E. Takanashi et al. / Tetrahedron 71 (2015) 9564e9570
9569
acanthomicroxea, and microrhabds are much larger in P. menoui,
3.8. Yakushynol E (5)
and crepis of the megaclone is longer in the present specimen.
Furthermore, geographical distribution of the both species is dis-
tant: P. menoui has been reported only from deep sea of the
southern hemisphere such as Lord Howe and Norfolk Islands, New
Caledonia and New Zealand.30,31 Hence here we tentatively regard
our specimen as different species from P. menoui. The specimen
used for the identification (NSMT-Po-2482) is deposited at Na-
tional Museum of Nature and Science, Tokyo.
Pale yellow oil; [
a
]
19 þ41 (c 0.06, MeOH); UV (MeOH) lmax (log
3
D
194 (3.45); (CD3OD, 600 MHz): 5.86 (H-5, H-29), 5.73 (H-4, H-30),
4.81 (H-3, H-31), 4.06 (H-6, H-28), 2.89 (H-1, H-33), 1.50 (H-7, H-
27), 1.37 (H-14), 1.2e1.4 (H-8 to H-12, H-16 to H-26), 1.29 (H-13 and
H-15), 1.08 (H-13 and H-15), 0.85 (14-Me); 13C NMR (CD3OD,
150 MHz): 136.2 (C-5, C-28), 130.3 (C-4, C-29), 84.3 (C-2, C-31), 74.6
(C-1, C-32), 72.4 (C-6, C-27), 62.5 (C-3, C-30), 38.1 (C-7, C-26), 37.9
(C-13, C-15), 33.6 (C-14), 30.5 (C-8 to C-11, C-17 to C-26), 27.0 (C-12,
C-16), 26.3 (C-8, C-25), 20.0 (14-Me); HRESIMS m/z 539.4054
[MþNa]þ (calcd for C33H56O4Na, 539.4076).
3.3. Extraction and isolation
The sponge specimen was frozen after collection and kept fro-
zen until extraction. The sample (1 kg) was extracted with MeOH
(2ꢂ3 L) and CHCl3/MeOH (1:1) (1ꢂ3 L). The extracts were com-
bined, evaporated, and partitioned between H2O and CHCl3
(3ꢂ500 mL). The CHCl3 fraction was further partitioned between
90% MeOH and n-hexane. The aqueous MeOH fraction was sepa-
rated by ODS flash chromatography with aq MeOH and
CHCl3eMeOH (1:1) to afford six fractions. An active fraction was
separated by reversed-phase HPLC (Cosmosil MS-II, 20ꢂ250 mm)
with 70e100% MeOH to afford yakushynol B (2, 1.6 mg), C (3,
8.7 mg), and D (4, 4.8 mg). Another active fraction was purified by
reversed-phase HPLC (COSMOSIL AR-II, 10ꢂ250 mm) with 80%
MeOH to give yakushynol A (1, 1.6 mg), E (5, 1.4 mg), neo-
petroformyne E (7, 0.4 mg), and yakushynol F (6, 0.6 mg).
3.9. Yakushynol F (6)
Pale yellow oil; [
a
]
22 þ43 (c 0.03, MeOH); UV (MeOH) lmax (log
3
D
222 (3.39), 215 (3.38), 204 (3.49); 1H NMR (CD3OD, 600 MHz) and
13C NMR (CD3OD) data, see Table 2; HRESIMS m/z 461.3348
[MþNa]þ (calcd for C30H46O2Na, 461.3396).
3.10. Neopetroformyne E (7)
Pale yellow oil; [
a
]
21 þ150 (c 0.02, MeOH); UV (MeOH) lmax (log
D
3
3.4. Yakushynol A (1)
3.11. Preparation of MTPA esters
Pale yellow oil; [
a
]
21 þ11 (c 0.07, MeOH); UV (MeOH) lmax (log
)
To a solution of the compound (1: 0.1 mg, 3: 80
0.1 mg, 7: 50 g) in dry pyridine (10 L) was added (R)-MTPACl
(2 L). The solutions were left at room temperature for 24 h, and the
reaction mixtures were diluted with H2O and extracted with CHCl3.
