Two metabolites (1, and 2) ) of p-aminobenzoic acid (PABA) which act as cofactors for the hydroxylation of aniline by acid-fast bacteria are biosynthesized from Aj.
The 7 carbons of PABA are incorporated directly into metabolite 2 (( as shown with both ring-labeled and carboxy-labeled Af).
Thirty-five of the 36 carbon atoms arise from Aj.
All 28 carbons of metabolite 1 (( a product of mild acid hydrolysis of 2) arise from Aj.
Metabolite 1, isolated from the medium, however, showed a lower specific activity, which indicates endogenous synthesis of this metabolite.

Vigorous acid hydrolysis of metabolite 1, destroyed the biological activity of the compound and liberated two aryl amines.
Fragment A has been obtained in crystalline form as a dioxalate salt and free base.
Preliminary evidence tentatively indicates that the molecule (metabolite 1) ) is cleaved at a secondary amide bond.
(N. H. Sloane;
chemical studies are being pursued with the cooperation of K.G. Untch.
) studies on esterases

-- Research on esterases in mammalian sera was continued.
One of the most interesting findings was the extreme sensitivity of plasma arylesterases to rare earth ions.
The inhibition of the enzyme by very low concentrations of lanthanum ion is probably the strongest known biological effect of rare earth salts.
Various metal ions have been found to protect plasma arylesterase against inactivation by urea and guanidine.
The effects can be related to the structure of this enzyme.
The non-identity of serum and red blood cell arylesterase was also established.
Furthermore, the hydrolysis of paraoxon was studied in mammalian sera, and it was found that it is hydrolyzed by albumin (or a factor attached to it) in addition to arylesterase.
Selective inhibitors can distinguish the two activities.
Investigations on the acceleration of human plasma cholinesterase were carried further.
(E. G. Erdos, L. E. Boggs, C. D. Mackey) biophysical studies on modified fibrous proteins

-- Electron-microscopical and physical-chemical methods were used to demonstrate the renaturation of heat-denatured collagen and ribonucleic acid.
(R. V. Rice)

A method was devised for extracting and purifying soluble earthworm collagen (EWC).
It was observed that EWC macromolecules are the same diameter (15 a.) but much longer (up to several microns) than vertebrate tropocollagen.
This unusual collagen also was shown to undergo a reversible thermal phase transformation.
(R. V. Rice, M. D. Maser) studies on peptides and peptidases

-- This investigation involved several aspects.
Substance Z, an active urinary peptide, was purified by extraction in organic solvents and repeated column chromatography;
high-voltage electrophoresis and paper chromatography were used in preliminary structural studies;
pharmacological effects in vitro on isolated surviving organs and in vivo on blood pressure were assayed;
special equipment required for registering respiration and for recording the contraction of smooth muscles under various conditions was developed by the Instruments Section (Victor Jackman, W. C. Barnes, J. F. Reiss);
and enzymes which terminate the action of peptides such as bradykinin and perhaps Substance Z were studied.
Experiments are in progress to develop ultraviolet spectrophotometric techniques for assaying these enzymes and for studying their sensitivity to metal ions.
(E. G. Erdos, C. D. Mackey, A. G. Renfrew, W. B. Severs, E. M. Sloane) seed proteins

-- In a physiochemical study of seed proteins, the globulins of the Brazil nut have been investigated.
In addition to the known principal globulin, excelsin, three other ultracentrifugally distinct components have been observed.
A water-soluble protein of quite low molecular weight (ca. 10,000) has also been found in this system and partly characterized.
(E. F. Casassa, H. J. Notarius)

continuum mechanics and viscoelasticity

theory of non-newtonian fluids

-- On the basis of a differentiability assumption in function space, it is possible to prove that, for materials having the property that the stress is given by a functional of the history of the deformation gradients, the classical theory of infinitesimal viscoelasticity is valid when the deformation has been infinitesimal for all times in the past.
By strengthening the differentiability assumption, it has been possible to derive second and higher order theories of viscoelasticity.
In the second-order theory, one of the normal stress differences can be calculated from the first-order stress relaxation function.
(B. D. Coleman with Walter Noll, Department of Mathematics, Carnegie Institute of Technology) viscoelastic measurements

