Abstract:
The work presented in this thesis is divided into three
separate sections 4!> Each' 'section is involved wi th a different
problem, however all three are involved with a microbial
oxidation of a substrate~
A series of 'aryl substituted phenyl a.nd be,nzyl methyl
sulphides were oxidized to the corre~pondi~g sulphoxides by
'Mo:rtierellai's'a'b'e'llina NRR.L17'S7 @ For this enzymic Qxidation,
based on 180 labeled experiments, the oxygen atom is derived
fr'orn the atmosphere and not from water. By way of an u~.traviolet
analysis, the rates of oxidation, in terms of sulphox~
de appearance, were obtained and correlated with the
Hatnmett p s~grna constants for the phenyl methyl sulphide
series. A value of -0.67 was obtained and, is interpreted in
terms of a mechanism of oxidation that involves an electrophilic
attack on the sulphide sulphur by an enzymic ironoxygen
activated complex and the conversion of the resulti!lg
sulphur cation to sulphoxide.
A series of alkyl phenyl selen~des have been incubated
with the fu~gi, Aspergillus niger ATCC9l42, Aspergillus
fO'etidus NRRL 337, MIIJisabellina NF.RLl757 and'He'lminth'osparium
sp'ecies NRRL 4671 @l These fu?gi have been reported to
be capable of carrying out the efficient oxidation of sulphide
to sulphoxide, but in no case was there any evidence to
supp'ort the occurrence of a microbialox,idation. A more
extensive inves·t~gation was carried out with'M,e 'i's'a'b'e'l'l'i'na,
this fu~gus was capable of oxidizing the correspondi~g sulphides to sulphoxi.de·s·$ Usi:ng a 1abel.edsubstra.te,
[Methyl-l4c]-methyl phenyl selenide, the fate of this compound
was invest~gated followi!lg an i'ncubation wi th Me isabellina ..
BeSUldes th. e l4C-ana1YS1Q S-,'. a quant"ltta"lve selen'lum ana1Y"S1S
was carried out with phenyl methyl selenide. These techniques
indicate that thesel'enium was capable of enteri!1g thefu!1gal
cell ef'ficiently but that s'ome metabolic cleav~ge of the
seleni'um-carbon bond' may take plac'e Ie
The
l3c NMR shifts were assigned to the synthesized
alkyl phenyl sulphides and selenides@
The final section involved the incubation ofethylben~
zene and p-e:rtr.hyltoluene wi th'M ~ 'isab'e'llina NRRL 17574b Followi~
g this incubation an hydroxylated product was isolated from
the medium. The lH NMR and mass spectral data identify the
products as I-phenylethanol and p-methyl-l-phenylethanol.
Employi!lg a ch'iral shift re~gent,tri~ (3-heptafluorobutyl-dcamphorato)'-
europium III, the enantiomeric puri ty of these
products was invest~gated. An optical rotation measurement
of I-phenylethanol was in ~greement with the results obtained
with the chiral shift re~gen,te 'M.isabe'l'lina is capable of
carryi~g out an hydroxylation of ethylbenzene and p-ethyltoluene
at the ~ position.
