Catalytic osmylation of cis and trans 2-cyclohexene-cyclohexanol (1a) and (1b) are carried out in the presence of N-methyl morpholine-N-oxide. Under the same conditions, only the cis isomer reacted, leading to triol (3). The steric hindrance of the equatorial OH group probably prevents the trans isomer from entering into such reaction. Triol (3) was also obtained from the reduction of the d...

Methyl tetra - 0-methyl- ?-D- glucopyranoside is stereoselectively prepared from tetramethyl-D- glucopyranose by using (MeI+NaH) in toluene (86%) or cyclohexane (85%), while its ?- isomer is best synthesized in hexamethyl phosphoramide (64%). Similarly, methyl tetra-o-methyl-?- D-mannopyranoside is synthesized in cyclohexane (80%), while its ?- isomer is predominantly prepared by (MeI+n-Bu...

the mössbauer spectra of nanoferrite materials such as ni0.25mn0.75fe2o4, co0.5mn0.5fe2o4 and ni0.4co0.6fe2o4 have been reported and the above materials were prepared by sol-gel combustion method using metal nitrates as source material and polyvinyl alcohol(pva) as agglomeration reducing agent. as the structural, thermal and magnetic properties (vsm) of the above ferrites have been published al...

i The Soret circular dichroism (CD) spectrum of carbonmonoxy myoglobin dtifers strikingly for the two heme isomers: Aqzl =+90 M-’cm-’ for isomer A, AQ21 = -7 M-’cm-’ for isomer B (Aojula et al., BiochemJ. 250, 853(1988)). This observation implies significant differences in the protein conformation andlor distortions of the heme from planarity between the two isomers. Molecular dynamics simulati...

Human haemoglobin was prepared containing [14C]haem in either the aor the fsubunits. Coupled oxidation of such hybrid haemoglobins with ascorbate and 02 showed that the biliverdin produced by the a-subunits contained approx. 55% aisomer and 45% f-isomer, whereas that produced by the fl-subunits contained approx. 75% a-isomer and 25% P-isomer. Coupled oxidation of isolated aand fl-subunits gave ...