ApoE secretion modulating bromotyrosine derivative from the Australian marine sponge Callyspongia sp.

Article abstract of DOI:10.1016/j.bmcl.2014.05.054

High throughput screening of a pre-fractionated natural product library identified 11 active fractions showing ApoE modulation activity. Mass-directed fractionation of one active crude extract from the Australian marine sponge Callyspongia sp. resulted in the isolation of 13 metabolites, including three new bromotyrosine derivatives, callyspongic acid (1), 3,5-dibromo-4- methoxyphenylpyruvic acid (2), N-acetyl-3-bromo-4-hydroxylphenylethamine (3), and ten known compounds (4-13). The structure elucidation of compounds 1-3 was based on their 1D and 2D NMR and MS spectroscopic data. 3,5-Dibromo-4- methoxyphenylpyruvic acid (2) showed weak activity in increasing the apolipoprotein E secretion from human CCF-STTG1 cells at the concentration of 40 μM.

Full text of DOI:10.1016/j.bmcl.2014.05.054

Accepted Manuscript
ApoE secretion modulatingbromotyrosinederivative from the Australian marine
sponge Callyspongiasp
Li-Wen Tian, Yunjiang Feng, Yoko Shimizu, Tom A. Pfeifer, Cheryl
Wellington, John N.A. Hooper, Ronald J. Quinn
PII:
S0960-894X(14)00554-X
http://dx.doi.org/10.1016/j.bmcl.2014.05.054
BMCL 21668
DOI:
Reference:
To appear in:
Bioorganic & Medicinal Chemistry Letters
Received Date:
Revised Date:
Accepted Date:
8 April 2014
13 May 2014
15 May 2014
Please cite this article as: Tian, L-W., Feng, Y., Shimizu, Y., Pfeifer, T.A., Wellington, C., Hooper, J.N.A., Quinn,
R.J., ApoE secretion modulatingbromotyrosinederivative from the Australian marine sponge Callyspongiasp,
Bioorganic & Medicinal Chemistry Letters (2014), doi: http://dx.doi.org/10.1016/j.bmcl.2014.05.054
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Graphical Abstract
ApoE secretion
modulatingbromotyrosinederivative from the
Australian marine sponge Callyspongiasp.
Leave this area blank for abstract info.
Li-Wen Tian, Yunjiang Feng, Yoko Shimizu, Tom A. Pfeifer, CherylWellington, John N. A. Hooper, Ronald J.
Quinn

Bioorganic & Medicinal Chemistry Letters
journal hom epage: www.elsevier.com
ApoE secretion modulatingbromotyrosinederivative from the Australian marine
sponge Callyspongiasp.
a
a
b
b
c
d
Li-WenTian , YunjiangFeng , Yoko Shimizu , Tom A. Pfeifer , CherylWellington , John N. A. Hooper , and
a,∗
Ronald J.Quinn
a
Eskitis Institute, Griffith University, Brisbane, QLD 4111, Australia
b
Centre for Drug Research and Development, Vancouver, BC, V6T 1Z3, Canada
c
Department of Pathology and Laboratory Medicine, University of British Columbia,Vancouver, BC V6T 1Z4, Canada
d
QueenslandMusuem, South Brisbane, QLD 4101, Australia
ARTICLE INFO
ABSTRACT
Article history:
Received
High Throughput Screening of a pre-fractionated natural product library identified 11 active
fractions showing ApoE modulation activity.Mass-directed fractionation of oneactivecrude
extract from the Australian marine sponge Callyspongia sp. Resulted in the isolation of 13
metabolites, including three new bromotyrosine derivatives, callyspongic acid (1),
3,5-dibromo-4-methoxyphenylpyruvic acid (2), N-acetyl-3-bromo-4-hydroxyphenylethamine (3),
and ten known compounds (4-13). The structure elucidation of compounds 1-3 was based on their
1D and 2D NMR and MS spectroscopic data. 3,5-dibromo-4-methoxyphenylpyruvic acid (2)
showed weak activity in increasing the apolipoprotein E secretion from human CCF-STTG1
cellsat the concentration of 40 µM.
Revised
Accepted
Available online
.
Keywords:
Callyspongia sp.
Bromotyrosine derivatives
bastadin
2
009 Elsevier Ltd. All rights reserved.
ApoE modulation activity
∗
Corresponding author. Tel.: +61-7-37356000; fax: +61-7-37356001; e-mail: r. quinn@griffith.edu.au

Alzheimer’s disease (AD) has emerged as the most prevalent
form of late-life mental disorder in humans and is typified by
deposition of β-amyloid (Aβ) with the brain. Aβ is a neurotoxic
mg, 0.004% dry wt), and comantherin(6, 1.0 mg, 0.005% dry wt).
