Conversion of N-acetyl-d-glucosamine to nitrogen-containing chemicals in high-temperature water

Available online 19 July 2019To demonstrate the conversion of renewable biomass to platform chemicals, we previously reported the non catalytic conversion of N-acetyl-D-glucosamine (GlcNAc), which is obtained from chitin, to nitrogen-containing chemicals; however, various aspects of this process were not clarified. Herein, we reported updated and expanded results for the synthesis of nitrogen-containing chemicals from GlcNAc in high-temperature water at 180-280 degrees C and 25 MPa with a reaction time of 5-34 s. The main products were 2-acetamido-2,3-dideoxy-D-erythro-hex-2-enofuranose (Chromogen I) and 3-acetamido-5-(1',2'-dihydroxyethyl)furan (Chromogen III) with the maximum yields of 37.0% and 34.5%, respectively. Although 3-acetamido-5-acetylfuran was expected to form by the dehydration of Chromogen III, a yield of only < 1% was obtained, likely because the dehydration of Chromogen III is difficult in the absence of a catalyst. The evaluation of the effects of acid and base catalysts on the dehydration of GlcNAc revealed that the acid catalyst suppressed the transformation of GlcNAc to Chromogen I and promoted the transformation of Chromogen I to Chromogen III, whereas the base catalyst had the opposite effects on these processes. The synthesis of nitrogen-containing chemicals from GlcNAc in high temperature water is an environmentally benign method for utilizing renewable chitin biomass.ArticleFUEL PROCESSING TECHNOLOGY. 195:106154 (2019)journal articl

Non-catalytic conversion of chitin into Chromogen I in high-temperature water

Epub 2019 June 21The non-catalytic conversion of chitin into N-acetyl-ᴅ-glucosamine (GlcNAc) derivatives such as 2-acetamido-2,3-dideoxy-ᴅ-erythro-hex-2-enofuranose (Chromogen I) was investigated in high-temperature water at 290–390 °C and 25 MPa with a reaction time of 0–180 min. High-temperature water treatment is a promising method for chitin conversion as it does not require the use of any additional organic solvents or ionic liquids. A semi-batch reactor was developed to control the reaction temperature and time. It was found that the chitin powder could be converted into a water-soluble fraction in ~90% yield, with Chromogen I being obtained in a maximum yield of 2.6%. Furthermore, a kinetic model was developed to estimate the reaction rate for the conversion of the chitin powder to the water-soluble fraction.ArticleINTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES. 136:994-999 (2019)journal articl

Non-catalytic dehydration of N,N'-diacetylchitobiose in high-temperature water

Accepted 28 Jul 2014Non-catalytic synthesis of 4-O-β-2-acetamido-2-deoxy-D-glucopyranosyl 2-acetamido-2,3-dideoxydidehydro-glucopyranose (GND) from chitin disaccharide, N,N′-diacetylchitobiose (GlcNAc)2, was achieved, with a maximum yield of 24.7% in high-temperature water at 120–220 °C and 25 MPa with a reaction time of 8–39 s.ArticleRSC ADVANCES. 4(64):33651-33657 (2014)journal articl

Effects of mismatch of internal tempo and external tempo on walking and emotions <Article>

A music tempo that does not correspond with a walking tempo results in an experience of difficulty in walking and generates unpleasant internal feelings. It has been posited that walking tempo is an internal tempo and that music tempo is an external one. We evaluated how participants felt when their internal tempo did not correspond with their external tempo. We also studied their internal tempo's influence on their walking. Twenty undergraduate students participated in the experiment. They walked on a treadmill and adjusted the speed so as to walk at the most comfortable speed. Participants' pleasure, relaxation, and anxiety while walking with or without sounds of metronome, the tempo of which was 50, 90, 140, or 180 beats per minute, were evaluated by MCL-S.2 scale. Results showed that participants felt more pleasant and relaxed when their internal and external tempos were in agreement. Conversely, participants felt more anxious when the tempos did not correspond. Walk tempo did not significantly vary with the external metronome tempo. Some factors which obscure the effects of external tempo are discussed

