The BBL Crystal system (Becton Dickinson Microbiology Systems, Cockeysville, Md.) is a miniaturized bacterial identification method employing modified conventional and chromogenic substrates. Two products are currently available, the Rapid Stool/Enteric ID Kit and the Enteric/Nonfermenter ID Kit, each comprising thirty tests. We report an evaluation of both systems (using database version 1.1 for both) in the identification of 51 gram-negative taxa likely to be encountered commonly in the clinical laboratory. In all, 266 strains were tested in the Enteric/Nonfermenter ID Kit, and these represented 36 taxa of the family Enterobacteriaceae (188 strains), 5 oxidase-positive fermentative taxa (26 strains), and 10 nonfermentative taxa (52 strains). The majority of these same strains (203 of 266) were also tested in the Rapid Stool/Enteric ID Kit. The Enteric/Nonfermenter ID Kit performed as follows: Enterobacteriaceae, 93% correct, 6% not identified, and 1% incorrect; oxidase-positive fermenters, 88, 12, and 0%, respectively; and nonfermenters, 100% correct, although several only to the genus or group level. The Rapid Stool/Enteric ID Kit gave the following results: Enterobacteriaceae, 91% correct, 7% not identified, and 2% incorrect; oxidase-positive fermenters, 80, 13, and 7%, respectively (but results were based on only 15 strains); and nonfermenters, 100% correct (but results were based on only 11 strains). We found the systems extremely easy and rapid to use, and for the Enteric/ Nonfermenter ID Kit an identification rate of 100% in 40 of 51 taxa was achieved, with corresponding figures of 29 of 39 taxa for the Rapid Stool/Enteric ID Kit.

No abstract

Keywords: benzopyrones, halo ketones, chromeno [3,4-b]pyrrol-4(3H)-ones, cytotoxic agents.Benzo-α-pyrones (2H-chromen-2-ones), commonly known as coumarins are reported to possess a wide range of biological activities [1][2][3][4]. Many natural and synthetic coumarins are reported to be cytotoxic agents [5]. Coumarins react with DNA by means of intercalation between two base pairs of DNA. There they form cross linkage between two chains of DNA molecule, which is responsible for the carcinogenic and mutagenic effects. 3,4-Substituted coumarins have been reported to inhibit the proliferation of a number of human malignant cell lines in vitro [6-7] and to possess anticoagulant and antithrombotic activities. These properties and our long and continued interest in coumarin chemistry [8-10] encouraged us to synthesize new coumarin derivatives annelated at positions 3 and 4 by the pyrrole ring. Literature survey reveals various methods for synthesis of such fivemembered heterocycle using metal-catalyzed reactions [11], which involves use of very costly palladium metal. We report herein a very simple and novel method of synthesis of 3,4-annelated pyrrole derivatives of benzopyrones. To the best of our knowledge, this method has not been used for the synthesis of the pyrrole moiety.3-Acetamidocoumarin (1) was condensed with different aldehydes in the presence of a base to get the corresponding chalcones, but, instead, unreacted starting material was recovered. Therefore, acid hydrolysis of the compound 1 was carried out to obtain 3-amino-2H-chromen-2-one (2a) (Scheme 1) [12]. It was then condensed with cinnamoyl chloride in the presence of pyridine to produce the corresponding amide 3a.Similarly, compound 2a was condensed with different derivatives of cinnamoyl chloride in pyridine to give the corresponding 3-(3-arylacryloylamino)chromen-2-ones 3b-d. The structures of all these compounds were confirmed by their IR and NMR spectra (Scheme 1).

Bromination of 1-methylbenzo[f]chromen-3-one with N-bromosuccinimide gives 2-bromo-1-methylbenzo[f]chromen-3-one which, on condensation with different primary aromatic amines, gives tetracyclic aza-naphthalen-9-ones. Condensation of 2-bromo-1-methylbenzo[f]chromen-3-one with different secondary cyclic amines also gives tetracyclic oxa-naphthalen-9-one. The formation of 8-aza-naphthalen-9-one and 7,8-dioxa-naphthalen-9-one is confirmed by their single crystal analyses.

Condensation of 2‐bromo‐1‐methylbenzochromenone (II) with cyclic secondary amines or primary aromatic amines affords dioxapentalenonaphthalenone (III) and azanaphthalenones (V), respectively.