Further purification of the fractions 33-36 with a Luna
1
C
18semi-preparative
column
yielded
peptide and the accumulation of Aβ leads to its deposition into
plaques and the launching of a pathologic cascade that ultimately
leads to neuronal death. An impaired ability to clear Aβ peptides
3,5-dibromo-4-methoxyphenyl- aceticacid(6, 0.8 mg, 0.004% dry
wt), bastadin18(12, 0.4 mg, 0.002% dry wt), and bastadin 24(13,
0.4 mg, 0.002% dry wt). Repeated chromatography of 50%
1
from the brain, rather than increased production of Aβ peptides, is
thought to underlie most cases of late-onset AD.
MeOH/H
2
O fraction on reverse phase C18-bonded HPLC and Luna
2
C18 semi-preparative HPLC yieldedbastadin 6(7, 0.4 mg, 0.002%
Apolipoprotein E (ApoE) is the major apolipoprotein in the
central nervous system that plays a central role in cholesterol
3
transport. In the brain, ApoE is mostly produced by astrocytes,
and some of ApoE binds to specific neuronal receptors for
3
cholesterol uptake. A previous study suggested that increased
levels of highly lapidatedApoE could facilitate the clearance of Aβ
4
, 5
peptides, implying that the interference of ApoE secretion could
potentially lead to the treatment of Alzheimer's disease.
Bexarotene is the only reported compound used clinically that is
5
known to activate ApoE expression.
In our ongoing search for new lead compounds for
neurodegenerative disorders, a drug discovery program was
initiated to identify natural products as ApoE modulators. A high
throughput screening method was developed and used to screen
EskitisInstitute’s pre-fractionated natural product library of
1
from the human derived astrocytoma cell line CCF-STTG1, used
02,432 fractions for their ability to modulate ApoE secretion
6
extensively in Alzheimer research. Eleven fractions were
identified with concentration dependent activity forApoE
enhancement over background levels, albeit at high concentrations.
One of the 11 fractions was derived from an extract of the
Australian sponge Callyspongia sp.(-)-LRESIMS of the active
fraction showed molecular ions at m/z349/351/353, 321/323/325,
which were predicted to correspond to bioactive natural products.
2 2
Mass-directed fractionation of the CH Cl /MeOH extract led to
the isolation of 13 compounds, including three new bromotyrosine
dry wt), bastadin 7
8, 0.3 mg, 0.0015% dry wt), bastadin 8 (9, 0.50 mg, 0.0025% dry
derivatives, callyspongic
3,5-dibromo-4-methoxyphenylpyruvic
acid
acid
(1),
(2),and
(
wt), bastadin 9 (10, 0.30 mg, 0.0015% dry wt), andbastadin 16 (11,
.6 mg, 0.003% dry wt).
N-acetyl-3-bromo-4-hydroxylphenylethamine (3), together with
ten known natural products, N-acetyl-3,5-dibromo-4-hydroxyl
0
7
(4), 3,5-dibromo-4-methoxyphenylacetic
15
Callyspongic acid (1) was obtained as a brown amorphous
phenylethamine
8
acid(5), comantherin (6), bastadin 6 (7), bastadin 7 (8), bastadin
9
10
10
powder. The cluster of four isotopic ions at m/z607/609/611/613
(1:3:3:1) in (+)-LRESIMS indicated the presence of three bromine
atoms in the molecule. The molecular formula, C H Br N O ,
1
(9), bastadin 9 (10), bastadin 16 (11), bastadin 18 (12), and
1
11
12
13
8
bastadin 24 (13). Herein we report the isolation and structure
14
19
17
3
2
6
+
elucidation
3
of
,5-dibromo-4-methoxyphenylpyruvic
callyspongic
acid
(1),
acid
was established on the basis of HRESIMS (m/z628.8529 [M+Na] ,
7
9
19 3 2 6
calcd628.8532 for C H17 Br N O Na), with 11degrees of
1
unsaturation. The Hand gHSQCNMRdata analysis suggested
(2),andN-acetyl-3-bromo-4-hydroxylphenylethamine (3), as well
as the ApoE modulation activities of compounds 1 -13.
