Optimizing the Synthesis Strategy of the Chlorinated Chain Characteristic to the Enacyloxin Series Using Models.

In this paper are presented the results of the preliminary studies conducted on two model substrates that allowed the testing of various strategies and set the proper conditions that thereafter culminated in the synthesis of the C1-C23 chain of enacyloxin-IIa and its congeners. Innovative strategic options were explored on each model allowing the stereochemical control of the following two elements: (a) the 2, 4, 6, 8, and 10 chlorinated undecapentaenoic chain, thanks to -selective Kaneda's alkyne allylchlorination and an -selective Pd/Cu allene-alkyne coupling and (b) the unusual - -OH/-Cl/-OCONH 17-19 triad, thanks to a highly diastereoselective Mukaiyama aldol reaction.

Advancements in Enacyloxins Total Synthesis: Access to the Chlorinated Polyunsaturated Chain Peculiar to this Promising Family of Antibiotics.

The first synthesis of the protected chain specific to the enacyloxin antibiotic family is reported. The noticeable features are (a) the construction of the chlorinated undecapentaenoic moiety implementing the sequence Tsuji's alkyne allyl-chlorination, -selective Pd/Cu-catalyzed allene-alkyne coupling, Horner-Wadsworth-Emmons olefination, dehydration; (b) control of the C18 chlorinated stereogenic center by organo-catalyzed aldehyde α-chlorination; and (c) the assemblage of this aldehyde with the C1-C16 ketone using a highly diastereoselective Mukaiyama aldol.

Identification of new Omega-3 very long chain poly-unsaturated fatty acids in meibomian gland secretions.

Three new very long chain polyunsaturated fatty acids (VLC PUFA) belonging to the omega-3 family have been identified in meibum samples collected by Schirmer strips. These VLC PUFA, namely FA (32:3), FA (34:3) and FA (36:3), were detected in O-acyl-ω-hydroxy fatty acids using a molecular network approach, and as free fatty acids. Identification was supported by retention time prediction model, exact mass determination and isotopic patterns.