Lipídeos inéditos foram isolados de matéria insaponificável extraída de sementes de Nigella sativa Linn, usando-se n-hexano. O dienoato e os dois monoésteres inéditos foram identificados por técnicas espectrométricas, incluindo IV, RMN de 1 H e 13 C, espectrometria de massas, e análise química. O dienoato (1) foi identificado como metilnonadeca-15, 17-dienoato e os dois monoésteres foram identificados como pentil hexadec-12-enoato (2) e pentil pentadec-11-enoato (3). Ácido linoleico, ácido oléico, b-sitosterol e stigmasterol foram identificados como parte das estruturas dos lipídeos. Todos os compostos mostraram atividade moderada contra Staphylococcus aureus e baixa atividade contra shigella spp e Klebsiella pneumoniae.Novel lipids were isolated from the unsaponifiable matter extracted from seeds of Nigella sativa Linn by using n-hexane. The new dienoate and two monoesters were the new lipids identified by spectral (IR, 1 H-and 13 C-NMR spectra, mass spectrum, elemental analysis) and chemical analysis. The dienoate (1) was identified as methylnonadeca-15,17-dienoate and two monoesters were identified as pentyl hexadec-12-enoate (2) and pentyl pentadec-11-enoate (3). Linoleic acid, oleic acid, b-sitosterol and stigmasterol were identified as part of the lipid structures. All compounds exhibited moderate activity against Staphylococcus aureus and poor activity against shigella spp, and Klebsiella pneumoniae.Keywords: Nigella sativa, seeds, Ranunculaceae, aliphatic esters
IntroductionNigella sativa Linn., a plant belonging to the family Ranunculaceae, grows as a small herb and is cultivated throughout India and other tropical regions of the world. 1,2 It is commonly known as black cumin seed and kalaungi in Hindi in India. The seed contains alkaloids nigellidine, 3 nigellimine and nigellicine, 4,5 tannin, steroids a-spinasterol, 6 campesterol, cholesterol, stigmasta-7-en3b-ol, stigmasterol and b-sitosterol, flavonoids of trigillin quercetin-3-glucoside, saponin and nigellone. 7,.8 Recent pharmacological investigations of the seed extract revealed that a wide spectrum of biological activities including anti-inflammatory, antidiabetic, analgesic, antibacterial, antifungal, anti-helmintic, 9 bronchodilatory, 10 hypertensive and immunoprotecting activities. 11 The seeds are believed to have carminative, diuretic, lactogoge, stimulatory and diaphoretic properties and are used in the treatment of bronchial asthma and eczema. [12][13][14][15] The hexane and benzene extracts of its seeds were exhibited 67% and 40% post-coital anti-implantation activity at the dose level of 500 mg kg -1 per day, respectively. 16 The present study reports the isolation and structural elucidation of three new lipids (Figure 1) isolated from seeds of Nigella sativa Linn. Linoleic acid, oleic acid, b-sitosterol and stigmasterol were identified as part of the structures of the new lipids.
Results and DiscussionThe novel natural compounds were identified mainly by their 1D ( 1 H and 13 C NMR), 2D ( 1 H-1 H COSY), DEPT and mass spectrometry analy...