thatcompound 1contained three exchangeable protons (δ 12.11, s;
H
9
.98, s;and 7.87, d, J = 7.9 Hz), fivearomatic protons (δ
H;7.23, d, J = 2.1 Hz, 1H;6.92, dd, J = 8.3, 2.1 Hz, 1H; and 6.79,
4.44, m), two methylenes (δ
.73, d, J = 14.2 Hz, H-7'a; 3.70, d, J = 14.2 Hz, H-7'b; 3.00, dd, J
H
7.40, s,
The freeze-dried and ground marine sponge (20.0 g) was
2
sequentially extracted with n-hexane, CH
CH Cl and MeOH extracts were combined and chromatographed
on reverse phase C18 flash column, eluting with 10% MeOH/H O,
O, and 100% MeOH. The 10%
O was fractionatedusing reversephase C18-bonded silica
O/0.1% TFA) to yield 60 fractions. Fractions
2-25 and 29 contained the ions of interest, and
yielded3,5-dibromo-4-methoxyphenylpyruvic acid(2, 2.0 mg,
2 2
Cl and MeOH. The
d, J = 8.3 Hz, 1H), one methine (δ
3
H
H
2
2
2
=
5.0, 14.0 Hz, H-7a; and 2.95, dd, J = 8.2, 14.0 Hz, H-7b), and
3.74, s). The gCOSY correlation data (Fig. 1)
1,3,4-trisubstituted benzene moiety and an
ethylamine group: NH-CH-CH .gHMBC experiment revealed the
correlations from theexchangeable proton (δ 9.98) tothree
aromatic carbons (δ 109.4, C-3;153.3, C-4; and 116.6, C-5),
suggesting that the hydroxyl group was attached to the C-4 of the
,3,4-trisubstituted benzene moiety. gHMBC correlations from
the methylene (δ 3.00,H-7a; 2.95, H-7b)in the ethylamine group
to the three aromatic carbons (δ 130.1, C-1; 133.7, C-2; and
29.8, C-6) indicated that the ethylamine group was connected to
the 3-bromo-4-hydroxybenezene moiety. gHMBC correlations
from H-7 (δ 3.00, 2.95) and H-8 (δ 4.44) to a carboxyl carbon (δ
73.2) suggested that the methine H-8 from the ethylamine group
3
2 2
0% MeOH/H O, 50% MeOH/H
one methoxy (δ
established
H
MeOH/H
2
a
HPLC (MeOH/H
2
2
2
H
C
0
0
.01% dry wt), and 3,5-dibromo-4-methoxyphenylacetic acid(5,
.6 mg, 0.003% dry wt), respectively. Purification of fraction 34
1
with a Luna C18 semi-preparative HPLC column yielded
callyspongic acid (1, 0.2 mg, 0.001% dry wt). The 30%
H
C
MeOH/H
C
2
Ofraction was further purified by reversephase
O/0.1% TFA) to yield 60
1
18-bonded silica HPLC (MeOH/H
2
fractions. Fractions 16, 34 and 46 resulted in pure compounds
N-acetyl-3-bromo-4-hydroxylphenylethamine(3, 0.4 mg, 0.002%
dry wt), N-acetyl-3,5-dibromo-4-hydroxyl phenylethamine(4, 0.8
H
H
1

1
13
6
Table 1 H (600 M) and C (150 M) NMR data for compounds 1-3 (DMSO-d )
Position
1
2
HMBC
3
δ
H
δ
c
HMBC
δ
H
δ
133.4
c
δ
H
c
δ HMBC
1
2
3
4
5
6
7
130.1
129.4
7.23 d (2.1)
133.7 C3, 4, 6, 7
109.4
153.3
116.6 C3, 4, 6
129.8 C1, 4, 5
8.03 s 133.6 C1, 3, 4, 7
7.28 d (2.2)
133.2 C1, 3, 4, 7
109.6
152.9
116.7 C1, 3, 4
129.4 C2, 4, 5, 7
117.7
152.4
117.7
6.79 d (8.3)
6.92 dd (8.3, 2.1)
6.84 d(8.2)
6.98 dd(2.2, 8.2)
2.56 t(7.3)
8.03 s 133.6 C1, 3, 4, 7
6.33 s 106.5 C2, 8, 9
3.00 dd (14.0, 5.0) 35.2
.95 dd (14.0, 8.2)
C1, 2, 8, 9
34.4
C1, 2, 6, 8
2
4.44 m
8
9
54.1
173.2
136.7
C7, 9
143.8
166.3
3.18 t(7.3)
1.74 s
40.8
C1, 7, 1'
1
2
3
4
5
6
7
'
'
'
'
'
'
'
169.8
23.4
7.40 s
133.2 C3',6', 4', 7'
117.6
152.6
117.6
133.2 C2',3', 4', 7'
C1'
7.40 s
3.73 d (14.2)
28.3
C1',2', 8', 9'
3
.70 d (14.2)
8
9
'
'
151.1
163.3
60.9
OCH
OH
NH
3
3.74 s
9.98 s
7.87 d (7.9)
12.11 s
C4'
3.77 s 61.0
C3, 4, 5
C8, 9'
C8'
9.94 s
7.82 t(5.6)
C1'
N-OH
2
3
was connected to a carboxyl group. Thus a trisubstituted tyrosine
moiety was assigned. In addition, a two-proton singlet (δ 7.40),
characteristic of a symmetrical 1,3,4,5-tetrasubstituted benzene,
rotation of 1([α]D +3.63, c 0.008, MeOH) was compared with
23
H
those of L-3-bromotyrosine ([α]
-28, c 0.1, MeOH)
D
2
3
andD-3-bromotyrosine ([α]D +28, c 0.1, MeOH), indicating a
D-3-bromotyrosine moiety in 1. D/L-3-bromotyrosine was
prepared from corresponding tyrosine (Fig. 2).
