Derivatives of p-aminobenzoic acid and their action on the growth of bacteria
SummaryVarious derivatives of P.A.B. obtained by introduction of substituents in the benzene-nucleus have been examined for their action on the growth ofAerobacter aerogenes in a simple synthetic medium and ofDiplococcus pneumoniae in ascites-broth without peptone.The following results have been obtained:1.The 2-amino, 3-amino, 3-chloro, 3-bromo, 2-methyl, 3-methyl, and 2.3-dimethyl derivatives of P.A.B., and also 2-sulfanilamido-4-aminobenzoic acid have sulfonamide activity.2.The 2-hydroxy, 2-fluoro, and 2-nitro derivatives have an antisulfonamide activity similar to the activity of P.A.B., although weaker.3.The 3-hydroxy, 2-chloro, and 2-bromo derivatives show sulfonamide-activity in relatively high concentrations. In lower concentrations they act as anti-sulfonamides.4.The 3-nitro, 2.6-dimethyl, and 3.5-dimethyl derivatives, and methyl 2-acetamino-4-amino-benzoate are completely inactive. These results have been compared with those of other investigators and the causes of some contradictions have been elucidated.
Isolation and Identification of Secondary Metabolites From Streptomyces sp. SP301
Seven compounds, namely aminobenzoates A to D (1-4), naphthalenecarboxylates A and B (5-6), and glycosylatelactone A (7), were isolated from the fermentation medium of Streptomyces sp. SP301. Of these, aminobenzoates C and D (3-4), naphthalenecarboxylate B (6), and glycosylatelactone A (7) are new compounds. Aminobenzoates A to D (1-4) shared a common aromatic starter unit, para-aminobenzoic acid , and biosynthesis involving a different pathway. The structures were elucidated on the basis of 1D- and 2D-Nuclear Magnetic Resonance (NMR) spectroscopy and HR-ESIMS analysis.
Solidarity. Reflections on an Emerging Concept in Bioethics. Summary
1. References to solidarity are currently on the increase in public discourse. In the UK and beyond, during economic crises and in a political climate where many feel that mutual assistance has lost currency, calls for a new and forceful emphasis on the meaning of solidarity are increasingly heard. Such appeals to solidarity are inevitably linked to ideas about how societies function, and about how and where the boundary between individual, familial, communal and societal spheres of responsibilities should be drawn.