SECTIONAL TRANSACTIONS.—B. 465 
by Th. Wagner-Jauregg in crystalline condition. ‘The elementary analysis 
suggests the formula C,,;HN,O,. According to the experiments of 
P. Gyérgy, lactoflavine, three times recrystallised (m.p. 267°), promotes 
normal growth, when administered in doses of 5 y daily to rats deprived of 
vitamin Bg. 
The properties of flavines (lyochromes) and of carotenes (lipochromes) are 
in many respects complementary. 
Lyochromes. Lipochromes. 
Solubility Soluble in water Insoluble in water 
Colour Yellow, orange Yellow, orange, red 
Fluorescence Green (very strong) Yellow-green (weak) 
Combined with Proteins, polysaccharides — 
Composition Containing nitrogen Nitrogen-free 
Acids Resistant Labile 
Alkalies Labile Resistant 
Oxidation Resistant Labile 
Biologically related to Vitamin B, and enzymes Vitamin A 
5 Y & or yY-carotene 
Effective daily dose 5 y lactoflavine 2°5 7 B-carotene 
The flavines can be reversibly reduced (flavine + 2H= leuco-flavine), and 
therefore they act in the cell as transporters of oxygen. When combined 
with carriers of high molecular weight, they appear to act more strongly 
as enzymes (O. Warburg). Apparently the flavines are exogenous precursors 
of such oxidation-enzymes (pro-enzymes). The undialysable enzyme- 
preparations act also as vitamin B,; the dialysable flavines have no more 
enzymatic activity; the irradiated flavines, soluble in chloroform, have 
neither the properties of enzymes nor those of the vitamin. 
Flavines. Activity as 
Vitamin Bg. Enzyme. 
(1) Combined with carriers of high 
molecular weight (undialysable) + a 
(2) Crystallised dyestuffs (dialysable, 
insoluble in chloroform) . + = 
(3) Crystallised irradiated flavine 
(soluble in chloroform) . : - - 
Dr. R. P. Linsteap.—The phthalocyanines : a new class of synthetic 
colours. 
When phthalimide is heated wth certain metals, notably iron and 
magnesium, in a current of ammonia, a complex reaction occurs with the 
formation of highly coloured substances of a novel type. These have been 
named phthalocyanines from their origin and deep-blue colour. 
Identical compounds may be made from o-cyanobenzamide C,H,4(CN) 
CONH, by the action of metals and metallic derivatives, such as oxides, 
at temperatures of about 250° C. The metal may be eliminated from the 
magnesium compound by the action of concentrated sulphuric acid to yield 
phthalocyanine, the parent substance of the group. 
Like indigo and indanthrone, these substances may be purified by crystal- 
lisation from boiling quinoline and by sublimation in a vacuum, and may 
Beer snes as homogeneous macrocrystalline blue solids with a fine purple 
reflex 
Analysis shows them to contain the unit (CsH,N,) combined in their 
R2 
