This Issue is Dedicated to the Memory of Professor Ivano Morelli

4-Oxo fatty acids Hygrophorus discoxanthus Natural Product Communications Vol. 1 (12) 2006 1083
129.8 (CH, C-3), 131.6 (CH, C-10), 139.7 (CH, C-2),
150.8 (CH, C-6), 170.2 (C, C-1), 188.1 (C, C-4).
Negative ion ESI-FT-ICR-MS: m/z [M – H - ] calcd
for C 18 H 27 O 3 291.1960, found 291.1962.
(2E, 5E)-4-Oxo-hexadeca-2,5,15-trienoic acid (2)
Whitish sticky solid.
Rf : 0.5 (RP18, MeCN-H 2 O, 7:1).
IR (film): 3600-3200, 3050, 2923, 2851, 1690, 1664,
1625, 1279, 1215, 1000, 915 cm -1 .
UV/Vis λ max (CHCl 3 ) nm (log ε): 235 (4.19).
1 H NMR: 1.30-1.65 (12H, brs H 2 -8–H 2 -13), 2.06 (2H,
q, J = 6.8 Hz, H 2 -14), 2.31 (2H, q, J = 7.2 Hz, H 2 -7),
4.95 (1H, dtd, J = 10.3, 1.8, 1.5 Hz, H-16E), 5.02
(1H, dtd, J = 17.0, 1.8, 1.5 Hz, H-16Z), 5.83 (1H, ddt,
J = 17.0, 10.3, 6.7 Hz, H-15), 6.39 (1H, d, J = 15.9
Hz, H-5), 6.75 (1H, d, J = 15.7 Hz, H-3), 7.06 (1H,
dt, J = 15.9, 6.7 Hz, H-6), 7.48 (1H, d, J = 15.7 Hz,
H-2).
13 C NMR: 27.8, 28.7, 28.9, 29.2, 29.3, 29.4 (6 x CH 2 ,
C-8, C-9, C-10, C-11, C-12, C-13), 32.8 (CH 2 , C-7),
33.7 (CH 2 , C-14), 114.0 (CH 2 , C-16), 129.2
(CH, C-5), 129.7 (CH, C-3), 139.0 (CH, C-15), 139.7
(CH, C-2), 151.7 (CH, C-6), 169.5 (C, C-1), 188.2
(C, C-4).
Negative ion ESI-FT-ICR-MS: m/z [M – H - ] calcd
for C 16 H 23 O 3 : 263.1647; found: 263.1649.
(Z)-6-Hydroxy-4-oxo-octadec-11-enoic acid (3)
Whitish sticky solid.
[α] 25 D : -340º (c = 10 mg/mL, CHCl 3 ).
Rf: 0.6 (RP18, MeCN-H 2 O, 7:1).
IR (film): 3600-3200, 3010, 2928, 2856, 1713, 1406,
1260, 1201, 1100 cm -1 .
1 H NMR: 0.88 (3H, t, J = 6.8 Hz, Me), 1.20-1.65
(14H, brs, H 2 -14–H 2 -17, H 2 -7– H 2 -9), 2.05 (4H, q,
J = 7.0 Hz, H 2 -10, H 2 -13), 2.60-2.82 (6H, m, H 2 -2,
H 2 -3, H 2 -5), 4.10 (1H, brm, H-6), 5.25-5.45 (2H, m,
H-11, H-12).
13 C NMR: 14.0 (CH 3 , C-18), 22.5 (CH 2 , C-17), 25.0,
27.0, 27.1, 28.9, 29.5, 29.6 (6 x CH 2 , C-8, C-9,
C-10, C-13, C-14, C-15), 27.4 (CH 2 , C-2), 31.7
(CH 2 , C-16), 36.3 (CH 2 , C-7), 37.5 (CH 2 , C-3), 49.1
(CH 2 , C-5), 67.7 (CH, C-6), 129.3, 130.1 (2 x CH,
C-11, C-12), 177.4 (C, C-1), 209.7 (C, C-4).
Negative ion ESI-FT-ICR-MS: m/z [M – H - ] calcd
for C 18 H 31 O 4 311.2222, found 311.2225.
