Search

Glycidyl fatty acid esters (GEs) are processing contaminants formed during refining steps of vegetable oils. 'In vivo' hydrolysis of GEs releases potentially carcinogenic and genotoxic glycidol (2,3-epoxy-1-propanol). Occurrence of GEs in vegetable oils used for infant formula manufacturing may pose a potential health concern for formula-fed infants. Refined oils are commonly used as the main fat ingredient in formula manufacturing. For this study, different infant formula products (powders, concentrates and ready-to-feed formula products) were purchased and analysed in 2015 (35 samples) and 2019 (33 samples). Seven individual GEs were analysed by LC-MS/MS via direct approach by stable isotope dilution analysis, and total bound glycidol concentrations were calculated. Concentrations of bound glycidol in reconstituted formula reached maxima of 40.3 ng/g in the 2015 samples and 31.5 ng/g in the samples collected in 2019, with respective means of 8.7 ng/g and 6.7 ng/g. The analysed bound glycidol concentrations are comparable with concentration ranges from other studies, but are higher than observed in studies from the European market. Temporal trend data show a reduction of bound glycidol concentrations in 2019. GE concentrations were compared across different manufacturers. [ABSTRACT FROM AUTHOR]

Reaction of (p-tol3P)2PtCl2 and Me3Sn(C≡C)2SiMe3 (1 : 1/THF/reflux) gives monosubstituted trans-Cl(p-tol3P)2Pt(C≡C)2SiMe3 (63%), which with wet n-Bu4N+ F− yields trans-Cl(p-tol3P)2Pt(C≡C)2H (2, 96%). Hay oxidative homocoupling (O2/CuCl/TMEDA) gives all-trans-Cl(p-tol3P)2Pt(C≡C)4Pt(Pp-tol3)2Cl (3, 68%). Reaction of 3 and Me3Sn(C≡C)2SiMe3 (1 : 1/rt) affords monosubstituted all-trans-Cl(p-tol3P)2Pt(C≡C)4Pt(Pp-tol3)2(C≡C)2SiMe3 (46%), which is converted by a similar desilylation/homocoupling sequence to all-trans-Cl[(p-tol3P)2Pt(C≡C)4]3Pt(Pp-tol3)2Cl (7; 79%). Reaction of (p-tol3P)2PtCl2 and excess H(C≡C)2SiMe3 (HNEt2/cat. CuI) gives trans-Me3Si(C≡C)2Pt(Pp-tol3)2(C≡C)2SiMe3 (78%), which with wet n-Bu4N+ F− affords trans-H(C≡C)2Pt(Pp-tol3)2(C≡C)2H (96%). Hay oxidative cross coupling with 2 (1 : 4) gives all-trans-Cl[(p-tol3P)2Pt(C≡C)4]2Pt(Pp-tol3)2Cl (10, 36%) along with homocoupling product 3 (33%). Reaction of 3 and Me3Sn(C≡C)2SiMe3 (1 : 2/rt) yields all-trans-Me3Si(C≡C)2(p-tol3P)2Pt(C≡C)4Pt(Pp-tol3)2(C≡C)2SiMe3 (17, 77%), which with wet n-Bu4N+ F− gives all-trans-H(C≡C)2(p-tol3P)2Pt(C≡C)4Pt(Pp-tol3)2(C≡C)2H (96%). Reaction of 3 and excess Me3P gives all-trans-Cl(Me3P)2Pt(C≡C)4Pt(PMe3)2Cl (4, 86%). A model reaction of trans-(p-tol)(p-tol3P)2PtCl and KSAc yields trans-(p-tol)(p-tol3P)2PtSAc (12, 75%). Similar reactions of 3, 7, 10, and 4 give all-trans-AcS[(R3P)2Pt(C≡C)4]nPt(PR3)2SAc (76–91%). The crystal structures of 3, 17, and 12 are determined. The first exhibits a chlorine–chlorine distance of 17.42 Å; those in 10 and 7 are estimated as 30.3 Å and 43.1 Å. [ABSTRACT FROM AUTHOR]

Reaction of (p-tol3P)2PtCl2 and Me3Sn(C[triple bond, length as m-dash]C)2SiMe3 (1 : 1/THF/reflux) gives monosubstituted trans-Cl(p-tol3P)2Pt(C[triple bond, length as m-dash]C)2SiMe3 (63%), which with wet n-Bu4N+ F- yields trans-Cl(p-tol3P)2Pt(C[triple bond, length as m-dash]C)2H (2, 96%). Hay oxidative homocoupling (O2/CuCl/TMEDA) gives all-trans-Cl(p-tol3P)2Pt(C[triple bond, length as m-dash]C)4Pt(Pp-tol3)2Cl (3, 68%). Reaction of 3 and Me3Sn(C[triple bond, length as m-dash]C)2SiMe3 (1 : 1/rt) affords monosubstituted all-trans-Cl(p-tol3P)2Pt(C[triple bond, length as m-dash]C)4Pt(Pp-tol3)2(C[triple bond, length as m-dash]C)2SiMe3 (46%), which is converted by a similar desilylation/homocoupling sequence to all-trans-Cl[(p-tol3P)2Pt(C[triple bond, length as m-dash]C)4]3Pt(Pp-tol3)2Cl (7; 79%). Reaction of (p-tol3P)2PtCl2 and excess H(C[triple bond, length as m-dash]C)2SiMe3 (HNEt2/cat. CuI) gives trans-Me3Si(C[triple bond, length as m-dash]C)2Pt(Pp-tol3)2(C[triple bond, length as m-dash]C)2SiMe3 (78%), which with wet n-Bu4N+ F- affords trans-H(C[triple bond, length as m-dash]C)2Pt(Pp-tol3)2(C[triple bond, length as m-dash]C)2H (96%). Hay oxidative cross coupling with 2 (1 : 4) gives all-trans-Cl[(p-tol3P)2Pt(C[triple bond, length as m-dash]C)4]2Pt(Pp-tol3)2Cl (10, 36%) along with homocoupling product 3 (33%). Reaction of 3 and Me3Sn(C[triple bond, length as m-dash]C)2SiMe3 (1 : 2/rt) yields all-trans-Me3Si(C[triple bond, length as m-dash]C)2(p-tol3P)2Pt(C[triple bond, length as m-dash]C)4Pt(Pp-tol3)2(C[triple bond, length as m-dash]C)2SiMe3 (17, 77%), which with wet n-Bu4N+ F- gives all-trans-H(C[triple bond, length as m-dash]C)2(p-tol3P)2Pt(C[triple bond, length as m-dash]C)4Pt(Pp-tol3)2(C[triple bond, length as m-dash]C)2H (96%). Reaction of 3 and excess Me3P gives all-trans-Cl(Me3P)2Pt(C[triple bond, length as m-dash]C)4Pt(PMe3)2Cl (4, 86%). A model reaction of trans-(p-tol)(p-tol3P)2PtCl and KSAc yields trans-(p-tol)(p-tol3P)2PtSAc (12, 75%). Similar reactions of 3, 7, 10, and 4 give all-trans-AcS[(R3P)2Pt(C[triple bond, length as m-dash]C)4]nPt(PR3)2SAc (76-91%). The crystal structures of 3, 17, and 12 are determined. The first exhibits a chlorine-chlorine distance of 17.42 Å; those in 10 and 7 are estimated as 30.3 Å and 43.1 Å.