Various extracts prepared from the traditional dye and medicinal plant Isatis tinctoria L. were submitted to a broad in vitro screening against 16 anti-inflammatory targets. Dichloromethane (DCM) extracts from dried leaves showed a marked cyclooxygenase (COX) inhibitory activity with a preferential effect on COX-2 catalysed prostaglandin synthesis. A supercritical fluid extraction (SFE) procedure employing CO2-modifier mixtures was developed by which the bioactivity profile and chromatographic fingerprint of the DCM extract could be reproduced. High-resolution activity directed on-line identification of the COX-2 inhibitory principle, using a combination of LC-DAD-MS with a microtitre-based bioassay, led to the identification of tryptanthrin (1) as the constituent responsible for essentially all COX-2 inhibitory activity in the crude extract. Following on-line identification, 1 was isolated at preparative scale and its structure confirmed by comparison with synthetic tryptanthrin. In an assay with lipopolysaccharide stimulated Mono Mac 6 cells, tryptanthrin (1) was of comparable potency (IC50 = 64 nM) than the preferential COX-2 inhibitors nimesulide (IC50 = 39 nM) and NS 398 (IC50 = 2 nM). The SFE extract and 1 showed no cytotoxicity in Mono Mac 6 and RAW 264.7 cells when tested at 100 microg/ml and 10 microM, respectively.

A convenient procedure for the regioselective preparation of polycyclic angular thiazolo[3,2-a]pyrimidin-5-ones is reported. 2-(Alkenylthio)quinazolin-4(3H)-ones and analogues thieno[2,3-d]pyrimidines were treated with bromine in acetic acid to obtain 1-(bromomethyl)-5H-thiazolo[3,2-a]quinazolin-5-ones 8a,d, and 1-(bromomethyl)-5H-thieno[3,2-e]thiazolo[3,2-a]pyrimidin-5-ones 8b,c,e,f, respectively. A route starting from 2-(alkenylamino)benzamides, which were converted to corresponding 2-thioxoquinazolin-4-ones and subsequently treated with bromine in acetic acid furnished angular 2-(bromomethyl)thiazolo[3,2-a]quinazolin-5-ones 11, or 3-(bromomethyl)[1,3]thiazino[3,2-a]quinazolin-6-one 14, respectively.

No abstract

RegioselectivePreparation of 3,4-Dihydro-4-methyl-2H,6H-(1,3)thiazino( 2,3-b)quinazolin-6-ones and 2,3-Dihydro-3-methyl-5H-thiazolo(2,3-b) quinazolin-5-ones and Analogous Polycyclic Pyrimidinone Derivatives from Condensed 2-Alkenylthiopyrimidine-4(3H)-ones.-Acid-mediated cyclization of the 2-allylthiopyrimidinones (III) yields the thiazole derivatives (IV) whereas the corresponding crotylthiopyrimidinones (V) give the thiazine derivatives regioselectively. -(WIPPICH, P.; HENDREICH, C.; GUETSCHOW, M.; LEISTNER, S.; Synthesis (1996) 6, 741-747; Inst. Pharm.,

Matrix metalloproteinases are secreted from different cells as inactive zymogens. For their activation in vitro organomercurials may be used, the presence of which, however, can falsify activity assays and modulate the effects of the proteases in subsequent investigations. Here, we demonstrate the binding of human matrix metalloproteinase 1 to a thiophilic resin (mercaptoethylquinazolinedione derivatized agarose) and take advantage of this thiophilic interaction for the purification of organomercurial activated matrix metalloproteinase 1 from the supernatant of a thyroid carcinoma cell line in connection with the simultaneous removal of the activator.