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Pseudoindoxyl is a partial skeleton found in various natural products. Its light-absorption properties make it useful for the design of functional molecules. However, versatile synthesis methods have not yet been reported. In this report, we present a versatile synthetic method for pseudoindoxyls using the direct S 0 → T n transition under visible light irradiation. We also discuss the application of pseudoindoxyls as photocatalysts.

Characterizing genes that regulate cell growth and survival in model organisms is important for understanding higher organisms. Construction of strains harboring large deletions in the genome can provide insights into the genetic basis of cell growth compared with only studying wild-type strains. We have constructed a series of genome-reduced strains with deletions spanning approximately 38.9% of the E. coli chromosome. Strains were constructed by combining large deletions in chromosomal regions encoding nonessential gene groups. We also isolated strains Δ33b and Δ37c, whose growth was partially restored by adaptive laboratory evolution (ALE). Genome sequencing of nine strains, including those selected following ALE, identified the presence of several Single Nucleotide Variants (SNVs), insertions, deletions, and inversions. In addition to multiple SNVs, two insertions were identified in ALE strain Δ33b. The first was an insertion at the promoter region of pntA , which increased cognate gene expression. The second was an insertion sequence (IS) present in sibE , encoding the antitoxin in a toxin-antitoxin system, which decreased expression of sibE . 5 strains of Δ37c independently isolated following ALE harboring multiple SNVs and genetic rearrangements. Interestingly, a SNV was identified in the promoter region of hcaT in all five strains, which increased hcaT expression and, we predict, rescued the attenuated Δ37b growth. Experiments using defined deletion mutants suggested that hcaT encodes a 3-phenylpropionate transporter protein and is involved in survival during stationary phase under oxidative stress. This study is the first to document accumulation of mutations during construction of genome-reduced strains. Furthermore, isolation and analysis of strains derived from ALE in which the growth defect mediated by large chromosomal deletions was rescued identified novel genes involved in cell survival., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Kotaka, Hashimoto, Lee and Kato.)

It is a major and complex task to accelerate an ion which has the same charge to mass ratio with strong contaminant ions, such as 12 C 4+ in the 18 O 6+ beam. An innovative method has been developed to suppress the contaminant ions in the Electron Cyclotron Resonance (ECR) ion source by introducing Li vapor. The ion distribution inside the ECR zone was obtained by the optical analysis of ions inside the ECR ion source. The 12 C 4+ ions were suppressed as much as by a factor of 10, whereas the 18 O 6+ beam changed little with the use of this technique.