The organic layers were purified by reversed-phase HPLC to afford
the (S)-MTPA esters. (R)-MTPA esters of compound 1, 2, and 5 were
prepared in a similar way using (S)-MTPACl.
mg, 4: 0.1 mg, 5:
D
m
m
m
3.5. Yakushynol B (2)
Pale yellow oil; [
a
]
22 þ55 (c 0.08, MeOH); UV (MeOH) lmax (log
3
D
208 (3.68); 1H NMR (CD3OD, 600 MHz): 5.86 (H-5, H-29), 5.73 (H-4,
H-30), 5.34 (H-15, H-16), 4.81 (H-3, H-31), 4.06 (H-6, H-28), 2.89
(H-1, H-33), 2.03 (H-14, H-17), 1.50 (H-7, H-27), 1.2e1.4 (H-8 to H-
13, H-18 to H-26); 13C NMR (CD3OD, 150 MHz): 136.2 (C-5, C-29),
130.7 (C-15, C-16), 130.3 (C-4, C30), 84.3 (C-2, C-32), 74.6 (C-1, C-
33), 72.4 (C-6, C-28), 62.5 (C-3, C-31), 38.1 (C-7, C-27), 30.5 (C-9 to
C-13, C-18 to C-25), 27.9 (C-14, C-17), 26.3 (C-8, C-26); HRESIMS m/z
537.3893 [MþNa]þ (calcd for C33H54O4Na, 537.3920).
3.12. Tetra-(S)-MTPA ester of 1 (1a)
(CD3OD, 600 MHz) d 7.45, 7.39, 7.38, 6.09 (H-3, H-32), 5.88 (H-5,
H-30), 5.69 (H-4, H-31), 5.45 (H-6, H-29), 5.33 (H-15, H-16), 3.50
(OMe), 2.65 (H-1, H-34), 2.02 (H-14, H-17), 1.68 (H-7, H-28), 1.62 (H-
7, H-28), 1.2e1.4; ESIMS m/z 1415 [MþNa]þ.
3.13. Tetra-(R)-MTPA ester of 1 (1b)
1H NMR (CD3OD, 600 MHz)
d 7.48, 7.40, 7.40, 6.13 (H-3, H-32),
3.6. Yakushynol C (3)
6.11 (H-5, H-30), 5.95 (H-4, H-31), 5.52 (H-6, H-29), 5.34 (H-15, H-
16), 3.48 (OMe), 2.65 (H-1, H34), 2.02 (H-14, H-17), 1.63 (H-7, H-28),
1.61 (H-7, H-28), 1.2e1.4.; ESIMS m/z 1415 [MþNa]þ.
Pale yellow oil; [
a
]
22 ꢀ65 (c 0.23, MeOH); UV (MeOH) lmax (log
3
D
206 (3.67); 1H NMR (CD3OD, 600 MHz): 5.86 (H-5, H-28), 5.73 (H-4,
H-29), 5.34 (H-15, H-16), 4.81 (H-3, H-30), 4.06 (H-6, H-27), 2.89
(H-1, H-32), 2.03 (H-14, H-17), 1.50 (H-7, H-26), 1.2e1.4 (H-8 to H-
13, H-18 to H-25); 13C NMR (CD3OD, 150 MHz) 136.2 (C-5, C-28),
130.7 (C-15, C-16), 130.3 (C-4, C-29), 84.3 (C-2, C-31), 74.6 (C-1, C-
32), 72.4 (C-6, C-27), 62.5 (C-3, C-30), 38.1 (C-7, C-26), 30.5 (C-9 to
C-13, C-18 to C-24), 27.9 (C-14, C-17), 26.3 (C-8, C-25); HRESIMS m/z
523.3737 [MþNa]þ (calcd for C32H52O4Na, 523.3763).
3.14. Tetra-(R)-MTPA ester of 2 (2b)
(CD3OD, 600 MHz) d 7.45, 7.39, 7.38, 6.09 (H-3, H-31), 5.88 (H-5,
H-29), 5.69 (H-4, H-30), 5.45 (H-6, H-28), 5.33 (H-15, H-16), 3.50
(OMe), 2.65 (H-1, H-33), 2.02 (H-14, H-17), 1.68 (H-7, H-27), 1.62 (H-
7, H-27), 1.2e1.4; ESIMS m/z 1401 [MþNa]þ.
3.7. Yakushynol D (4)
3.15. Tetra-(S)-MTPA ester of 3 (3a)
Pale yellow oil; [
a
]
22 ꢀ49 (c 0.15, MeOH); UV (MeOH) lmax (log
)
(CD3OD, 600 MHz) d 7.45, 7.39, 7.38, 6.09 (H-3, H-30), 5.88 (H-5,
D
H-28), 5.69 (H-4, H-29), 5.45 (H-6, H-27), 5.33 (H-15, H-16), 3.50
(OMe), 2.65 (H-1, H-32), 2.02 (H-14, H-17), 1.68 (H-7, H-26), 1.62 (H-
7, H-26), 1.2e1.4; ESIMS m/z 1387 [MþNa]þ