BAPTA structure

The structure of the fluorescent sensor Fluo-3 consists of BAPTA attached to a xanthene derivative as the fluorophore (Fig. 18.2). Many xanthene-based (sometimes referred to fluorescein-based) fluorescent sensors such as Fluo-3 have been reported. These compounds have an aromatic moiety that recognizes or reacts with the target at the 9-position of the xanthene ring. 

A) Molecular structure of the calcium chelator 5F-BAPTA whose F chemical shift changes upon calcium binding. (B) F NMR spectrum of a solution containing 5F-BAPTA and Ca in a molar ratio of 3 1. Signal B originates from the Ca +-5F-BAPTA complex, and F from free 5F-BAPTA. Adapted from Reference 29. 

Using BAPTA as the Ca -binding portum of the mdecule, three classes of fluorescoit compounds have beoi designed that could be useful as indicators of near-mmbrane Ca. The requirmnoits of a near-membrane indicator are diffomit frcmi those of cytoplasmic indicators, which are deagned to stay in the aqueous portion of the cdl. For example, fura-2 has a pdar carboxylate on die fluorophore to hdp prevent association of the dye with nonpolar structures. 

Insect sex pheromones have very simple structures like butyric acid, the aphrodisiac pheromone of the male moth Bapta temerata and valeric acid from Limonius californicus or more complex ones like peri-planone (118) one of the components of the sexual attractant of the American cockroach Periplaneta americana. 

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