US 12,331,015 B2
Highly unsaturated fatty acid or highly unsaturated fatty acid ethyl ester with reduced environmental pollutants, and method for producing same
Nobushige Doisaki, Tokyo (JP); Kazuhiko Hata, Ibaraki (JP); Shinji Tokiwa, Ibaraki (JP); and Kazunori Matsushima, Tokyo (JP)
Assigned to NISSUI CORPORATION, Tokyo (JP)
Filed by NIPPON SUISAN KAISHA, LTD., Tokyo (JP)
Filed on Feb. 6, 2023, as Appl. No. 18/164,765.
Application 15/366,522 is a division of application No. 14/400,652, granted, now 9,540,306, issued on Jan. 10, 2017, previously published as PCT/JP2013/063425, filed on May 14, 2013.
Application 18/164,765 is a continuation of application No. 17/317,179, filed on May 11, 2021, granted, now 11,603,347.
Application 17/317,179 is a continuation of application No. 16/514,191, filed on Jul. 17, 2019, granted, now 11,034,643, issued on Jun. 15, 2021.
Application 16/514,191 is a continuation of application No. 15/366,522, filed on Dec. 1, 2016, granted, now 10,399,922, issued on Sep. 3, 2019.
Claims priority of application No. 2012-110809 (JP), filed on May 14, 2012.
Prior Publication US 2023/0183165 A1, Jun. 15, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C07C 51/44 (2006.01); B01D 3/14 (2006.01); C07C 51/47 (2006.01); C07C 57/03 (2006.01); C07C 67/03 (2006.01); C07C 67/54 (2006.01); C07C 67/56 (2006.01); C07C 69/587 (2006.01); C11B 3/12 (2006.01); C11C 1/04 (2006.01); C11C 3/00 (2006.01); A23D 9/02 (2006.01); A23L 33/115 (2016.01); A61K 31/20 (2006.01); A61K 31/202 (2006.01); A61K 31/232 (2006.01); B01D 15/32 (2006.01); C11B 3/16 (2006.01)
CPC C07C 51/44 (2013.01) [B01D 3/143 (2013.01); C07C 51/47 (2013.01); C07C 57/03 (2013.01); C07C 67/03 (2013.01); C07C 67/54 (2013.01); C07C 67/56 (2013.01); C07C 69/587 (2013.01); C11B 3/12 (2013.01); C11C 1/04 (2013.01); C11C 3/003 (2013.01); A23D 9/02 (2013.01); A23L 33/115 (2016.08); A61K 31/20 (2013.01); A61K 31/202 (2013.01); A61K 31/232 (2013.01); B01D 15/325 (2013.01); C11B 3/16 (2013.01)] 14 Claims
 
1. A method of producing a highly unsaturated fatty acid ethyl ester with reduced contents of polychlorinated dibenzoparadioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar PCB (Co-PCBs), the method comprising the steps of:
a) removing free fatty acids and environmental pollutants by thin-film distillation from a feedstock oil derived from a marine product, the feedstock oil containing highly unsaturated fatty acids as constituent fatty acids, and the highly unsaturated fatty acids containing at least 18 carbon atoms and at least 3 double bonds;
b) ethyl esterifying the highly unsaturated fatty acids present as constituent of fat or oil contained in the product of step (a);
c) refining the product of step (b) by rectification and column chromatography, wherein a concentration of the highly unsaturated fatty acid ethyl ester in the sum of fatty acid ethyl esters is at least 80area %.