Substrates and yields

In vegetables, natural microflora may consist of various genera of bacteria, yeasts, and molds. The organic acid content of a tomato is responsible for the low pH of between 4.0 and 4.6 (Gutheil, Price, and Swanson, 1980 Sajur, Saguir, and Manca de Nadra, 2007). Sorbic acid and perbenzoic acid are found in particularly high levels in several wild berries (Piper, 1999). 

Acetic acid is one of the main products of AAB metabolism and is found in many foods as the result of the presence and activity of these bacteria. Acetic acid is also a major volatile acid in wine but also one of the 

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Most biphasic systems use sparingly water-soluble substrates and yield hydrophobic products. Therefore, the aqueous phase serves as a biocatalyst container [34,35]. However, in some systems, one of the reactants (substrate or product) can be soluble in the aqueous phase [23,36-38]. 

Biocatalysis localization in the biphasic medium depends on physicochemical properties of the reactants. When all the chemical species involved in the reaction are hydro-phobic, catalysis occurs at the liquid-liquid interface. However, when the substrate is hydrophobic (initially dissolved in the apolar phase) and the product is hydrophilic (remains in the aqueous phase), the reaction occurs in the aqueous phase [25]. The majority of biphasic systems use sparingly water-soluble substrates and yield hydrophobic products therefore, the aqueous phase serves as a biocatalyst container [34,35] [Fig. 2(a)]. Nevertheless, in some systems, one of the reactants (substrate or product) can be soluble in the aqueous phase [23,36-38] (Fig. 2(b), (c)). 

Involvement of one, two, three, or four substrates or products is signified by combining two of the terms Uni, Bi, Ter, and Quad, respectively. Therefore, a reaction using two substrates and yielding one product is referred to as a Bi-Uni reaction. 

Table 4 Substrates and yields for Zr-mediated pyrrole synthesis...

Most reactions in biological systems start with two substrates and yield two products. They can be represented by the bisubstratc reaction ... 

The type of reaction shown above can take place intramolecularly with a suitable substrate, and yield cyclic systems (150). 

Oxidation Potentials and Fluorescence Lifetimes of the Substrates and Yields for Photoamination... 

In a useful extension of the procedure, f-butyl bromoacetate 310 was used as the substrate and yielded fi-configured a-bromo-P-hydroxy esters 311 in excellent diastereoselectivity and high enantiomeric excess. The adduct to isobutyric aldehyde (311, R = CHMe2) served as an intermediate for obtaining the diastere-omeric (25,35)- and (2R,35)-3-hydroxyisoleucine by replacement of the bromine substituent against the amino group under net retention and inversion, respectively (Scheme 4.69) [152]. 

The aldol condensation uses aldehydes or ketones as substrates and yields p-hydroxycarbonyl compounds. 

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