Publications by authors named "Toshiya Komatsu"

Jadomycins, which are benzo[b]phenanthridine-type alkaloids isolated from Streptomyces venezuelae ISP5230, exhibit cytotoxic activity against multidrug-resistant breast cancer cells. We have previously achieved the total synthesis of jadomycins using the direct arylation of juglone as a key step. In this study, we achieved the total synthesis of jadomycin T and jadomycin aglycons using L-threonine and 1-amino-2-propanol as nitrogen sources.

View Article and Find Full Text PDF

We report a Pd-catalyzed β-arylation of cyclic α,β-unsaturated O-methyl oximes with aryl iodides. This reaction shows complete regioselectivity and excellent functional group tolerance. β-Arylation of 2-cyclohexen-1-one O-methyl oxime (existing as 2 : 1 E/Z mixture) with certain aryl iodides such as 4-iodoanisole affords only β-arylated (E)-O-methyl oximes.

View Article and Find Full Text PDF
Article Synopsis
  • Aldose reductase (AR) is linked to diabetic complications, prompting the study of Botryllazine A and its analogues for AR inhibition.
  • Analogues with aromatic bicyclic structures at the C5 position of the pyrazine ring showed better AR inhibitory effects than the original Botryllazine A.
  • Having benzoyl groups at C2 and C3 of the pyrazine ring wasn't necessary for high inhibitory activity, but phenolic hydroxyl groups at these positions were crucial for achieving effectiveness similar to the powerful AR inhibitor sorbinil.
View Article and Find Full Text PDF

A number of (Z)-4-arylmethylene-1H-imidazol-5(4H)-ones, which are related to the fluorescent chromophore of the Aequorea green fluorescent protein (GFP), have been synthesized and evaluated their in vitro inhibitory activity against recombinant human aldose reductase for the first time. The GFP chromophore model 1a, with a p-hydroxy group on the 4-benzylidene and a carboxymethyl group on the N1 position, exhibited strong bioactivity with an IC value of 0.36 μM.

View Article and Find Full Text PDF

We studied the interaction of LPS with albumin, hemoglobin or high-density lipoprotein (HDL), and whether the interaction affected the activity of LPS on neutrophils. These proteins disaggregated LPS, depending upon temperature and LPS:protein ratio. Albumin-treated LPS was absorbed by immobilized anti-albumin antibody and was eluted with Triton X-100, indicating that LPS formed a hydrophobic complex with albumin.

View Article and Find Full Text PDF

Groundwater replenishment by infiltration of road runoff is expected to be a promising option for ensuring a sustainable urban water cycle. In this study, we performed a soil infiltration column test using artificial road runoff equivalent to approximately 11-12 years of rainfall to evaluate the removal of pollutants by using various chemical analyses and bioassay tests. These results indicated that soil infiltration treatment works effectively to remove most of the pollutants such as organic matter (chemical oxygen demand (CODMn) and dissolved organic carbon (DOC)), P species, polycyclic aromatic hydrocarbons (PAHs), numerous heavy metals and oestrogenic activities.

View Article and Find Full Text PDF