showed gHMBC correlations to the quaternary aromatic carbons
(
δ
C
117.6, C-3', 5'; 152.6, C-4') and the methylene carbon (δ
C-7'), while the methylene (δ 3.73, H-7'a; 3.70, H-7'b) showed
gHMBC correlations with the aromatic carbons (δ 136.7, C-1';
33.2, C-2', 6'), and two quaternary carbons (δ 151.1, C-8'; 163.3,
C-9'), indicating an α-oximebenzenepropanamide. The gHMBC
correlation from the methoxy (δ 3.74, s) to the aromatic carbon
152.6) suggested that methoxy group was attached to the C-4
C
28.3,
H
C
1
C
H
(
C
δ
position of 1,3,4,5-tetrasubstituted benzene. The configuration of
the oxime was determined to be E by the diagnostic carbon
chemical shift of the benzylicmethylenes (δ
chemical shift of benzylic methylene corresponding to Z oximines
C
28.3). The carbon
17
,5-Dibromo-4-methoxyphenylpyruvic acid (2) exhibited a
3
1
6
are known to be >35 ppm. Finally theconnection of the
α-oximebenzenepropanamide with the substituted tyrosine
through an amide bond was established by thegHMBC
cluster of isotopic ions at m/z 349/351/353 (1:2:1) in the
-)-LRESIMS spectrum, indicating the presence of two bromine
atoms in the molecule. The molecular formula, C10 Br , was
established on the basis of HRESIMS (m/z 348.8716 [M-H] ,
(
H
8
2 4
O
correlations from the methine (δ
H
4.44, H-8) and the exchangeable
-
NH proton (δ 7.87) to thecarbonyl carbon (δ
H
C
79
calcd348.8710 for C10
H
7
Br
The H, and gHSQC NMR data of compound 2 showed a
two-proton singlet (δ 7.79; δ 133.6), representing a symmetrical
,3,4,5-tetrasubstituted benzene moiety, a methine singlet (δ 6.33;
106.5), and a methoxy (δ 3.77; δ 61.0). The aromatic
methine proton (δ 7.79) showed gHMBC correlations with the
aromatic carbons (δ 133.4, C-1; 117.7, C-3/5; and 106.5, C-7) and
2 4
O ), with six degrees of unsaturation.
163.3)inoximebenzenepropanamide moiety. Thus, the planar
structure of callyspongic acid was elucidated as 1.
1
H
C
1
H
Br
δ
C
H
C
H
O
H
Br
Br
C
HOOC
HO
2
a sp carbon (δ
C
106.5, C-7). The methinesinglet (δ
H
6.33)
133.6,
Br
Br
N
N
O
H
H CO
3
showed gHMBC correlations with aromatic carbon (δ
C
2
COOH
H CO
3
C-2/6), a sp carbon (δ
66.3, C-9). ThesegHMBC correlation data indicated that
compound was very similar to
-bromo-4-methoxyphenylpyruvic acid (enol
Themethoxy group was located on the C-4 of the benzene ring by
the gHMBC correlations from the methoxy proton (δ 3.77) to the
aromatic carbon (δ 152.4). Thus, the structure of 2 was assigned
as 3,5-dibromo-4-methoxyphenylpyruvic acid.
