Mixing functions, asymmetric

Artemisia ketone (94), derived from IPP and DMAPP in Santolina chamaecyparissus, is asymmetrically labeled that is, the label from IPP is incorporated at much greater levels than that from DMAPP (Allen et al., 1977). A dehydrogenase system rather than a mixed-function oxidase (MFO) system based on cytochrome P-450 appears to be involved in formation of artemisia ketone. 

Chemical properties of deposited monolayers have been studied in various ways. The degree of ionization of a substituted coumarin film deposited on quartz was determined as a function of the pH of a solution in contact with the film, from which comparison with Gouy-Chapman theory (see Section V-2) could be made [151]. Several studies have been made of the UV-induced polymerization of monolayers (as well as of multilayers) of diacetylene amphiphiles (see Refs. 168, 169). Excitation energy transfer has been observed in a mixed monolayer of donor and acceptor molecules in stearic acid [170]. Electrical properties have been of interest, particularly the possibility that a suitably asymmetric film might be a unidirectional conductor, that is, a rectifier (see Refs. 171, 172). Optical properties of interest include the ability to make planar optical waveguides of thick LB films [173, 174]. 

Figure 3 Creation of the longitudinal order by cross-correlation as a function of the mixing time fm which follows the inversion of a carbon-13 doublet (due to a./-coupling with a bonded proton). The read-pulse transforms the longitudinal polarization into an in-phase doublet and the longitudinal order into an antiphase doublet. The superposition of these two doublets leads to the observation of an asymmetric doublet.

The resulting data were then treated by use of standard XPS methods. An asymmetric background correction using the Shirley function (described in detail by Castle and Salvi 16)), was used for all spectra, and peaks were fit by using a mixed Gaussian-Lorenzian distribution. Quantitation was performed with the equation (A/Sj) + EA/S, where A, is the peak area and 5/ is the atomic sensitivity factor for the element i being determined 17). Atomic sensitivity factors are empirical constants determined on standards of the elements 18). This yields an atom percentage (atom %) for each element at the surface of the material. 

Our 02 equilibrium curves for the four cross-linked mixed-valency hybrid Hbs indicate that there are significant functional differences between (ot+CN0)A(a0)cXL and (ot0+CN)A(a0)cXL. The two asymmetrical hybrid Hbs with two cyanomet subunits show a low cooperativity and the 02 affinity of these two hybrids is much lower than that of the isolated a or 0 subunit of Hb A (Miura et al., 1987). The overall 02-binding property as measured by P50 is on the order of (a0)A(a0)cXL > (a+CN0)A(a0)cXL > (a0+CN)A(a0)cXL >... 

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