Gioia Zucchi

Product distribution in the microbial biogeneration of raspberry ketone from 4-hydroxybenzalacetone

Abstract The enzymic saturation of the double bond of 4-hydroxybenzalacetone 5 , of practical importance as an entry to the natural modification of raspberry ketone 6 , has been studied using a variety of microorganism.

On the stereochemistry of the Baeyer-Villiger degradation of arylalkylketones structurally related to raspberry ketone by Beauveria bassiana

Abstract The mode of transformation in Beauveria bassiana (ATCC 7159) of ketones 5–9 and 16 has been studied and compared with that of C-6--C-4 2, which through raspberry ketone 1 gives rise to C-6--C-2 tyrosol 3. Of the fed materials, only product 5 behaves as 2, i.e., is a good substrate for a formal Baeyer-Villiger chain-shortening transformation, which provides the secondary carbinol 10 enriched in the (S) enantiomer. Stereochemical analysis of the products obtained in the incubation of an authentic sample of (S) 5, obtained with bakers yeast upon reduction of the corresponding unsaturated ketone, indicates that the Baeyer-Villiger degradation leading to 10 occurs with kinetic preference for the (S) enantiomer and retention of configuration at the migrating carbon atom.

On the microbial biogeneration of (R) γ-jasmolactone

The biogeneration of (R) Z-7-decen-4-olide (γ-jasmolactone) (6) in Phichia stipitis and ohmeri from one of the products derived from linolenic acid via photooxidation/reduction is reported

Reduction of carboxylates to alkanols catalysed by Colletotrichum gloeosporoides

Sodium carboxylates (C6–C10) are effectively reduced to the corresponding alcohols by growing cultures of Colletotricum gloeosporoides in a preparatively useful way; intermediacy of the aldehydes is established by deuterium incorporation experiments; the unusual reducing capacity is proposed as an useful procedure for the preparation of alcohols of value as aroma components.

On the mode of biodegradation of cinnamic acids by Colletotrichum gloeosporoides: A direct access to 4-vinylphenol and 2-methoxy-4-vinylphenol

The mode of transformation by growing cultures of Colletotrichum gloeosporoides of C-6-C-3, unsaturated cinnamic acids 1, a-f depends upon the pattern of the oxygen substitution in the aromatic ring; from 1b and 1d are exclusively obtained upon decarboxylation the C-6-C-2 vinyl phenols 2b and 2d. whereas in the remaining instances the C-6-C-3 educts 3–5 formed by reduction are prevalent

Biogeneration of gamma nonanolide from coriolic acid in Pichia stipitis and Pichia ohmeri

Abstractγ-nonanolide in the (R) enantiomeric form is obtained, close to (R) δ-decanolide, as major transformation product of (R) coriolic acid in Pichia stipitis; feeding experiments of the (S) enantiomer lead to δ-decanolide as major metabolite

Stereochemistry of the conversion of (R) coriolic acid into δ-decanolide in Cladosporium suaveolens

SummaryIn growing cultures of Cladosporium suaveolens (R) coriolic acid (3) is converted into 5-decanolide enriched in the (S) enantiomer (2) (ca. 0.4 ee), while recovered coriolic acid shows the same enantiomeric composition of the precursor, as indicated by NMR studies onto a set of (+)-MTPA derivatives.

On the soybean type-I lipoxygenase-mediated conversion of linoleic acid into (S)-2-nonen-4-olide

Abstract(S) 2-nonen-4-olide3 of 0.5ee is obtained upon steam distillation from linoleic acid1 treated with oxygen at pH 9.6 in the presence of soybean type-I lipoxygenase; the two enantiomers of 2-nonen-4-olide obtained from [12, 13-2H2]1 were shown by multidimensional GC/MS to contain both 70% d2 and 30% d1 species