Soya bean phosphatide

In the above table the substance marked with asterisk — an alcohol insoluble fraction of the total soya bean phosphatides — has been included. 

Fig. 4. Reversal of charge of alcohol soluble soya bean phosphatide with hexol nitrate or with La(N03)3, both as a function of the sol concentration.

On closer inspection of Table 2 on page 270, we see that the correlation between reciprocal hexol number and flocculability is not a rigorous one, so, for instance, Na agar though of lower reciprocal hexol number than the preceding Soya bean phosphatide, shows only opalescence with 6—1. 5—1 and 4—1. 

On the upper curve are situated egg lecithin, both soya bean phosphatides thymus and yeast nucleates all having ester phosphate groups. They may be called phosphate colloids. 

In Fig. 13 similar cation spectra of three other phosphate colloids (two different fractions of soya bean phosphatides and sodium nucleate) are given. 

A of alcohol soluble soya bean phosphatide, sensitised with triolein. 

B of alcohol insoluble soya bean phosphatide measured directly on the floccules, except for Li, Na and K where the measurements were carried out on suspended SiOa particles. 

Fig. 17. Reversal of charge spectra of Na pectate (carboxyl colloid) and of egg lecithin and alcohol soluble soya bean phosphatide (phosphate colloids) with alkali chlorides (and NH4CI).

All facts point to the phosphate group being more polarisable than water. We should thus expect the sequence Mg < Ca < Sr < Ba. Nearest to this comes the sequence found in egg lecithin and soya bean phosphatide (soluble in alcohol) Ca[Pg.294]

The sequence of the organic cations is from left to right quinine — strychnine — procaine — guadinine, except with alcohol soluble soya bean phosphatide where the reversal of charge points of procaine and guanidine are interchanged (the -4 -5 -2... 

So H. G. Bungenberg de Jong and C. van der Meer, Proc. Koninkl Nederland, Akad. Weten-schap., Amsterdaniy 45 (1942), 593 found for a soya bean phosphatide (soluble in alcohol) the following sequence of from left to right increasing reversal of charge concentrations ... 

For this investigation a sulphate colloid (Na agar), a carboxyl colloid (Na pectinate) and three phosphate colloids (Na yeast nucleate, purified egg lecithin, and a soya bean phosphatide fraction soluble in alcohol) were used. 

The sequence of the curves is however quite the same as in colloids in which all or a larger number of reversal of charge points could actually be reached. The ion spectra of the latter colloids, viz, egg lecithin and soya bean phosphatide (phosphate colloids) and Na pectinate (carboxyl colloid) are given in Fig. 26, 27 and 28. 

Fig. 27. Reversal of charge spectrum of alcohol soluble soya bean phosphatide (R.H.N = 3800) with substituted ammonium cations.

In Fig. 32 a (upper curve) the results are given for a soya bean phosphatide fraction (alcohol-soluble) h In this figure the reversal of charge concentration for each of the two salts separately is taken as 100% (CaCL = 0.045 N NaCl = 2.8 N).. We see that in this case at a definite NaCl concentration the CaCL concentration needed for reaching the reversal of charge point is more than twice as high (224%) as in the blank. 

Fig. 32. Reversal of charge of alcohol soluble soya bean phosphatide with mixtures of LiCl + NaCl, CaCla + NaCl and Co(NH3)fl CI3 + NaCl. Ordinates concentrations of Co(NH3)oCl3 or CaCl, or LiCl in the salt mixture expressed in % of the reversal of charge concentrations of these salts in the absence of NaCl.

Fig. 33. Reversal of charge of alcohol insoluble soya bean phosphatide, with mixtures of CaCla ]-MgCl, or La(NOs)3 4- Co(NH3)eCl3.

In Fig. 34 the results with a soya bean phosphatide fraction (the same kind as in 5 a) are given for a number of salt combinations, which comprise the already enumerated ones in 5a and further the combinations hexol nitrate + NaNOg UOo(NOg)3 + NaNOg Th(NO,), + NaNOg and La(NOg)g + NaNOg. ... 

Fig. 34, Relation between the maximum deviation from additive behaviour in the reversal of charge in salt mixtures (chlorides or nitrates of the stated ion -j- INaCl or NaNOg) and the quotient of the reversal of charge concentrations (alcohol soluble soya bean phosphatide).

Fig. 39. Reversal of charge of alcohol soluble soya bean phosphatide with mixtures of quinine hydrochloride -4 NaCl strychnine hydrochloride + NaCl and procaine hydrochloride + NaCl. The deviations from additive behaviour increase as Q rises. In this case the rule still holds that antagonism (i.e., elevation of the curve above the level of 100%) occurs when Q exceeds the numerical value of approximately 10.

Fig. 49. Electrophoretic velocity of Ti02 particles, suspended in 0.136% soya bean phosphatide sol (A), in 0.085% Na nucleate soi(F) or in mixtures of these sols (B, C, D, E), as a function of the CaClg concentration.

Fig. 16. Continuous valenqr rule and double valenqr rule in the action of salts on a positively charged complex coacervate (gelatin -f soya bean phosphatide).

The soya bean phosphatide insoluble in alcohol has a very low I. E. P. and also a very low colloid equivalent weight, with which is connected the fact that even in aqueous medium (without addition of auxiliary substances, see note 3, p. 405) complex flocculation occurs with 3 and 2-valent cations. According to the N P ratio = 2 1 one can here expect a considerable admixture of phosphatidic acid. 

The isoelectric gelatin is present as an amphoion and obviously the egg lecithin here also plays its part as an amphoion. In agreement with this is also the fact that one can in fact obtain similar flocculations with soya bean phosphatide, but these are less intense and the reversibility of the flocculation by added neutral salts leaves something to be desired. 

We already discussed previously (see p. 270, Table 2 p. 274 and 295) that egg lecithin, acting as a negative association colloid, has a very high equivalent weight, the soya bean phosphatide a much lower one. That means that the egg lecithin is much less mixed with acid constituents (for example phosphatidic acid) than the soya bean phosphatide and thus approximates much better to the theoretically pure phosphatide, which must consist exclusively of amphoions. 

Fig. 53. Comparison of some cations as regards the tricomplex flocculation of a mixture of of soya bean phosphatide sol and carrageen sol.

Fig. 58. Influence of a number of constant NaCl concentrations on the tricomplex flocculation of soya bean phosphatide + carrageen -f CaClg.

Fig. 45. Examples of triple coacervate drops in phosphatides (78 x lin.). a in a soya bean phosphatide sol containing CaClg to which 0.4 cc of aniline were added per 10 cc. b in an egg lecithin sol containing CaCb in which 30% triolein and 30% oleic acid calculated on the egg lecithin are present. The triple coacervate drops are thoroughly liquid because 3.6 mol per 1 ethyl alcohol was present in the medium.

---