SOME NEW KEYS TO COSMETIC CHEMISTRY--]9$6 237 cm. 2 in the first 20 minutes after cleansing of the area with ether, and dwindled to 20 micrograms per cm. 2 in 20 minutes after repeated cleansing over a six-hour period. 54 Human sebum was reported to contain twelve aliphatic alcohols of 14 to 24 carbon atoms, straight and branched, saturated and unsaturated 5' in the free acid fraction 31 fatty acids of seven to 18 carbon atoms were detected and estimated by gas-liquid chromatography, •ø including some highly branched and some mono- and di-unsaturated acids. CELLS Improved methods for locating substances within cells and estimating their concentration include a method for determining dry weight within a cell body •7 which is more practical than the interference method and methods for determining four enzymes in single large cell bodies •8 the method for malic dehydrogenase requires only 10 -5 micrograms of dry material, or one two-thousandth the mass of a single cell body. A summary of factors identified as essential for growth of a mouse fibroblast in tissue culture lists 27 substances. 59 About 70 of the chemical elements are claimed to be plant nutrients in concentrations of 10 -• to 10 -•, and are postulated to constitute integral elements of the cell, indis- pensable in the chain of enzymic reactions. 60 A U.S. patent 6• was issued covering the use of metallic complexes as stimulants of cellular respiration, in cosmetics and topical pharmaceuticals. The action of colchicine in blocking mitosis was found to be inhibited by adrenocortical hormones, which favour mitosis. 6• A substance was isolated from deoxyribonucleic acid preparations which markedly promotes cell division in concentrations as low as 1 microgram per litre the promoter was named kinetin, and was shown to be 6-furfurylpurine. 63 Analogues with sidechains of similar size to oeurfuryl were also active, and showed marked regulatory effects on developmental processes in plants, and on growth in animal tissues. 64 The molecular basis of cell division in yeasts was concluded to be reshaping of the protein comprising the inner cell wall by reduction of the S-S linkages, and protein disulphide reductase was characterised as the "division enzyme. "65 Glutathione was reported to play a metabolic role in mitosis. 66 On the yeast cell, evidence indicated the presence of at least two species of sites for binding cations, tentatively identified as phosphoryl and carboxyl groups these are on the periphery of the cell, isolated from endogenous cations by a permeability barrier. 67 Inside the liver cell, quinacrine was seen to be bound by numerous cell constituents, chiefly in its micellar form. 68 It has been observed that in the mitochondria of house-fly muscle cells, there are enzymes which dephosphorylate the triphosphates not only of adenosine but also of guanosine, inosine, uridine, and cytidine, and there appeared to be a separate enzyme for each nucleotide calcium

238 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS appeared to inhibit these enzymes, and magnesium or manganese to activate them.69 Mutation was induced at 1,000 times the natural rate by addition of 5-bromouracil and sulphanilamide to virus culture media. 7ø Strong evidence has been presented that human cells do not contain 48 chromosomes, as so long believed, but 46. 7• PROTEIN BIOSYNTHESIS Protein synthesis was observed in isolated cell nuclei from calf thymus, the participation of deoxyribonucleic acid being essential, and the high energy requirements being supplied by intranuclear systems which generate energy-rich triphosphates. 72 A specific surface and available energy were found indispensable for formation and orientation of peptide chains, and high-pressure resynthesis of proteins in the presence of proteolytic enzymes disproved the need of different specific catalysts for each peptide bond. TM New models and hypotheses were offered to explain the transfer of specificity from the deoxyribonucleic acid of the gene, through the specific ribonucleic acid, to the enzymes being synthesised, •4,75 and additional statistical evidence was offered to support an earlier hypothesis that the 20 amino- acids found in proteins are disposed in the new protein molecule to match the 20 possible triplets of nucleotide residues which can be formed from four different nucleotides, disregarding order. TM A chemical manufacturer announced the opening of a pilot plant which will be capable of producing all the essential amino acids except threonine. 77 PROTEIN STRUCTURE The complete amino-acid sequence of alpha-corticotropin was estab- blished, 79 as was that of beta-corticotropin 7• the latter contains 39 amino acids in its chain, but a 24-unit portion of the chain retains the hormonal activity. A new model was proposed for feather keratin, with 64 amino-acid residues in the 190A unit of pitch, and ten helixes coaxially aggregated by lateral H-bonds. TM It was shown that a • primary valence bond in a protein may have more apparent stability than the corresponding bond in a low molecular weight compound becaase of support by neighbottring H-bonds, which may account for some observed differences in the behaviour of pro- teolytic enzymes toward native and denatured protein substrates. • A new method was devised for measuring distances between protein sidechains, based on the absorption spectra of their compounds with molecules contain- ing two groups separated by known distances and capable of binding the two protein sidechains.•2 Melanin, keratin, and collagen formed crystalline substances'under mild influences such as ultrasonic waves, hydrogen peroxide, or various diseased