan protein epitopes but not anti-homogalacturonan epitopes. More importantly, the arabinose and galactose sidechain groups were found to be essential for RKN-attracting activities. This chemo-attractant appears to be specific to M. incognita, as it wasn’t effective in attracting other Meloidogyne species nor Caenorhabditis elegans.DiscussionThis is the first report to identify the nematode attractant purified from root exudate of L corniculatus L. Our findings re-enforce pectic carbohydrates as important chemicals mediating micro-organism chemotaxis in the soil, and also highlight the unexpected utilities of the SR culture system in root pathogen research.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fpls.2022.1008725/fullTest; https://doaj.org/toc/1664-462XTest

الوصول الحر: https://doaj.org/article/621f14c24e814d0dae58cb1cefbf765cTest

المؤلفون: Hayato Ishikawa, Jukiya Sakamoto, Mariko Kitajima

المصدر: Chemical and Pharmaceutical Bulletin. 2022, 70(9):662

المؤلفون: Takashi Ishida, Haruna Yoshimura, Masatsugu Takekawa, Takumi Higaki, Takashi Ideue, Masaki Hatano, Masayuki Igarashi, Tokio Tani, Shinichiro Sawa, Hayato Ishikawa

المصدر: Scientific Reports, Vol 11, Iss 1, Pp 1-13 (2021)

مصطلحات موضوعية: Medicine, Science

الوصف: Abstract The discovery and useful application of natural products can help improve human life. Chemicals that inhibit plant growth are broadly utilized as herbicides to control weeds. As various types of herbicides are required, the identification of compounds with novel modes of action is desirable. In the present study, we discovered a novel N-alkoxypyrrole compound, kumamonamide from Streptomyces werraensis MK493-CF1 and established a total synthesis procedure. Resulted in the bioactivity assays, we found that kumamonamic acid, a synthetic intermediate of kumamonamide, is a potential plant growth inhibitor. Further, we developed various derivatives of kumamonamic acid, including a kumamonamic acid nonyloxy derivative (KAND), which displayed high herbicidal activity without adverse effects on HeLa cell growth. We also detected that kumamonamic acid derivatives disturb plant microtubules; and additionally, that KAND affected actin filaments and induced cell death. These multifaceted effects differ from those of known microtubule inhibitors, suggesting a novel mode of action of kumamonamic acid, which represents an important lead for the development of new herbicides.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2045-2322Test

الوصول الحر: https://doaj.org/article/f04f248822be443f8ef9a467bc388a1fTest

المؤلفون: Hayato Ishikawa, 石川 勇人

المصدر: 有機合成化学協会誌 / Journal of Synthetic Organic Chemistry, Japan. 2022, 80(4):379

المؤلفون: Hayato Ishikawa, Jukiya Sakamoto, Kenta Rakumitsu, Lia Dewi Juliawaty, Mariko Kitajima, Nanako Nakashima

المصدر: Chemical and Pharmaceutical Bulletin. 2022, 70(2):187

المؤلفون: Akiko Okumura, Hayato Ishikawa, Hiromichi Fujino, Hiroya Yoshida, Junichiro Kitai, Keijo Fukushima, Koki Takahashi, Mariko Kitajima, Shuntaro Hayashi, Takaya Misao, Takuto Muraki, 三竿 顕也, 北井 淳一郎, 北島 満里子, 吉田 博也, 奥村 明子, 村木 拓斗, 林 隼太郎, 石川 勇人, 福島 圭穣, 藤野 裕道, 高橋 晃輝

المصدر: Proceedings for Annual Meeting of The Japanese Pharmacological Society. 2022, :4-320

المؤلفون: Mario A. Tan, Hayato Ishikawa, Seong Soo A. An

المصدر: Nutrients, Vol 14, Iss 19, p 3962 (2022)

مصطلحات موضوعية: Alzheimer’s disease, amyloid-beta, neuroprotection, nicotinamide, Pandanus amaryllifolius, Thioflavin T, Nutrition. Foods and food supply, TX341-641

الوصف: Accumulation of amyloid-beta (Aβ) plaques leading to oxidative stress, mitochondrial damage, and cell death is one of the most accepted pathological hallmarks of Alzheimer’s disease (AD). Pandanus amaryllifolius, commonly recognized as fragrant screw pine due to its characteristic smell, is widely distributed in Southeast Asia and is consumed as a food flavor. In search for potential anti-AD agents from terrestrial sources, P. amaryllifolius was explored for its in vitro anti-amyloidogenic and neuroprotective effects. Thioflavin T (ThT) assay and the high-throughput screening multimer detection system (MDS-HTS) assay were used to evaluate the extracts’ potential to inhibit Aβ aggregations and oligomerizations, respectively. The crude alcoholic extract (CAE, 50 μg/mL) and crude base extract (CBE, 50 μg/mL) obstructed the Aβ aggregation. Interestingly, results revealed that only CBE inhibited the Aβ nucleation at 100 μg/mL. Both CAE and CBE also restored the cell viability, reduced the level of reactive oxygen species, and reversed the mitochondrial dysfunctions at 10 and 20 μg/mL extract concentrations in Aβ-insulted SY-SY5Y cells. In addition, the unprecedented isolation of nicotinamide from P. amaryllifolius CBE is a remarkable discovery as one of its potential bioactive constituents against AD. Hence, our results provided new insights into the promising potential of P. amaryllifolius extracts against AD and further exploration of other prospective bioactive constituents.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2072-6643/14/19/3962Test; https://doaj.org/toc/2072-6643Test

الوصول الحر: https://doaj.org/article/70d7a2e5ebb14279a823185ffc886c3fTest

المؤلفون: Hayato Ishikawa, Shinya Shiomi, 塩見 慎也, 石川 勇人

المصدر: 有機合成化学協会誌 / Journal of Synthetic Organic Chemistry, Japan. 2021, 79(2):145

المؤلفون: Hayato Ishikawa, Morihiro Oota, Shinichiro Sawa, Syuuto Toyoda

المصدر: Plant Biotechnology. 2021, 38(1):157