Triphenylmethyl phosphonium

Using both a carbocyanine dye and another lipophilic cation, triphenylmethyl-phosphonium, Seligmann and Galhn found defective changes in the membrane potential in PMNs from patients with chronic granulomatous disease in response to FMLP or PMA, In PMNs from patients with other disorders of function the responses were normal. The resting membrane potential, the response to valinomycin, (an ionophore for potassium) and the response to the ionophore for Ca, were all normal or only slightly impaired. 

A suspension of mitochondria is incubated with pyruvate, malate, and l4C-labeled triphenylmethyl-phosphonium [TPP] chloride under aerobic conditions. The mitochondria are rapidly collected by centrifugation, and the amount of l4C that they contain is measured. In a separate experiment, the volume of the mitochondrial matrix space was determined so that the concentration of TPP cation in the matrix can be calculated. The internal concentration is found to be 1,000 times greater than that in the external solution. 

The retinoid-like compound bexarotene (63) is approved for treating skin lesions associated with T-cell lymphomas. The starting tetralin (60) is probably obtained by alkylation of toluene with dichloride (54). Fiiedel-Crafts acylation with the acid chloride (57), gives the ketone (61). This intermediate is then treated with the ylide from triphenylmethyl-phosphonium bromide. The carbonyl oxygen in the product (62) is now replaced by a methylene group. Saponfication of the ester affords the free acid and thus 63. °... 

Tellurate(II) Diodo-(2-naphthyl)-(triphenylmethyl-phosphonium) E12b. 297 (Ar2Te + I2)... 

The lipophilic phosphonium cations, TPP (tetraphenyl phosphonium) and TPMP" (triphenylmethyl phosphonium) can cross bilayer membranes as charged species and distribute according to the membrane potential [26]. Since they can be used at very low concentration they tend to disturb the potential less than the use of valinomycin. The gradients established can be estimated either iso topically, or by the use of an electrode specific to the cation [27]. The latter allows the membrane potential in mitochondrial incubations to be monitored continuously. However, a disadvantage of these cations, particularly in the case of TPP, is that they do not behave ideally but bind to components in the matrix. A number of techniques have been described for correcting the accumulation ratios of the cations [28,29]. 

Tricyclopropylphosphane, on treatment with an alkyl halide, undergoes alkylation resulting in formation of a phosphonium salt. The yields were good even when a bulky halide such as bromotriphenylmethane was used giving tricyclopropyl(triphenylmethyl)phosphonium bromide in 81% yield. ... 

Upon illumination a proton motive force is generated in whole cells, chromatophores and membrane vesicles. In membrane vesicles a proton motive force is generated which is inside alkaline and negative. The ApH, determined from the distribution of acetate, depends on the composition of the medium and is maximally 0.6 at an external pH of 7 the Aijj, measured from the distribution of triphenylmethyl phosphonium is about -70 mV. The proton motive force in membrane vesicles can thus reach values of around -110 mV (Michels, Konings, 1978). 

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