Interesterificación de fosfatidilcolina de yema de huevo y aceites vegetales catalizada por lipasas

The incorporation of polyunsaturated fatty acids into the sn-1 position of egg-yolk phosphatidylcholine (PC) in the process of lipase-catalyzed interesterification was investigated. For this purpose plant oils containing these acids in the triacylglycerol (TAG) form were used as acyl donors and three commercially available immobilized lipases were examined as biocatalysts. In all the experiments the best results were obtained using Novozym 435. After 72 h of the reaction of PC with linseed oil the maximum incorporation of α-linolenic acid into PC was 34%. The result of this reaction was also a reduction in the n-6/n-3 ratio in egg-yolk PC from 24.5 to 0.7. The highest incorporation n-6 PUFAs into PC were obtained with evening primrose oil as the acyl donor, and in this case, 50.7% of n-6 PUFA as the sum of linoleic and γ-linolenic was achieved. The highest content of γ-linolenic acid in modified PC (7.3%) was achieved in the reaction of PC with borage oil.Se ha investigado la incorporación de ácidos grasos poliinsaturados en la posición sn-1 de fosfatidilcolina de yema de huevo (PC) en el proceso de interesterificación catalizado por lipasas. Para lograr este propósito, fueron examinados aceites vegetales que contienen estos ácidos en la forma de triacilgliceroles (TAG) como donadores de acilo y tres lipasas inmovilizadas disponibles comercialmente. En todos los experimentos los mejores resultados se obtuvieron para Novozym 435. La incorporación máxima de ácido α-linolénico en PC fue del 34% después de 72h de la reacción de PC con aceite de linaza. El resultado de esta reacción fue también la reducción de la relación de n-6/n-3 en PC de yema de huevo de 24.5 a 0.7. La incorporación más alta de n-6 PUFAs en PC se logró para el aceite de onagra como donador de acilo, en este caso se alcanzó el 50.7% de n-6 PUFA, como suma de los ácidos linoleico y γ-linolénico. El mayor contenido de ácido γ-linolénico en PC modificado (7.3%) se logró en la reacción de PC con aceite de borraja

Synthesis of γ-lactones with aromatic substituents

Biological activities of lactones are predominantly determined by different substituents on a lactone ring. γ-Lactones with aromatic substituents have interesting biological activities and serve as useful intermediates in the synthesis of many natural and synthetic products. Pulvinic and vulpinic acids exhibit antimicrobial, antioxidant and anticancer activity [1–3]. Paraconic acids have anticancer and antibacterial activity [4, 5]. The interesting biological activities i.a. antileukemic, anti- HIV and cytostatic, have been found for dibenzyl-γ-lactones [8]. This review covers some examples of synthetic and biotechnological methods leading to either racemic or optically active γ-lactones with aromatic substituents. The racemic α-benzylidene lactones can be produced from Baylis-Hillman acetates [9]. The multicomponent synthesis of the paraconic acid analogs is performed by a fourfold metallation-conjugate addition-aldol addition-intramolecular transesterification sequence [4]. Suzuki-Miyaura reaction is the key step in the synthesis of asymmetric pulvinic acids [1]. Some other examples of synthetic strategies involving the reactivity of ylides, vicinal dianions, ozonolysis or Claisen rearrangement are also presented [10–13]. Production of optically active γ-lactones with aromatic substituents involves application of biotechnological and chemical methods. The first one includes using commercially available enzymes [16, 17] or whole cells of microorganisms [18–20]. Chemical methods involve application of chiral starting materials like malic acid esters or the derivatives of succinic acid [14, 15] or chiral catalysts like BINAP-Rh or Ru complexes [7]