C
143.8, C-8), and a carbonyl carbon (δ
C
HO
1
2
gCOSY
gHMBC
18,
3
form).
1
9
Figure 1: Key gCOSY and gHMBC correlations of 1 and 2
H
C
The Marfey’s reaction was not performed on compound 1due
to limited amount of compound obtained. However, the optical

2
(3) was
0
N-acetyl-3-bromo-4-hydroxylphenylethamine
F.; Guido, T.; Hagopian, S.; Johnson-Wood, K.; Khan, K.; Lee,
M.; Leibowitz, P.; Lieberburg, I.; Little, S.; Masliah, E.;
McConlogue, L.; Montoya-Zavala, M.; Mucke, L.; Paganini, L.;
Penniman, E.; Power, M.; Schenk, D.; Seubert, P.; Snyder, B.;
Soriano, F.; Tan, H.; Vitale, J.; Wadsworth, S.; Wolozin, B.; Zhao,
J. Nature 1995, 373, 523.
isolated as brown amorphous powder. (+)-LRESIMS showed an
isotopic ion cluster at m/z 258/260 (1:1), indicating the presence of
one bromine atom in the molecule. The molecular formula of 3was
determined to be C10
H
12BrNO
79.9943 [M+Na] , calcd279.9940 for C10
and gHSQC NMR data of compound 3showed two exchangeable
protons (δ 9.94 s; 7.82, t, J = 5.6 Hz), three mutually coupled
aromatic protons (δ 7.28, d, J = 2.2 Hz, H-2; 6.98, dd, J = 2.2, 8.2
Hz, H-6; and 6.84, d, J = 8.2 Hz, H-5), two methylenes (δ 3.18, t, J
7.3 Hz; 2.56, t, J = 7.3 Hz), and a methyl group (δ 1.74 s). The
above data were very similar to those of
2
, on the basis of HRESIMS (m/z
+
79 1
2
2
H12 BrNO Na). The H,
2
3
4
.
.
.
Hardy, J.; Selkoe, D. J. Science 2002, 297, 353.
H
Kim, J.; Basak, J. M.; Holtzman, D. M. Neuron 2009, 63, 287.
Poirier, J.; Bertrand, P.; Kogan, S.; Gauthier, S.; Davignon, J.;
Bouthillier, D. The Lancet 1993, 342, 697.
H
H
=
H
5. Cramer, P. E.; Cirrito, J. R.; Wesson, D. W.; Lee, C. Y. D.; Karlo,
J. C.; Zinn, A. E.; Casali, B. T.; Restivo, J. L.; Goebel, W. D.;
James, M. J.; Brunden, K. R.; Wilson, D. A.; Landreth, G. E.
Science 2012, 335, 1503.
N-acetyl-3,5-dibromo-4-hydroxyl phenylethamine (4). The only
difference was that compound 3 had an 1,3,4-trisubstituted
benzene ring instead of a symmetrical 1,3,4,5-tetrasubstituted
benzene ring in 4. Hence,compound3 was assigned as
N-acetyl-3-bromo-4-hydroxylphenylethamine.
6
.
Fan, J.; Shimizu, Y.; Chan, J.; Wilkinson, A.; Ito, A.; Tontonoz, P.;
Dullaghan, E.; Galea, L. A. M.; Pfeifer, T.; Wellington, C. L. J.
Lipid Res.2013, 54, 3139-3150.
Ten
known
natural
products,
N-acetyl-3,5-dibromo-4-hydroxylphenylethamine
namely
(4),
7. Schoenfeld, R. C.; Conova, S.; Rittschof, D.; Ganem, B. Bioorg.
Med. Chem. Lett. 2002, 12, 823.
3
,5-dibromo-4-methoxyphenylacetic acid(5),comantherin (6),
bastadin 6 (7), bastadin 7 (8),bastadin 8 (9),bastadin 9
10),bastadin 16 (11),bastadin 18 (12),andbastadin 24 (13), were
also isolated from the marine sponge. Their structures were
identified by comparing their H and C NMR data with those
reported in the literature. Interesting,
,5-dibromo-4-methoxyphenylpyruvic acid (2) was the rare
example of natural occurring phenylpyruvic acid (enol)
derivatives. This is also the first report of the presence of bastadins
from the sponge Callyspongia sp.
8
.
Weller, D. D.; Stirchak, E. P.; Yokoyama, A. J. Org. Chem. 1984,
9, 2061.
