Subgroups of powerful groups

We consider subgroups of powerfulp-groups. In particular, we give a new proof that allp-groups are sections of powerfulp-groups, give necessary and sufficient conditions for a 2-generator group to be a normal subgroup of a powerfulp-groups, and show thatp-groups of class 2, orp-groups with a cyclic commutator subgroup, are such normal subgroups.     

Inhibition of Diamino Pelargonic Acid Aminotransferase,an Enzyme of the Biotin Biosynthetic Pathway,by Amiclenomycin: A Mechanistic Study

The mechanism of action of amiclenomycin ( 1a ), a naturally occuring inhibitor of diaminopelargonic acid aminotransferase, has been established. The enzyme catalyzes the formation of an aromatic adduct between the inhibitor and pyridoxal‐5′‐phosphate. The structure of the adduct, determined by mass spectrometry, is in agreement with the reported X‐ray crystal structure. Kinetic parameters, characteristic of k_cat inhibitors, have been observed, with a K_I value of 2 μM and a k_inact value of 0.4 min^?1. The irreversibility of the inactivation observed, in spite of the absence of covalent bond between the inhibitor and the protein, reveals the high affinity of the adduct for the active site. Two other cis‐1‐amino‐4‐substituted‐cyclohexa‐2,5‐dienes, 3a and 4a , were also found to efficiently inhibit the enzyme. The trans‐isomers were either much less potent ( 1b ) or inactive ( 3b and 4b ). The aminocyclohexadiene moiety, which is, apparently, responsible for the inhibition, could constitute an original pharmacophore for the design of new herbicides.     

The simplest black holes

A relativistic gravitational theory in (1 + 1) dimensions is presented which exhibits many of the qualitative features of (3 + 1)-dimensional general relativity. The field equations are simple enough for undergraduates to solve yet rich enough in structure to form a useful pedagogical example for exploring the qualitative features of relativistic gravitation. Black hole solutions to the field equations of the theory are derived and its relationship to Newtonian gravity is discussed in detail.     

Realization of the transformation operator in the Jansen—Byers brown perturbation theory for exchange interactions

We obtain the general form and exhibit simple expressions for the transformation operator in the Jansen—Byers Brown exchange perturbation theory, without the use of an orthonormalization process.     

Biosynthesis of tuberin and xanthocillin from tyrosine

(2S)-Tyrosine (5) is incorporated stereospecifically into tuberin (1) with retention of the 3-$\text{pro}$-S proton and incomplete retention of the 2-S proton; a parallel pathway to the xanthocillin (4) is apparent with stereospecific retention of the 3-$\text{pro}$-R proton of tyrosine; results of experiments with $\text{threo}$- and $\text{erythro}$-3-hydroxytyrosine in relation to tuberin biosynthesis are reported.     

The synthesis of cyclopropyl analogues of precocene I

A new, short synthesis of precocene I is described together with the syntheses of two cyclopropyl analogues. One of these compounds showed interesting biological activity against the bean aphid, $\text{Aphis fabae}$     

Experimental study of 19Ne decay and its significance to the study of neutral weak currents

An upper limit of 0.003% for the beta decay of ¹⁹Ne to the 1.55 MeV level in ¹⁹F has been determined. Its significance for a recently suggested experiment to study neutral weak currents is discussed.     

Injectors and normal subgroups of finite groups

A class of subgroups,N-injectors, previously defined only for soluble groups, is here defined for some non-soluble groups. It is proved that injectors have some properties which resemble those of Sylow subgroups.