-- An extensive series of measurements was made on a high-density polyethylene in a torsion pendulum instrument using forced sinusoidal oscillation, free vibration, and creep measurements over the temperature range of Af to 80-degrees-C.
As many as seven decades of the time scale were thus covered isothermally.
The simple time-temperature equivalence valid for many amorphous systems did not hold here.
It was possible, however, to decompose the compliance into a sum of a frequency-independent component and two viscoelastic mechanisms, each compatible with the Boltzmann superposition principle and with a consistent set of time-temperature equivalence factors.
(Hershel Markovitz, D.J. Plazek, Haruo Nakayasu)

geochemistry

trace elements in tektites, meteorites, and related materials

-- The results of microanalysis of tektites (natural glasses of unknown origin) for gallium and germanium have shown that these glasses are probably produced from terrestrial (or less likely from lunar) matter by impact of a celestial body.
The gallium / germanium ratio is higher than that for ordinary igneous, metamorphic, or sedimentary matter as a result of selective volatilization of the components of the tektite.
Gallium oxide is less volatile than silica (the main constituent of tektites) and germanium oxide is more volatile.
Australites (tektites from Australia) give the appearance of a second melting.
In conformity with this conclusion a higher trace gallium content was found in the portion (flange) that has undergone a second melting.
The silicate fractions of stony meteorites show gallium / germanium ratios similar to those of tektites because they too have undergone melting at some point in their histories.

Libyan Desert silica-glass, another natural glass, is composed of nearly pure silica and has the same trace germanium content as sands in the area.
The gallium content, however, has been enhanced five-fold.
This glass is probably formed from Libyan Desert sands by comet or stony-meteorite impact.

Nickel-iron meteorites with sufficient kinetic energy to produce large terrestrial explosion craters may nevertheless melt only small quantities of material.
Most of the impact energy is spent in crushing and fragmentation.
When rapid quenching follows melting, impact glasses may result.
These always contain metallic inclusions.
Impact glasses not containing elemental nickel-iron may have been produced by stony meteorites or comets.
No meteorites have ever been recovered from paleoexplosion craters, and recent craters containing impact glass have all been produced by metallic meteorites with the exception of Aouelloul crater, Adrar, Western Sahara Desert.
This crater contains impact glass with no metallic inclusions and no meteoritic material has been recovered.
(A. J. Cohen, John Anania)

inorganic chemistry

Preparation of a coordination compound is often accomplished by the simple method of reacting a metal salt with a ligand in a suitable solvent such as an alcohol.
By applying this general principle, a great number of complex compounds of osmium, ruthenium, iridium, and rhenium, with triphenylphosphine, triphenylarsine, and triphenylstibine have been obtained in this laboratory during the past few years.
(Lauri Vaska, E. M. Sloane, J. W. DiLuzio) In the absence of direct evidence to the contrary, decomposition of solvent alcohol and coordination of its fragments to the metal were not considered, following the above heretofore-accepted assumption in preparative coordination chemistry.
Recent work with radiocarbon and deuterated alcohols as solvents, however, has given evidence that metal-hydrido and carbonyl complexes may be readily formed by reaction with alcohol in some of these systems.
Some of the previously reported compounds have thus been reformulated and a series of new hydrido and carbonyl compounds discovered, the more representative examples being Af, Af, Af, Af and Af (Af).

The coordination complexes formed by transition metals with primary and secondary phosphines and arsines are being investigated (R. G. Hayter).
Particular interest is directed towards the condensation of these ligands with metal halides to form substituted phosphide or arside complexes.
During the past year, these ligands have yielded some unusual five-coordinate complexes of nickel (2) and some interesting binuclear phosphorus-bridged complexes of palladium (2) (see figure), as well as new compounds of the well-known type Af.
The structures, properties, and reactions of these compounds are being studied.