9. Leeper, F. J.; Staunton, J. J. Chem. Soc., Perkin Trans. 1 1984,
919.
(
4
1
13
2
1
1
1
1
0. Kazlauskas, R.; Lidgard, R.; Murphy, P.; Wells, R.; Blount, J.
Aust. J. Chem. 1981, 34, 765.
3
1. Miao, S.; Andersen, R. J.; Allen, T. M. J. Nat. Prod. 1990, 53,
1441.
2. Park, S. K.; Jurek, J.; Carney, J. R.; Scheuer, P. J. J. Nat. Prod.
The ApoE modulatory activities of compounds 1-13 were
evaluated. 3,5-Dibromo-4-methoxyphenylpyruvic acid (2)was the
only active compound, increasingApoE secretion by one fold over
background at the concentration of 40 µM.
1994, 57, 407.
3. Jaspars, M.; Rali, T.; Laney, M.; Schatzman, R. C.; Diaz, M. C.;
Schmitz, F. J.; Pordesimo, E. O.; Crews, P. Tetrahedron 1994, 50,
7367.
In conclusion, thirteen compounds (1-13) were isolated from
the Australian marine sponge Callyspongia sp. Three compounds
1
1
4. Greve, H.; Kehraus, S.; Krick, A.; Kelter, G.; Maier, A.; Fiebig,
H.-H.; Wright, A. D.; König, G. M. J. Nat. Prod. 2008, 71, 309.
(
1-3) are new to science and 3,5-dibromo-4-methoxyphenyl-
5. Compound 1, isolated as brown amorphous powder; [α]
.008, CH OH); UV (CH OH) λmax (log ε) 282 (3.75), 211 (4.68)
nm; IR (KBr) νmax 3380, 2924, 2854, 1712, 1497, 1260, 1203
D
+3.63 (c
pyruvic acid (2) show weak ApoE modulation activities. It is the
first time that bastadins were isolated from the sponge
Callyspongia sp.
0
3
3
-
1 1
13
cm ; H and C NMR data see Table 1; HRESIMS m/z 628.8529
+
79
Acknowledgement
[
M+Na] (calcd for C19
6. Arabshahi, L.; Schmitz, F. J. J. Org. Chem. 1987, 52, 3584.
7. Compound 2, isolated as pale amorphous powder; UV (CH
max (log ε) 292 (3.54), 209 (4.39) nm; IR (KBr) νmax 3368, 2930,
3 2 6
H17 Br N O Na, 628.8532).
1
1
The authors thank H. Vu from Griffith University for
acquiring the HRESIMS measurement.This work was supported
by the Queensland Government Smart Futures NIRAP Program,
the Australian Research Council for NMR and MS equipment
3
OH)
λ
-
1
1
13
2582, 1764, 1706, 1267, 997 cm ; H and C NMR data see
79
-
Table 1; HRESIMS m/z 348.8716 [M-H] (calcd for C10
(
LE0668477 and LE0237908), in part by an operating grant from
H
7
Br
2
O
4
,
the Alzheimer’s Drug Discovery Foundation to CW, and
Innovation Funds from the Centre for Drug Research and
Development (Vancouver, Canada).
348.8711).
1
1
2
8. Hoshino, O.; Murakata, M.; Yamada, K. Bioorg. Med. Chem. Lett.
992, 2, 1561.
1
9. Tran, T. D.; Pham, N. B.; Fechner, G.; Hooper, J. N. A.; Quinn, R.
Supplementary data
J. J. Nat. Prod. 2013, 76, 516.
1
Supplementary data ( H, gCOSY, gHSQC, gHMBC NMR spectra
3
0. Compound 3, isolated as pale amorphous powder; UV (CH OH)
for
compounds
1-3,general
experimental
procedures,
λ
max (log ε) 283 (3.34), 210 (4.07) nm; IR (KBr) νmax 3274, 2927,
spongecollection and identification, extraction and isolation
procedures, Preparation of D-and L-3-bromotyrosine, ApoE
modulation activity assay) associated with this article can be
found, in the online version, at
-1
647, 1508, 1288, 1197 cm ; H and C NMR data see Table 1;
1
13
1
+
HRESIMS m/z 279.9943 [M+Na] (calcd for C10
79
2
H12 BrNO Na,
279.9940).
References and notes
1
.
Games, D.; Adams, D.; Alessandrini, R.; Barbour, R.; Borthelette,
P.; Blackwell, C.; Carr, T.; Clemens, J.; Donaldson, T.; Gillespie,