Free-bases and a nickel(II) complex of phenothiazine-bridged cyclic porphyrin dimers bearing self-assembling 4-pyridyl groups (M2-Ptz-CPDPy(OCn); M = H2 or Ni, OCn = OC6 or OC3) at opposite meso-positions have been prepared as host molecules for fullerenes. The free-base dimer (H4-Ptz-CPDPy(OC6)) includes fullerenes with remarkably high association constants such as 3.9 ± 0.
View Article and Find Full Text PDFChem Pharm Bull (Tokyo)
March 2003
Novel 9alpha and 9beta-hydroxy grayanotoxin II derivatives were prepared by photo-sensitized oxygenation of iso-grayanotoxin II and oxidation of grayanotoxin II tetraacetate with selenium dioxide respectively. The lethal dosage of 9alpha and 9beta-hydroxy grayanotoxin II were lower than that of grayanotoxin II. In addition, the lethal dosage of 9beta-hydroxy-dihydro grayanotoxin II was higher than that of dihydro grayanotoxin II.
View Article and Find Full Text PDF