Journal of the American Chemical Society,
Journal Year:
2020,
Volume and Issue:
142(23), P. 10506 - 10515
Published: May 20, 2020
Pyridoxal
phosphate
(PLP)-dependent
enzymes
can
catalyze
transformations
of
l-amino
acids
at
α,
β,
and
γ
positions.
These
are
frequently
involved
in
the
biosynthesis
nonproteinogenic
amino
as
building
blocks
natural
products
attractive
biocatalysts.
Here,
we
report
discovery
a
two-step
enzymatic
synthesis
(2S,6S)-6-methyl
pipecolate
1,
from
biosynthetic
pathway
citrinadin.
The
key
enzyme
CndF
is
PLP-dependent
catalyzes
(S)-2-amino-6-oxoheptanoate
3
that
equilibrium
with
cyclic
Schiff
base.
second
CndE
stereoselective
imine
reductase
gives
1.
Biochemical
characterization
showed
this
performs
γ-elimination
O-acetyl-l-homoserine
to
generate
vinylglycine
ketimine,
which
subjected
nucleophilic
attack
by
acetoacetate
form
new
Cγ-Cδ
bond
complete
γ-substitution
reaction.
displays
promiscuity
toward
different
β-keto
carboxylate
esters.
With
use
an
Aspergillus
strain
expressing
CndE,
feeding
various
alkyl-β-keto
esters
led
6-substituted
l-pipecolates.
expands
repertoire
reactions
be
catalyzed
enzymes.
Chemical Reviews,
Journal Year:
2019,
Volume and Issue:
120(6), P. 3161 - 3209
Published: Dec. 23, 2019
Natural
nonproteinogenic
amino
acids
vastly
outnumber
the
well-known
22
proteinogenic
acids.
Such
are
generated
in
specialized
metabolic
pathways.
In
these
pathways,
diverse
biosynthetic
transformations,
ranging
from
isomerizations
to
stereospecific
functionalization
of
C–H
bonds,
employed
generate
structural
diversity.
The
resulting
can
be
integrated
into
more
complex
natural
products.
Here
we
review
recently
discovered
routes
freestanding
α-amino
acids,
with
an
emphasis
on
work
reported
between
2013
and
mid-2019.
Angewandte Chemie International Edition,
Journal Year:
2020,
Volume and Issue:
59(13), P. 5371 - 5375
Published: Jan. 20, 2020
Earth-abundant
nickel,
coordinated
with
a
suitable
chiral
bisphosphine
ligand,
was
found
to
be
an
efficient
catalyst
for
the
asymmetric
hydrogenation
of
2-amidoacrylates,
affording
α-amino
acid
esters
in
quantitative
yields
and
excellent
enantioselectivity
(up
96
%
ee).
The
active
component
studied
by
NMR
HRMS,
which
helped
us
realize
high
catalytic
efficiency
on
gram
scale
low
loading
(S/C=2000).
hydrogenated
products
could
simply
converted
into
acids,
β-amino
alcohols,
their
bioactive
derivatives.
Furthermore,
mechanism
investigated
using
deuterium-labeling
experiments
computational
calculations.