Clinical significance of PMI with GC patients

Aim : We investigated whether preoperative or postoperative inflammatory markers and psoas muscle index (PMI), and their change after surgery, could predict postoperative recurrence in gastric cancer (GC). Methods : Thirty-five patients who underwent curative gastrectomy for pStage II and III GC were retrospectively reviewed. The relationship between neutrophil–lymphocyte ratio (NLR), prognostic nutritional index (PNI), Glasgow Prognostic Score (GPS), and PMI, as well as postoperative recurrence, was analyzed presurgery and at 6 months after surgery. Results : In the preoperative data, there was a significant association between postoperative recurrence and high NLR, low total protein, low albumin, low PNI, and high GPS. In the data from 6 months after surgery, there was a significant association between postoperative recurrence and high NLR, high C-reactive protein, and high GPS. The reduction in PMI at 6 months after surgery relative to preoperative data was significantly greater in the cases with recurrence than in those without recurrence. No patients whose PMI increased compared with presurgery had recurrence. Conclusions : The postoperative reduction in PMI at 6 months after surgery relative to presurgery could be a predictive marker of recurrence after curative gastrectomy for patients with pStage II and III GC

Thermodynamic Analysis for Binding of 4-O-β-tri-N-acetylchitotriosyl Moranoline, a Transition State Analogue Inhibitor for Hen Egg White Lysozyme

4-O-β-tri-N-acetylchitotriosyl moranoline (GN3M) is a transition-state analogue for hen egg white lysozyme (HEWL) and identified as the most potent inhibitor till date. Isothermal titration calorimetry experiments provided the thermodynamic parameters for binding of GN3M to HEWL and revealed that the binding is driven by a favorable enthalpy change (ΔH° = −11.0 kcal/mol) with an entropic penalty (−TΔS° = 2.6 kcal/mol), resulting in a free energy change (ΔG°) of −8.4 kcal/mol [Ogata et al. (2013) 288, 6,072–6,082]. Dissection of the entropic term showed that a favorable solvation entropy change (−TΔSsolv° = −9.2 kcal/mol) is its sole contributor. The change in heat capacity (ΔCp°) for the binding of GN3M was determined to be −120.2 cal/K·mol. These results indicate that the bound water molecules play a crucial role in the tight interaction between GN3M and HEWL

Environmental DNA preserved in marine sediment for detecting jellyfish blooms after a tsunami

堆積物の環境DNAで探る過去の出来事 --津波直後のクラゲ大発生を検知--. 京都大学プレスリリース. 2021-08-23.Environmental DNA (eDNA) can be a powerful tool for detecting the distribution and abundance of target species. This study aimed to test the longevity of eDNA in marine sediment through a tank experiment and to use this information to reconstruct past faunal occurrence. In the tank experiment, juvenile jack mackerel (Trachurus japonicus) were kept in flow-through tanks with marine sediment for two weeks. Water and sediment samples from the tanks were collected after the removal of fish. In the field trial, sediment cores were collected in Moune Bay, northeast Japan, where unusual blooms of jellyfish (Aurelia sp.) occurred after a tsunami. The samples were analyzed by layers to detect the eDNA of jellyfish. The tank experiment revealed that after fish were removed, eDNA was not present in the water the next day, or subsequently, whereas eDNA was detectable in the sediment for 12 months. In the sediment core samples, jellyfish eDNA was detected at high concentrations above the layer with the highest content of polycyclic aromatic hydrocarbons, reflecting tsunami-induced oil spills. Thus, marine sediment eDNA preserves a record of target species for at least one year and can be used to reconstruct past faunal occurrence

Porcine Enamel Protein Fractions Contain Transforming Growth Factor‐β1

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141064/1/jper1688.pd