Evaluation of benzofurazan derivatives as fluorogenic reagents for thiols and amines using high-performance liquid chromatography

Abstract

The reactivities of three reagents, 4-(N,N-dimethylaminosulphonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F), 4-( a m i nosu I p honyl)-7-f I uoro-2,1,3-benzoxadiazo le (ABD-F) and 4-(f I uorosu I p honyl)-7-p henoxy-2,1,3-benzoxadiazole (PBD-S02F), towards thiols and amines were compared. All three reacted with thiol compounds to give derivatives which fluoresced at ca. 51 5 n m (excitation at ca. 388 nm). However, the PBD-SOZ derivatives were not very stable. The rate of reaction of DBD-F with proline was faster than that of PBD-SOZF or ABD-F. The three reagents and their hydrolysates exhibited extremely low fluorescence. The fluorescence intensities of the proline derivatives synthesised were higher in neutral and acidic solutions than i n alkaline solution. The strength of the fluorescence intensities was in the order PBD-S02-proline > DBD-proline > ABD-proline a t all pH values tested. The mean values of the maximum wavelengths of DBD-proline, ABD-proline and PBD-SOz-proline were 596 n m (Aex, = 466 nm), 602 n m (Aex, = 466 nm) and 566 n m (Aex. 453 nm), respectively.Of the three reagents, DBD-F seemed to be applicable to the determination of amino acids. Nine amino acid derivatives of DBD-F were separated by reversed-phase high-performance liquid chromatography and detected with fluorescence at 590 nm (Aex. = 450 nm). The detection limits were in the sub-picomole range.

Development of Benzofurazan−bearing Fluorescence Labeling Reagents for Separation and Detection in High−performance Liquid Chromatography

“…For the determinations of the amine, complete reaction was achieved after 30 min at pH 9.3 and 50 . However, the reaction of amines with DBD−F was only 78% complete after 2 h under the same conditions [15]. The fluorescence intensity of the DBD−amine adducts was the highest at pH 2−3, and was 2.5 times higher than that of the corresponding ABD−amine adducts, but only 25% of the NBD−amine adducts.…”

“…However, that for dimethylsulfonamide (SO2NMe2) has not been established. Based on the structure, the electron withdrawing activity of dimethylsulfonamide may be higher than that of the sulfonamide group and less than the nitro group [15]. Based on these observations, the syntheses of ammo- (Fig.…”

“…SBD −F was first synthesized from the reaction of fuming sulfuric acid with 4−fluorobenzofurazan which is obtained from 2,6− difluoroaniline in two steps [16]. ABD−F and DBD−F was also obtained from the reaction of ammonia and dimethylamine, respectively, with 4−fluoro−7−chlorosulfonylbenzofurazan, derived from the reaction of 4−fluorobenzofurazan with thionylchloride (SO2 Cl2) [15,17]. and in organic solvents rather than in water [18].…”

Synthesis of 4-aryloxy-7-nitrobenzofurazan derivatives from 4-chloro-7-nitrobenzofurazan and various phenoxide anions (including pharmaceuticals) in the presence of crown ethers

“…Estrone 3-(7-nitrobenzofurazan) ether, 6a, described previously [36] with NMR data for comparison with the new compounds presented now: 18(m, 13H, H-estradiol); 0.83(s, 3H, H-18'). 13 …”

An Invitation to Bio-Analytical Chemistry

“…[59][60][61][65][66][67][68][69][70] They have been used not only for the determination of small biomolecules such as cysteine, glutathione in plasma and a drug (captopril) [71][72][73][74][75][76][77][78] , but also for thiol moiety determination of big molecules such as proteins and enzymes. 79,80 The reagent for alcohols, 261 ANALYTICAL SCIENCES APRIL 1998, VOL.…”