Macrosphelide ©

1. Discovery, producing organism and structures
Macrosphelides A-D, J and K were isolated from the culture broth of Paraconiothyrium sporulosum FO-5050 and recognized as cell-adhesion inhibitors1-6). It was reported by Numata et althat macrosphelides E-I, L were isolated from another fungal strain7-9). Recently, the structure ofmacrosphelide D was revised and determined by using NMR spectroscopy and by synthesizing
its stereoisomers in Curran’s group.11)

pycnidium
Bar: 100 µm

conidia
Bar: 20 µm

Microsphaeropsis sp. FO-5050(Paraconiothyrium sporulosum FO-5050)

2. Physical data (Macrosphelide A)1-5)
Colorless needles.C16H22O8 ; mol wt 342.13. Sol. in CHCl3, MeOH, EtOAc. Insol. in hexane.
3. Biological activity
1) Inhibition of cell adhesion1,3)Macrosphelide (MS) A showed potent inhibitory activity against cell adhesion of human leukemia cell (HL-60) to LPS-activated human umbilical vein endothelial cell (HUVEC), with an
IC50 value of 3.5 µM. The IC50 values of macrosphelides B, C and D were 36, 67.5 and 25 µM,
respectively. The IC50 values of both macrosphelides J and K were greater than 100 µg/ml. Macrosphelide A and B did not show any cytocidal activities at a concentration of 100 µg/ml.

120
Cell adhesion (%)

100
MS-AMS-B
MS-CMS-D

80
6040200.1

1
10100
Concentration ( M )10002) MSB suppressed metastasis through inhibition of adhesion of sLex/E-selectin molecules9).
MSB inhibits adhesion of sialyl Lewisx (sLe x)-expressing HL-60 cells to LSP-activated(E-selectin-expressing) HUVECs in vitro. When MSB was administered to B16/BL6 mice at20 mg/kg/day, lung metastatic nodules of B16/BL6 mouse melanoma cells (B16/BL6 cells)
were significantly decreased (T/C = 45%). Flow cytometry analysis showed that B16/BL6 cells
expressed high levels of sLex antigens. Under in vitro conditions, B16/BL6 cells demonstrated agreater degree of adhesion to LSP-activated HUVECs, but adhesion was significantly inhibitedby MSB and sLe x antibodies. Combined therapy of MSB and cisplatin (CDDP) induced
remarkable lung metastasis inhibition without the adverse effects of CDDP to the host.

201008015***604010520051020MSB (mg/kg/day)

0Number ofmetastatic nodules

120014025Body weight (g)Lung metastasis (%)

1401201008060402000CDDPMSB(mg/kg/day)

3 100031053) Macrosphelide A inhibited growth of some ascomycetes, basidiomycetes, oomycetes andGram-positive bacteria. Minimum inhibitory concentration of this compound against Staphylococcus aureus was <500 μg/ml. No inhibitory activities were observed against yeasts andGram-negative bacteria at 700 mg/μl of macrosphelide A.12)
4. Total synthesis4,5)
The total syntheses of macrosphelides have been reported by several groups. The following
scheme is Ōmura’s approach (See Appendix-I).

O

Ot-Bu 2) TBSCl 78%

H 3C

OTBS
H 3C

O

H 3C

1) AD-mix-α 71%

OMEM

OO

H 3C

Ot-Bu
0.2N NaOH
96%

OMEM
CH 3O
OMEM
O HO OH
CH 3

H 3C

ClCOClCl, Et 3N,

DMAP 91%

Ot-Bu

OMEM
O

OMEM

ClO

H 3C

Ot-Bu

OTBS

1) PPh 3, DEAD,
HCOOH
2) dil. NH 3
83% for 2 steps

H 3COOTBS
H 3COOH

OH

TBAF
100%O

OTBS

OOH

O
CH 3TFA

OOOH

CH 3OH
OOO

MEMCl
100%OHO

1) TBSO
DCC, DMAP, CSA
96%2) TFA•thioanosole
64%

OH

O

90%
H 3C

OMEM
CH 3
OMEM
t-BuO

H 3C

OMEM
CH 3
OMEM
O O

O

2) TFA•THF•H2O
99%

Ot-Bu

OHOO

1) DCC, DMAP, CSA
86%

O

O
CH 3

Macrosphelide A
Overall yield 20% in 11 steps

5. References
1. [597] M. Hayashi et al., J. Antibiot. 48, 1435-1439 (1995)
2. [602] S. Takamatsu et al., J. Antibiot. 49, 95-98 (1996)
3. [683] S. Takamatsu et al., J. Antibiot. 50, 878-880 (1997)
4. [680] T. Sunazuka et al., J. Am. Chem. Soc. 119, 10247-10248 (1997)
5. [885] T. Sunazuka et al., Tetrahedron 61, 3789-3803 (2005)
6. [831] A. Fukami et al., J. Antibiot. 52, 501-504 (1999)
7.			
A. Numata et al., Tetrahedron Lette. 38, 8215-8218 (1997)
8.			
A. Numata et al., J.Chem. Soc., Perkin Trans. I 3046-3053 (2001)
9.		
A. Numata et al., J. Antibiot. 55, 147-154 (2002)
10. [801] A. Fukami et al., Bioche. Biophys. Res. Comm. 291, 1065-1070 (2002)
11. 		
D. P. Curran et al., Nat. Chem. 4, 124-129 (2012)12.		
N. Tomprefa et al., J. Appl. Microbiol. 106, 2048-2056 (2009)