Chloropeptin

1. Discovery, producing organism and structures1-4)
During screening for new gp120-CD4 binding inhibitors from microorganisms, chloropeptins Iand II were isolated from the culture broth of the actinomycete strain WK-3419. While the major
component, chloropeptin I was identified as a novel compound, chloropeptin II was identified ascomplestatin5,6).
The planer structure of chloropeptin I was elucidated by NMR analysis1,4). The stereostructure
was elucidated by NOE experiments in combination with molecular dynamics conformation
analysis and Monte Carlo calculations2). The total synthesis of chloropeptin I was reported byDeng et al.8), Boger et al.9,10,12) and Zhu et al.11) (See Appendix I).
OH

O
HO

H
N
HOOCO
N
O H3 C

O

H
N

N
H

O

Cl

OH

Cl

HN

Cl
O

H
N
O

Cl

N
H

OH
Cl

O

Cl

OH

Chloropeptin IOHOHOStreptomyces sp. WK-3419

HN
HOOC

O
N
O H3 C
Cl

Cl
O

H
N

N
H

O

OH

Cl

Cl

HN
H
NO
O

OH

N
H

O

OH
Cl

Cl

Chloropeptin II (Complestatin)

2. Physical data (Chloropeptin I)
Pale yellow brown powder. C61H45N7O15Cl6; mol wt 1328.79. Sol. in DMSO, MeOH, alkaline
H2O, pyridine. Insol. in H2O, acetone, CHCl3.
3. Biological activity1,4,7)
1) Inhibition of gp120-CD4 binding
Compound

IC50 (µM)*

Chloropeptin I
Chloropeptin II (complestatin)

2.0
3.3

* Binding activity between recombinant soluble
CD4 and recombinant gp120 was determinedby ELISA.
2) Inhibition of HIV replication in the viral core protein level
Compound		None
Chloropeptin I (7.5 µM)

Viral core protein p24 synthesized (ng/ml)
Day 2Day 3Day 40097.30129.6
7.33) Anti-HIV-1 activities of chloropeptin I, complestatin, dextran sulfate, and AZT			
Compound		
Chloropeptin I
Complestatin
Dextran sulfate
AZT

CPE*		
EC50 (µM)

CC50 (µM)

SI

1.6
1.7
2.9 (µg/ml)
0.011

>600
530
>1000 (µg/ml)
260>380320>350
25000

Fusion**IC50 (µM)
0.51.1
2.1 (µg/ml)—* Inhibition effects of chloropeptin I, complestatin, dextran sulfate, and AZT on HIV-1-induced
cytopathic effect (CPE) in MT4 cells. The viability of virus- and mock-infected cells was assessedby the MTT method. Anti-CPE effects are expressed as EC50 values compared with CC50 values ofmock-infected control cells. The selectivity index (SI) was the ratio of IC50 for CPE to CC50.
** Inhibition effects of chloropeptin I, complestatin, and dextran sulfate on HIV-1-induced
syncytia formation in a coculture of virus-infected and uninfected Molt-4 cells. The extent ofcell fusion was assayed. Anti-cell fusion effects are expressed as IC50 values against the fusion ofcontrol cells in the absence of a sample.

4) Antimicrobial activity of chloropeptin I and complestatin assayed by using paper discs
Inhibitory zone (φ mm)				

Test organism

Chloropeptin I
Complestatin
1.00.25 (mg/ml) 1.00.25 (mg/ml)

Staphylococcus aureus FDA 209P
Micrococcus luteus PCI 1001
Bacillus subtilis PCI 219
Acholeplasma laidlawii PG-8 KB 174

11.3
13.8
11.1
12.4*

* hazy zone			

9.8
11.0
9.6
—

11.0
13.1
11.0
11.0*

9.7
10.8
9.4
—
50 µl/8 mm disc

4. References
1. [553] K. Matsuzaki et al., J. Antibiot. 47, 1173-1174 (1994)
2. [649] H. Gouda et al., J. Am. Chem. Soc. 118, 13087-13088 (1996)
3. [652] K. Matsuzaki et al., J. Antibiot. 50, 66-69 (1997)
4. [664] H. Tanaka et al., Nippon Nogei Kagaku Kaishi 71, 530-534 (1997)
5.		
I. Kaneko et al., J. Antibiot. 42, 236-241 (1989)
6.		
H. Seto et al., Tetrahedron Lett. 30, 4987-4990 (1989)
7. [651] H. Tanaka et al., J. Antibiot. 50, 58-65 (1997)
8.		
H. Deng et al., J. Am. Chem. Soc. 125, 9032-9034 (2003)
9.		
S. P. Breazzano & D. L. Boger, J. Am. Chem. Soc. 133, 18495-18502 (2011)10.		
H. Shimamura et al., J. Am. Chem. Soc. 132, 7776-7783 (2010)11.		
Z. Wang et al., Angew. Chem. Int. Ed. 49, 2018-2022 (2010)
12.		
J. Garfunkle et al., J. Am. Chem. Soc. 131, 16036-16038 (2009)