In another study chromium-substituted aluminum oxyhydroxides and related species, prepared homogeneously by high-temperature hydrolysis, are being characterized and investigated spectrally in the ultraviolet region with a view to identification and semiquantitative estimation of the phases formed under varying preparative conditions.
(J. A. Laswick, N. L. Heatwole)

structure and properties of macromolecules

elasticity of macromolecular networks

-- The theory of elasticity of Gaussian networks has been developed on a more general basis and the equations of state relating variables of pressure, volume, temperature, stress and strain have been precisely formulated.
Simple elongation has been treated in detail.
The various stress-temperature coefficients for constancy of volume and strain, constancy of pressure and strain, and constancy of pressure and length have been interrelated.
The dilation accompanying elongation and the simultaneously developed anisotropy of compressibility have been related to the elongation.
In continuation of these theoretical studies, a more precise elucidation of the effects of imperfections in network structure is sought.
(P. J. Flory, C. A. J. Hoeve) chain conformations of polymeric chains

-- Recent theoretical work to calculate the dimensions of polymeric chains by Volkenstein and Lifson has been extended to include more general types of chains.
The mean-square end-to-end distance of the polyisobutylene chain has been calculated in reasonable agreement with values deduced from viscosity data.
These studies are being extended to different polymers to increase our knowledge about the hindrances to rotation around chain bonds.
(C. A. J. Hoeve, A. A. Blumberg) crystallization in polymers and copolymers

-- The crystallization of copolymers comprising Af units interspersed with a minor percentage of Af is limited by the inability of the crystal lattice characteristic of the former to accommodate the bulky side group of the latter.
Only uninterrupted sequences of the former are eligible for formation of crystallites.
Limitations on the lengths of these sequences diminish the stability of the comparatively short crystallites which can be formed, and this is reflected in a broadening of the melting range.
(Robert Chiang, J. B. Jackson, P. J. Flory) Carefully executed melting studies on this system (M. J. Richardson) permit quantitative estimation of the instability engendered by reduced crystallite length.
The complex morphology of polycrystalline homopolymers is necessarily dependent on the same factor.
Hence, the present studies offer a possible basis for interpretations in the latter field.
Contraction of muscle

-- Glycerinated muscle, in the presence of the physiological agent (ATP) responsible for delivering energy to the mechanochemically active proteins of muscle, has been shown to undergo a contraction which is highly sensitive both to temperature and to solvent composition in mixtures of alcohols and water.
Experiments carried out over long periods of time in order to allow establishment of a steady state have shown that the onset of contraction and its completion are confined to an interval of several degrees Centigrade and to a concentration range of only several per cent.
The contraction therefore partakes of the character of a phase transition.
While ATP appears to be necessary for the occurrence of contraction, its presence and enzymatic hydrolysis of it by the muscle protein myosin are not the only criteria for contraction.
(C. A. J. Hoeve, P. J. Flory) anionic Polymerization

-- One of the principal aims of anionic polymerization techniques is the synthesis of polymers of extremely narrow molecular weight distribution.
A simple process for the preparation of nearly monodisperse polystyrene of predictable molecular weight has been developed.
The preparation of such products is not new, but the systems heretofore employed in polymerizations have commanded considerable experimental skill and starting materials of a high purity.
In the new process impurities present in the solvent (benzene), the monomer, and in the reaction system which would cause deactivation of propagation centers, are rendered inactive prior to polymerization by gradual addition of initiator, a mixture of butyl-lithium and telomeric styryl-lithium, at a temperature low enough to suppress chain growth.
Upon completion of the purging step, additional initiator appropriate for the molecular weight of the sample desired is added, and the system is then warmed to the polymerization temperature, at which the reaction is allowed to go to completion.
The predictability of the molecular weights was found to be within 10% for the polymers prepared, with Af ratios less than 1.1.

Contrary to observations with ethers, no apparent change of the reactivity of the chain ends takes place over considerable periods of time in benzene as solvent.