6-Hydroxy-4-oxo-hexadec-15-enoic acid (4)
Whitish sticky solid.
[α] 25 D : -109º (c = 11 mg/mL, CHCl 3 ).
Rf: 0.7 (RP18, MeCN-H 2 O, 7:1).
IR (film): 3600-3200, 3010, 2917, 2850, 1702, 1412,
1250, 1080, 1000, 913 cm -1 .
1 H NMR: 1.25-1.65 (14H, brs, H 2 -7–H 2 -13), 2.04
(2H, q, J = 6.7 Hz, H 2 -14), 2.60-2.80 (6H, m, H 2 -2,
H 2 -3, H 2 -5), 4.10 (1H, brm, H-6), 4.95 (1H, dtd,
J = 10.3, 1.8, 1.5 Hz, H-16E), 4.99 (1H, dtd, J = 17.0,
1.8, 1.5 Hz, H-16Z), 5.83 (1H, ddt, J = 17.0, 10.3,
6.7 Hz, H-15).
13 C NMR: 27.4 (CH 2 , C-2), 25.3, 28.8, 29.0, 29.2,
29.3, 29.4 (6 x CH 2 C-8, C-9, C-10, C-11, C-12,
C-13), 33.7 (CH 2 , C-14), 36.3 (CH 2 , C-7), 37.6
(CH 2 , C-3), 49.1 (CH 2 , C-5), 67.8 (CH, C-6), 114.0
(CH 2 , C-16), 139.1 (CH, C-15), 177.1 (C, C-1), 209.7
(C, C-4).
Negative ion ESI-FT-ICR-MS: m/z [M – H - ] calcd
for C 16 H 27 O 4 283.1909, found 283.1911.
6-Hydroxy-4-oxo-hexadecanoic acid (5)
Whitish sticky solid.
[α] 25 D : -95º (c = 10 mg/mL, CHCl 3 ).
Rf: 0.65 (RP18, MeCN-H 2 O, 7:1).
IR (film): 3600-3200, 2920, 2855, 1710, 1415,
1255 cm -1 .
1 H NMR: 0.88 (3H, t, J = 6.8 Hz, Me), 1.20-1.60
(18H, brs, H 2 -7–H 2 -15), 2.60-2.80 (6H, m, H 2 -2,
H 2 -3, H 2 -5), 4.10 (1H, brm, H-6).
13 C NMR: 14.0 (CH 3 , C-16), 27.6 (CH 2 , C-2),
22.8-29.6 (8 x CH 2 , C-8, C-9, C-10, C-11, C-12,
C-13, C-14, C-15), 36.3 (CH 2 , C-7), 37.6 (CH 2 , C-3),
49.1 (CH 2 , C-5), 67.7 (CH, C-6), 177.2 (C, C-1),
209.5 (C, C-4).
Negative ion ESI-FT-ICR-MS: m/z [M – H - ] calcd
for C 16 H 29 O 4 285.2066, found 285.2064.
Ozonolysis of acid 3: A saturated solution of O 3 in
CH 2 Cl 2 -MeOH, 4:1 v/v, was added to compound 3
(3 mg) dissolved in CH 2 Cl 2 , (0.5 mL) at –78°C. The
reaction was quenched after 3 h by adding excess
Me 2 S and the mixture was left at –20°C overnight. A
sample was directly analyzed by GC under the
following conditions: column HP-5 (25 m×0.25 mm,
0.33 μm film thickness), injection temperature
250°C, detector (FID) temperature 280°C, carrier gas
nitrogen, flow rate 1.27 mL/min, constant flow mode,
split splitless injection, ratio 1:35, column
temperature program: 40°C for 5 min, then raised to
100°C at a rate of 2°C/min, then raised to 280°C at a
rate of 10°C/min, then isothermal at 280°C for 5 min.
Enrichment of the peak eluted at 9.69 min with an
authentic sample of heptanal, confirmed its identity.
Fungicidal activity: A simple test, adapted from the
literature [4a, 12], was carried out to reveal the