4-Nitrobenzo-2-oxa-l,3-diazole

Phenols 7-Chloro-4-nitrobenzo-2-oxa-l,3-diazole (NBD chloride) Fluorescent 4-nitrobenzofuran derivatives are produced. Primary and secondary aromatic amines and thiols also react. [3]... 

Watanabe Y, Imai K (1981) High-performance liquid chromatography and sensitive detection of amino acids derivatized with 7-fluoro-4-nitrobenzo-2-oxa-l,3-diazole. Anal Biochem 116 471—472... 

Another series of probes which has attracted much interest in membrane studies has been the 2-A-(4-nitrobenzo-2-oxa-l,3-diazole) (NBD)-labeled lipids. These have been used for studies of the lipid trafficking in intact cells using mainly fluorescence microscopic techniques(77), for fluorescence quenching 78-791 and for studies of phospholipase A2 activities in membranes.(80) To date, they have received less attention in the study of lipid dynamics. 

A more comprehensive approach was reported in 1975 by Brabander and Verbeke (612). In this method, tissue samples were extracted with methanol and the acidified extract defatted with petroleum ether to be loaded onto a Dowex 50W-X8 anion-exchange resin. Following elution with aqueous methanol, the concentrated buffered extract was further defatted with diethyl ether. The sample was derivatized with 7-chloro-4-nitrobenzo-2-oxa-l,3-diazole (NBD-Cl) to be further spotted on a silica high-performance thin-layer chromatographic plate developed in two dimensions using chloroform/ethanol and chloroform/propionic acid consecutively as eluents. Detection of the propylthiouracil, phenylthiouracil, and tapazole residues was carried out on the basis of the fluorescence induction of the NBD derivatives of the drugs with an alkaline cysteine solution. 

Abbreviations CDNB, l-chloro-2,4-dinitrobenzene GSH, glutathione GS-DNB, l-(S-glutathionyl)-2,4-dinitrobenzene GST, glutathione-S-transferase NBD-C1, 7-chloro-4-nitrobenzo-2-oxa-l,3-diazole EA, ethacrynic acid. 

Example 13.3. I.-o -DPPC (Dipalmitoylphosphatidylcholine) has a critical film pressure of 7rc = 12 mN/m on water at 22° C. The dye, in this case NBD-DPPC (NBD 4-nitrobenzo-2-oxa-l,3-diazole), is expelled from the better ordered LC domains of DPPC (dark) and is enriched in the fluid LE-region (bright). The different phases can clearly be seen in the fluorescence image of Fig. 13.6. Upon compression, more and more of the dark appearing LC-domains will form until nearly all of the film becomes dark. 

Wakabayashi, S., Imagawa, T., Shigekawa, M. (1990). Does fluorescence of 4-nitrobenzo-2-oxa-l,3-diazole incorporated into sarcoplasmic reticulum ATPase monitor putative ErE2 conformational transition . Biochem. 107,563-571. 

H -ATP-synthase was postulated in view of the evidence that illumination [58,59], respiration [60] or artificially imposed ApH of the right direction (inside alkaline) [61] can increase the ATP level in halobacterial cells. This process was shown to be sensitive to A-ethylmaleimide, nitrate, A, A -dicyclohexylcarbodiimide (DCCD) and 7-chloro-4-nitrobenzo-2-oxa-l,3-diazole (NBD-Cl), and resistant to vanadate and azide. The same inhibitor pattern was found to be inherent in 350 kDa ATPase isolated from H. halobium[63] and H. saccharovorum [64,65],... 

The effect of cholesterol on lateral diffusion has also been studied. Rubenstein and co-workers [50] have found that the lateral diffusion of a fluorescent labelled phosphoUpid, phosphatidyl-iV-(4-nitrobenzo-2-oxa-l, 3-diazole)ethanolamine, exhibited an abrupt change in its lateral diffusion coefficient at 20 mole% cholesterol in a binary mixture of cholesterol and dimyristoylglycerophosphochoUne. Two explanations for this behaviour have been proposed based on the existence of ordered microscopic domains characterised by ripples or strips of solid phase interspread with the more fluid domains of the phosphoUpid-cholesterol complex [51-53]. Such a structure would form barriers to free lateral diffusion. An alternative... 

During research on antileukemic compoimds having the 4-nitrobenzo-2-oxa-l, 3-diazole (NBD) moiety, Ghosh and Whitehouse noticed that some... 

Ghosh PB, Whitehouse MW. 7-Chloro-4-nitrobenzo-2-oxa-l,3-diazole a new fluori-genic reagent for amino acids and other amines. Biochem J 1968 108 155-6. 

---