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A domino synthesis of 2,3-dialkylidenetetrahydrofurans based on Prins-type cyclization of 3,5-diynols and aldehydes is described. In the present reaction, skeletal reorganization of the Prins-cyclized intermediates proceeds via a ring-opening reaction followed by intramolecular (hemi)acetalization of the resulting 4-en-1-yn-3-ones. Furthermore, a representative product undergoes a Diels-Alder reaction with dimethyl acetylenedicarboxylate (DMAD) to afford a highly substituted 2,3-dihydrobenzofuran.

Cysteine residues are absolutely indispensable for the reactions of almost all enzymes involved in the dissimilatory oxidation pathways of reduced inorganic sulfur compounds. Tetrathionate hydrolase from the acidophilic iron- and sulfur-oxidizing bacterium Acidithiobacillus ferrooxidans (Af-Tth) catalyzes tetrathionate hydrolysis to generate elemental sulfur, thiosulfate, and sulfate. Af-Tth is a key enzyme in the dissimilatory sulfur oxidation pathway in this bacterium. Only one cysteine residue (Cys301) has been identified in the deduced amino acid sequence of the Af-Tth gene. In order to clarify the role of the sole cysteine residue, a site-specific mutant enzyme (C301A) was generated. No difference was observed in the retention volumes of the wild-type and mutant Af-Tth enzymes by gel-filtration column chromatography, and surprisingly the enzyme activities measured in the cysteine-deficient and wild-type enzymes were the same. These results suggest that the sole cysteine residue (Cys301) in Af-Tth is involved in neither the tetrathionate hydrolysis reaction nor the subunit assembly. Af-Tth may thus have a novel cysteine-independent reaction mechanism.

Aims/Introduction: We investigated the association between coexisting diabetes at the time of cancer diagnosis, and the overall survival and incidence of second primary cancer in patients with cancer and receiving drug therapy for diabetes. Materials and Methods: We used cancer registry and administrative data of patients diagnosed with cancer at designated cancer care hospitals in Osaka Prefecture between 2010 and 2015. The presence of diabetes was identified from the prescription records of antidiabetic drugs in Diagnosis Procedure Combination System data. After adjusting for patient characteristics, we compared overall survival between patients with cancer with coexisting diabetes and those without coexisting diabetes using the Cox proportional hazards model. In addition, the impact of coexisting diabetes on the risk of developing second primary cancer was evaluated using a competing risk analysis. Results: Of the 131,701 patients with cancer included in the analysis, 6,135 (4.7%) had coexisting diabetes. The 5-year survival rates for patients with and without coexisting diabetes were 56.2% (95% confidence interval 54.8-57.6) and 72.7% (95% confidence interval 72.4-73.0), respectively. Coexisting diabetes was associated with a higher risk of developing second primary cancer (subdistribution hazard ratio 1.23; 95% confidence interval 1.08-1.41). In site-specific analysis, coexisting diabetes was associated with an increased risk for the development of second primary cancer of multiple myeloma, and cancer of the uterus, pancreas and liver. Conclusions: Coexisting diabetes was associated with a higher mortality and risk of developing second primary cancer in Japanese patients with cancer and on drug therapy for diabetes.

Amylose content is an important determinant of rice quality. Accurate non-destructive determination of amylose content remains a primary challenge for the rice industry. Here, we analysed the accuracy of three models for the non-destructive determination of amylose content. The models were developed by combining near-infrared spectra, colour, and physicochemical information relative to 832 brown rice samples from ten varieties produced between 2009 and 2017 in various regions of Hokkaido, Japan. Models describing low and ordinary amylose varieties were developed individually, merged, and validated using production year samples (2016-2017) different from the calibration set (2009)(2010)(2011)(2012)(2013)(2014)(2015). The resulting accuracy was suitable for industrial application. With standard error of prediction = 0.70% and ratio of performance deviation = 3.56, the combination of near-infrared spectra and physicochemical information produced the most robust model, enabling more precise rice quality screening at grain elevators.