Enzymatic synthesis of a bicyclobutane fatty acid by a hemoprotein–lipoxygenase fusion protein from the cyanobacterium Anabaena PCC 7120

Fig. 3.

Configuration of the bicyclobutane ring of product 1. The NOESY NMR spectrum of product 1 was recorded in d6-benzene at 600 MHz. The partial chemical structure illustrates the through-space couplings of the single protons at H13 and H16, the two ends of the bicyclobutyl ring. The 13-exo,16-endo configuration of the ring can be deduced from the observation that the coupling of H13 to H14/15 is weak, whereas H16-H14/15 is strong, and that the coupling of H13 to H17 is strong, whereas there is no detectable NOE between H12 and H16 (SI Fig. 9). 

Data Set 1
Shown here are the NMR chemical shift and multiplicities data on product 1.
NMR data on C18.3w3 Anabaena product 1 methyl ester, 600 MHz, d6-benzene at 7.16 ppm.

d 5.39, dd, J_11,12 = 15.5 Hz, J_12,13 = 8.2 Hz, 1H, H12; d 5.34, dd, J_10,11 = 7.1 Hz, J_11,12 = 15.4 Hz, 1H, H11; d3.36, s, 3H, OCH₃; d 2.94, dd, J_9,10 = 2.0 Hz, J_10,11 = 7.1 Hz, 1H, H10; d 2.64, dt, J_8,9 = 5.6 Hz, J_9,10 = 2.0 Hz, 1H, H9; d 2.36, d, J_12,13 = 8.2 Hz, 1H, H13; d 2.10, t, J_2,3 = 7.4 Hz, 2H, H2; d 1.91, m, J = 3.6 Hz, 1H, H16; d 1.53, q, J = 7.4 Hz, 2H, H3; d 1.37, m, 2H, H8; d 1.31 and 1.34, two dd, J_(14,15) »11 Hz, J_(14,16) »3 Hz, 2H, H14, H15^†; d 1.29-1.35, m, H7a; d 1.20-1.28, m, 1H, H7b; d 1.16, q, J_16,17 = J_17,18 = 7.3 Hz, 2H, H17; d 1.06-1.16, m, 6H, H4, H5, H6; d 0.87, t, J_17,18 = 7.4 Hz, 3H, H18.
^†The two dd signals represent H14 and H15, although they are not individually assigned.




Data Set 2
Shown here are the NMR chemical shift and multiplicities data on product 2.
¹H-NMR on product 2 methyl ester, the C18.3w3 LTA-type epoxide, 9R,10R-trans-epoxyoctadeca-11E,13E,15Z-trienoic acid. 600 MHz, d6-benzene at 7.16 ppm.

d 6.51, dd, J_14,15 = 11.8 Hz, J_13,14 = 14.6 Hz, 1H, H14; d 6.40, dd, J_12,13 = 10.9 Hz, J_11,12 = 15.2 Hz, 1H, H12; d 6.14, dd, J_12,13 = 11.1 Hz, J_13,14 = 14.8 Hz, 1H, H13; d 6.03, t, J_14,15 = J_15,16 = 11.0 Hz, 1H, H15; d 5.42, m, 1H, H16; d 5.39, m, 1H, H11; d 3.53, s, 3H, OCH₃; d 3.02, br d, J_10,11 = 7.9 Hz, J_9,10 ~1 Hz, 1H, H10; d 2.67, br t, J_8,9 = 4.6 Hz, J_9,10 ~1 Hz, 1H, H9; d 2.10, t, J = 7.4 Hz, 2H, H2; d 2.06, q, J = 7.6, 2H, H17; d 1.53, q, 2H, H3, d 1.35-1.43, m, 2H, H8; d 1.28-1.35, m, 1H, H7a; d 1.21-1.28, m, 1H, H7b; d 1.06-1.16, m, 6H, H4, H5, H6; d 0.88, t, J_17,18 = 7.6, 3H, H18.

 http://www.pnas.org/content/104/48/18941/F3.expansion.html
 http://www.pnas.org/content/suppl/2007/12/18/0707148104.DC1#F5