Water-soluble activated ester

A water soluble activated ester of methoprene (Figure 5, Structure 16) was also prepared from sodium l-hydroxy-2-nitro-4-benzene sulfonate (16). The amount of compund 16 in crude preparations which contained both compound 16 and the free dianion (Figure 5, Structure 17) was determined by spectrophotometry in aqueous solution. Upon hydrolysis compound 16 yielded the dianion (Structure 17) which absorbed visible light at 406 nm in the presence of nucleophiles (Figure 5). Two absorbance readings were required to determine the amount of compound 16 present in the crude material. 

Figure 4. Preparation of the methoprene immunogen (Structure 15) by two methods a. The NHS-ester of methoprene (Structure 14) was conjugated to human serum albumin (H2N-HSA) in organic/aqueous solution, b. A water soluble active ester of methoprene (Structure 16) was prepared by the DCC coupling of methoprene-spacer acid (Structure 13) with l-hydroxy-2-nitro-4-benzene sulfonate. Reaction of compound 16 with H2N-HSA was carried out in aqueous phosphate buffered saline (PBS).

HOSu or NHS) or pentafluorophenol to give water-soluble activated esters, which can not be purified by extraction [30]. It has also been employed with sulfonamides to afford acylsulfonamide libraries, this last case requiring the addition of DMAP as additive [31]. The formation of thiol esters [32] and also the synthesis of ben-zoxazinone and benzoxatine scaffolds, via cyclodehydration, has been performed using PS-EDC (11) [33],... 

At the Hebrew University of Jerusalem, M. Frankel, Y. Wolman, Y.S. Klausner, C. Gilon and M. Chorev were engaged in the development of synthetic methods, such as the design and preparation of polymeric carbodiimides and water-soluble active esters. 

Vermeersch, H., J. P. Remon, D. Permentier, and E. Schacht. ItSQfto antitrichomonal activity of water-soluble prodrug esters of metronidazdht J. Pharm.60 253-260. 

Diethylaminopropyl)-3-ethylcarbodiimide ( water- 240 Active ester Water-soluble by-products ease work-up. 

Using the characteristic of a high-affinity complex between avidin and biotin, biotinylated antibodies have wide applications in various immunochemical assays, especially where signal amplification is required. A method is described here for the biotinylation of immunoglobulins. The procedure utilizes water-soluble succinimidyl ester of biotin that reacts with primary amines of the lysine residues or the amino terminus on the antibody to form amide bonds. The method is simple and specific and results in stable conjugates retaining full immunologic activity. 

Lynch et cd. [46] demonstrated that negatively charged water-soluble active keto-profen was incorporated with positively charged surfactants into a cubic liquid crystal. This study revealed that cationic surfactants such as dioctadecyl(dimethyl) ammonium chloride (DODMAC) and (dioctadecyl)ammonium chloride (DOAC) and di(canola ethyl ester)(dimethyl)ammonium chloride (DEEDAC) can be incorpo-... 

Ketopregnan-21-oic Acids, the 17(3-Carboxy Androstanes, and the D-Homocorticoids. In the course of studies on the metabohsm of fluocoitolone (103) the formation of the water-soluble carboxyhc acid (105, R = H) was reported. As a free 21-hydroxyl is not necessary for antiinflammatory activity, it was concluded that the esters (105, R = alkyl) of the preceding metabohte would possess antiinflammatory activity on topical administration but would be devoid of systemic activity when hydrolysis to the free acid occurs followed by... 

In addition to their poor solubility in water, alkyl phosphate esters and dialkyl phosphate esters are further characterized by sensitivity to water hardness [37]. A review of the preparation, properties, and uses of surface-active anionic phosphate esters prepared by the reactions of alcohols or ethoxylates with tetra-phosphoric acid or P4O10 is given in Ref. 3. The surfactant properties of alkyl phosphates have been investigated [18,186-188]. The critical micelle concentration (CMC) of the monoalkyl ester salts is only moderate see Table 6 ... 

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