Pseudomonas sp

A number of pyrrolnitrin analogues have been synthesized.  

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PPL and Hpase from Pseudomonas sp. catalyze enantioselective hydrolysis of sulfinylalkanoates. For example, methyl sulfinylacetate (46) was resolved by Pseudomonas sp. Hpase in good yield and excellent selectivity (62). This procedure was suitable for the preparation of sulfinylalkanoates where the ester and sulfoxide groups are separated by one or two methylene units. Compounds with three methylene groups were not substrates for the Hpase (65). 

Two more examples ia Table 5 iaclude the hydrolysis of esters of trans-alcohols that proceed with high efficiency practically regardless of the nature of the substituents (72) and resolution of P-hydroxynitriles with Upase from Pseudomonas sp. In the latter case the enantioselectivity of the hydrolysis was improved by iatroduciag sulfur iato the acyl moiety (73). 

The nature of the product strongly depends on the length of the hydroxy acid generally when the hydroxyl group is remote the yield of lactone drops significantly. For example, 10-hydroxydecanoic acid [1679-53-4] does not produce any decanoUde instead, the reaction proceeds by intermolecular oligomerization, and a complex mixture of di-, tri-, tetra-, and pentalactones results (90). However, when Pseudomonas sp. or Candida iylindracea]i 2Lses are incubated with 16-hydroxyhexadecanoic acid [506-13-8] hexadecanoUde is the predorninant product (91). 

Lipase-catalyzed intermolecular condensation of diacids with diols results in a mixture of macrocycUc lactones and liuear oligomers. Interestingly, the reaction temperature has a strong effect on the product distribution. The condensation of a,(D-diacids with a,(D-dialcohols catalyzed by Candida glindracea or Pseudomonas sp. Upases leads to macrocycUc lactones at temperatures between 55 and 75°C (91), but at lower temperatures (<45°C) the formation of oligomeric esters predorninates. Optically active trimers and pentamers can be produced at room temperature by PPL or Chromobacterium viscosum Upase-catalyzed condensation of bis (2,2,2-trichloroethyl) (+)-3-meth5ladipate and 1,6-hexanediol (92). 

The lipase from Pseudomonas sp. KIO has also been used to cleave the chloroacetate, resulting in resolution of a racemic mixture since only one enantiomer was cleaved. 

These compounds showed a remarkable activity toward Gram-positive (e.g.. Bacillus cereus, Staphylococcus aureus, Sarcina luted) and Gram-negative bacteria (e.g.. Pseudomonas sp.) the activity was somewhat lower in the styryl derivatives (82MI2). 

Further studies of Pseudomonas sp. lipase revealed a strong influence of the water content of the reaction medium (Entry 20) [48]. To be able to compare the enzyme activity and selectivity as a function of the water present in solvents of different polarities, it is necessary to use the water activity (a ) in these solvents. We used the... 

Typical batch production of succinoglycan by a Pseudomonas sp is shown in Figure 7.6. 

Figure 7.6 Production of succinoglycan in batch culture using a Pseudomonas sp. Bacterial dry weight ( ) succinoglycan concentration ( ) residual glucose ( ) residual ammonia (A). Adapted from as Figure 7.5.

Ketogluconic acid Pseudomonas sp. Intermediate for D-araboascorbic acid... 

The oxidation of norbornadiene and some derivatives using Pseudomonas sp [96]. 

Enzyme-catalyzed stereoselective hydrolysis allows the preparation of enantio-merically enriched lactones. For instance. Pseudomonas sp. lipase (PSL) was found to be a suitable catalyst for the resolution of 5-undecalactone and 5-dodecalactone (Figure 6.20). Relactonization of the hydroxy acid represents an efficient method for the preparation of both enantiomers of a lactone [67]. 

Styrene was successfully oxidized to the S-product both by xylene monooxygenase from P. putida mt-2 [113] and styrene monooxygenase from Pseudomonas sp.VLB120 [114] (Scheme 9.13), with the latter enzyme displaying a particularly large substrate tolerance with excellent stereoselectivity (>99% ee). In this context it is interesting to note that both xylene monooxygenase as well as chloroperoxidase are very selective for mono-epoxidation in case of presence of multiple alkene functionalities [115]. 

Organism bovine heart spinach Pseudomonas sp. NCIB 9816-4 E. coli (expression)... 

Lipase from C.antarctica also catalyzes carbon-carbon bond formation through aldol condensation of hexanal. The reaction is believed to proceed according to the same mechanism as the Michael additions [113]. Lipase from Pseudomonas sp. 

Yasumoto et al. (30) describe two components of a Pseudomonas sp. culture with identical HPLC retention times to TTX and anhydro-TTX. These fractions produced typical signs of TTX intoxication in mice, with median death times similar to standard TTX and anhydro-TTX. Noguchi et al. (32) demonstrate by HPLC and GC-MS analyses that 7 biotypes of Vibrio sp. produced substances with retention times and molecular weights similar to TTX and anhydro-TTX. However, they observed mouse toxicity in only 1 biotype. Likewise, Simidu et al. (34) report that extracts of V. alginolyticus ATCC 17749 cultures displayed TTX-like toxicity in mice. The latter study shows that a variety of marine bacteria, plus E. coliy produced substances that, by HPLC analysis, were identical to TTX and anhydro-TTX. 

Chromatographic Characterization of TTXs. The vast majority of reports have identified TTX and anhydro-TTX in bacterial cultures using HPLC, TLC, and GC-MS. Yasumoto et al. (30) showed that TTX-like substances extracted from a Pseudomonas sp. culture could bind to activated charcoal at pH 5.5 and be eluted with 20% ethanol in 1% acetic acid. In addition, HPLC analysis demonstrated TTX and anhydro-TTX-like fluorophors following strong base treatment. These compounds migrated on silica gel comparably to TTX and anhydro-TTX. Furthermore, when analyzed by electron ionization (EI)-MS and fast atom... 

If common marine bacteria, such as Vibrio sp. and Pseudomonas sp., indeed produce TTXs, it might be expected that more animals, particularly those living in aquatic environments, would be toxic. However, apparently only specific animals can concentrate TTX and/or provide a niche for TTX-producing bacteria. 

Five-membered unsubstituted lactone, y-butyrolactone (y-BL), is not polymerized by conventional chemical catalysts. However, oligomer formation from y-BL was observed by using PPL or Pseudomonas sp. lipase as catalyst. Enzymatic polymerization of six-membered lactones, 8-VL and l,4-dioxan-2-one, was reported. 8-VL was polymerized by various lipases of different origins. The molecular weight of the enzymatically obtained polymer was relatively low (less than 2000). 

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