Candida lipolytica synthesizes the antibiotic tryptanthrin from 1 mole tryptophan and 1 mole anthranilic acid. When feeding tryptophan and substituted anthranilic acids, or substituted tryptophans and anthranilic acid, we could isolate and identify the expected derivatives of tryptanthrin. The enzymes of the biosynthesis of tryptanthrin, with the exception of bromotryptophan, had no specifity for these substrates. In addition to these experiments substituted tryptanthrines were chemically synthesized. We checked them for antibiotic action; the halogen compounds turned out to be especially effective.
The impact of substituting Hg(II)
for Zn(II) in a thiolate-bridged
trinuclear cluster with parallels to a metallothionein metal cluster
was investigated. A new solvomorph of [Zn(Zn
L
)
2
](ClO
4
)
2
(
1
) (
L
=
N
-(2-pyridylmethyl)-
N
-(2-(ethylthiolato)-amine)
and five solvomorphs of a new compound [Hg(Zn
L
)
2
](ClO
4
)
2
(
2
) were characterized
by single-crystal X-ray crystallography. The interplay of hydrogen
bonding and aromatic-packing interactions in producing lamellar, 2D
lamellar, and columnar arrangements of complex cations in the crystalline
state is discussed. Both variable temperature proton nuclear magnetic
resonance and electrospray ion-mass spectrometry (ESI-MS) suggest
that the complex ions of
1
and
2
are the
predominant solution species at moderate concentrations. ESI-MS was
also used to monitor differences in metal ion redistribution as
1
was titrated with Hg(ClO
4
)
2
and [Hg
L
(ClO
4
)]. These studies document the facile replacement
of Zn(II) by Hg(II) with the preservation of the overall structure
in thiolate-rich clusters.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.