Partial purification ofNigella sativaL. Seed lipase and its application in transesterification reactions

Abstract

Nigella sativa L. seed lipase isolated from defatted seeds was partially purified and used as catalyst in transesterification reactions. Purification of an ammonium sulfate-precipitated sample (at 35% saturation, Nigella PL) by DEAE ion-exchange chromatography increased the specific activity from 13.9 to 156.7 U/mg protein. Nigella PL and Nigella CPL (the partially purified enzyme sample obtained by DEAE ion-exchange chromatography) catalyzed the transesterification of vinyl acetate with octanol, with racemic sulcatol (6-methyl-5-hepten-2-ol), and with racemic trans-sobrerol (trans-p-menth-6-ene-2,8-diol) in different organic solvents. Both activity and enantioselectivity of the enzyme samples used for these biotransformations were affected by the nature of the organic solvent.Lipases, which catalyze not only the hydrolysis of TAG but also their synthesis from glycerol and FFA, can be used in the production of detergents, foods, pharmaceuticals, and other synthetic organic materials (1).Lipases can be obtained from mammals, yeast, bacteria, and higher plants. To date, most industrial lipases have been produced from fungal sources. These enzymes are usually well characterized, but lipases from higher plants generally have not yet been investigated in detail despite the fact that they may display different properties that could be exploited for industrial or technical purposes. Lipases are present in oil seeds, such as rape (Brassica napus), mustard (Sinapis alba), and cereals (2,3). Usually these enzymes are absent in dormant seed and are produced during seed germination. However, Nigella sativa L, also known as black cumin or fennel flower, contains active lipases even in its dormant seeds (3-5).FA selectivity of lipases has been utilized to enrich for FA (or of their derivatives) from naturally occurring mixtures (6). More recently, lipases have been used as biocatalysts for the enzymatic resolution of racemic substances to produce pure enantiomeric drugs (7,8).Nigella sativa L. is a member of the Ranunculaceae family (9). Its capsule-shaped fruit contains the black-colored, oval, and three-faced seeds. Owing to their aromatic nature, Nigella sativa L. seeds are used as condiment or spice in cooking.Crude and immobilized N. sativa L. lipases are effective biocatalysts for the hydrolysis and glycerolysis of TAG and for the esterification of FFA (5,10-12). A crude lipase sample from N. sativa L. seeds was immobilized by adsorption on Celite 535 from phosphate buffer solutions at pH values varying from 5.0 to 8.0 at 25°C, and pH 6 was established to be optimal for adsorption (12).The goals of this study were to obtain crude and partially purified samples of lipase(s) and to investigate the efficiency of these enzymatic preparations for transesterification reactions in organic solvents. EXPERIMENTAL PROCEDURESMaterials. Nigella sativa L. seeds from the Denizli region of Turkey were purchased locally. The proximate compositions of the seeds, determined according to standard AOCS methods (13), were 9.4% moisture, 4% a...

Seed lipases: sources, applications and properties - a review

“…Seed lipases present certain advantages since they do not necessarily have to be purified in order to perform this and other processes (Caro et al, 2000). A partially purified raw extract of Nigella sativa L. was used by Tuter et al (2003) as a lipase source for enriching borage oil with gamma-linolenic fatty acid, obtaining 34.6% incorporation. Thus, this review will cover studies involving seed lipases, including their possible industrial applications according to their individual features.…”

“…The Nigella sativa seed lipase was also studied by Tuter et al (2003). The seed lipases were partially purified and then applied in transesterification and esterification reactions in the presence of different organic solvents.…”

“…Their usage reduces expenses with energy and minimizes the heat degradation of compounds in comparison to traditional chemical processes (Freire and Castilho, 2008). Tuter et al (2003) used Nigella sativia L. seed lipases to enrich borage oil with gamma-linolenic acid. The best result was obtained in an experiment carried out with 330 U/g of semi-purified freezedried seed extract and 200 U/g of freeze-dried seed and oil.…”

Plant lipases and their applications in oils and fats modification

“…For example, Dandik and Aksoy did an extensive study of this lipase in oleochemical reactions [22]. They [23]. The lipase was isolated from defatted seeds and then purification was carried out by DEAE ion-exchange chromatography allowing an increase of its lipolytic activity from 13.9 to 156.7 U/mg protein.…”

Enzymatic resolution of racemic sulcatol by lipase from Candida Antarctica in a large scale

“…(E = 27-29) [8], lipase Amano PS (E = 11-38) [9][10], lipase PPL from Pseudomonas sp. (E = 32-44) [11], lipase PPL Sigma (E = 17-62) [12], lipase PPL Sigma [(S)-sulcatol 2 (ee > 98 per cent) and (R)-sulcatol 2 (ee > 61 per cent)] [13], lipase PPL (E = 19-100) [14], lipase from Burkholeria cepacia-Amano PS (E = 29 -40) [15], lipase from Nigella sativa (E = 2.9-4.1) [16].…”