I. Amino Acids A. Alkylamino Acids: :-Alkylamino acids, L-proline, L-valine. B. Hydroxyamino Acids: L-Serine, L-threonine, D-allothreonine, L-isoserine. C. Amino-amino Acids: L-2,3-Diaminopropionic acid, L-2,4-diaminobutyric acid. D. Carboxyamino Acids: L-Aspartic acid, 3-amino-pentanedioic acids. E. Thioamino Acids: D-Penicillamine, DOr L-methylcysteine, L-cysteine, L-methionine. F. Amido-amin...

Abstract Bicyclic lactams can be prepared from diethyl aminomalonate and substituted benzaldehydes by formation of a dimerised imidazolidine cycloadduct followed Dieckmann ring closure. The resulting N,N-heterocycles are metal-chelating but show no antibacterial activity.

Sodium 7beta-[(R)-2-(N(b)()-o-nitrobenzyloxycarbonyl)hydrazino-3-pheny lpropa namido]cephalosporanate (1) is described as a new type of beta-lactam antibiotic, which undergoes light-induced destruction of its beta-lactam moiety and hence becomes biologically inactive. This type of antibiotic holds the promise of self-destruction over a number of hours of exposure to light, so that it would not ...

The hydrolysis of two cephalosporins by three different beta-lactamases has been studied. Each enzyme caused a decrease in ultraviolet absorption, a loss of biological activity, and the release of the leaving group from the 3-position. The changes occurred at the same rate and to the same extent with each enzyme, and it is inferred that the loss of the leaving group is a consequence of, and not...

The two competing mechanisms in the reaction of 3-trialkylsilyloxy-2-aza-1,3 dienes to form beta-lactams through a [2+2] electrocyclic ring closure or tetrahydrooxazinan-4-ones via a [4+2] hetero-Diels-Alder reaction were studied using Density Functional computations. Although the [2+2] and [4+2] mechanisms are typical of dienes, their competition, starting from the same diene intermediate, has...

The global spread of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) since the mid-1990s is a major public health concern. The epidemiology of CA-MRSA differs from that of health-care-associated MRSA (HCA-MRSA), and this is reflected at the genetic level. Resistance to beta-lactams is encoded in the mecA gene, which is carried, along with resistance determinants for o...

The activity of MK-0826, a new carbapenem, against 309 Bacteroides fragilis group strains was investigated and compared with that of 11 other beta-lactam and 5 non-beta-lactam agents. MK-0826 showed excellent activity (MICs ranged from < or =0.06 to 4 microg/ml). The new carbapenem may be useful in the treatment of mixed anaerobic infections involving B. fragilis group strains.

Community-associated methicillin-resistant Staphylococcus aureus (MRSA) was first reported in Western Australia in the early 1990s from indigenous peoples living in remote areas. Although a statewide policy of screening all hospital patients and staff who have lived outside the state for MRSA has prevented the establishment of multidrug-resistant epidemic MRSA, the policy has not prevented SCCm...

[structure] A catalytic asymmetric reaction process was designed involving the use of solid-phase reagents and catalysts that constitute the packing of a series of "reaction columns". This process was applied to the catalytic asymmetric synthesis of beta-lactams, yielding pure product after crystallization with exceptional enantio- and diastereoselectivity.