0.0007 at pH 7.2: 0.0017 at pH 7.6 unitless
||Spinach Spinacia oleracea
||Heineke D, Riens B, Grosse H, Hoferichter P, Peter U, Flügge UI, Heldt HW. Redox Transfer across the Inner Chloroplast Envelope Membrane. Plant Physiol. 1991 Apr95(4):1131-1137 p.1134 left column bottom paragraphPubMed ID16668101
||"Spinach plants were grown in a climatized chamber with a 9 h
light/15 h dark cycle and leaves were stopped in liquid N2 after 8.5 h
light or 2 h dark."
||"From the data of Table IV - link and assuming a pH of 7.2, the cytosolic NADH to NAD ratio in the light is calculated as 0.5×10^-3 which in the presence of 0.6 mM NAD corresponds to an NADH concentration of 0.3 µM. At an assumed cytosolic pH of 7.6, a NADH to NAD ratio of 1.1×10^-3 and a NADH concentration of 0.7 µM is evaluated. For leaves kept in darkness very similar values are found, the NADH to NAD ratio amounting to 0.7×10^-3 (pH 7.2) and 1.7×10^-3 (pH 7.6) corresponding to a NADH concentration of 0.5 and 1.2 µM, respectively."