Distribution of Primary and Specialized Metabolites in Nigella sativa Seeds, a Spice with Vast Traditional and Historical Uses

Black cumin (Nigella sativa L., Ranunculaceae) is an annual herb commonly used in the Middle East, India and nowadays gaining worldwide acceptance. Historical and traditional uses are extensively documented in ancient texts and historical documents. Black cumin seeds and oil are commonly used as a traditional tonic and remedy for many ailments as well as in confectionery and bakery. Little is known however about the mechanisms that allow the accumulation and localization of its active components in the seed. Chemical and anatomical evidence indicates the presence of active compounds in seed coats. Seed volatiles consist largely of olefinic and oxygenated monoterpenes, mainly p-cymene, thymohydroquinone, thymoquinone, γ-terpinene and α-thujene, with lower levels of sesquiterpenes, mainly longifolene. Monoterpene composition changes during seed maturation. γ-Terpinene and α-thujene are the major monoterpenes accumulated in immature seeds, and the former is gradually replaced by p-cymene, carvacrol, thymo-hydroquinone and thymoquinone upon seed development. These compounds, as well as the indazole alkaloids nigellidine and nigellicine, are almost exclusively accumulated in the seed coat. In contrast, organic and amino acids are primarily accumulated in the inner seed tissues. Sugars and sugar alcohols, as well as the amino alkaloid dopamine and the saponin α-hederin accumulate both in the seed coats and the inner seed tissues at different ratios. Chemical analyses shed light to the ample traditional and historical uses of this plant

Fatty acid content of <i>Nigella</i> seeds during development.

<p>The unit of the Y-axis is mg g^–1 fresh weight. Each bar represents the mean values of three replicates ±SE.</p

Relative content of central metabolites identified by GC-MS analysis of <i>Nigella</i> seeds during development.

<p>A – relative content of amino acids, B – relative content of carboxylic and other acids, C – relative content of sugars, sugar alcohols and others. Each bar represents the mean values of three replicates±SE.</p

Phenotype (A) and chlorophyll content (B) of <i>Nigella sativa</i> developing seed from 40^th to 70^th DAA.

<p>Phenotype (A) and chlorophyll content (B) of <i>Nigella sativa</i> developing seed from 40^th to 70^th DAA.</p

<i>Nigella</i> communities.

<p>Shown are the <i>Nigella</i> communities, where nodes display higher connectivity to each other than to the rest of the network. The communities were generated using the walktrap-community algorithm. Their stability was confirmed by robustness analysis. Only communities with more than one node are illustrated.</p

Principal component analysis of central metabolites data during seed development in DAA (see legend).

<p>Plot represents 1^st (X-axis) and 2^nd (Y-axis) principal components. Variance explained by each component is indicated in brackets. Shapes represent different developmental clusters.</p

Fixed oil composition of <i>Nigella sativa</i> at 50 DAA and 82 DAA seeds.

<p>Means of three independent determinations originating from three separate plants each±SE. Fatty acid composition is presented as relative percentage (%) of total fatty acid and was analyzed by GC-FID after their transesterification with 2% H₂SO₄ in dry methanol. Identification was accomplished by comparison of sample peak retention times with those of FAME standard mixtures.</p

Comparative analysis of dynamic regulation of main compositions during seed development in <i>Arabidopsis</i> and <i>Nigella</i>.

<p>Total amino acid is the sum of detected free amino acids. The unit for total protein content is µg/seed, all other compositions use ng/seed as unit. Data came from reported paper <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0073061#pone.0073061-Baud1" target="_blank">[16]</a>.</p

Distribution of Primary and Specialized Metabolites in Nigella sativa Seeds, a Spice with Vast Traditional and Historical Uses

Black cumin (&lt;em&gt;Nigella&lt;/em&gt; &lt;em&gt;sativa&lt;/em&gt; L., Ranunculaceae) is an annual herb commonly used in the Middle East, India and nowadays gaining worldwide acceptance. Historical and traditional uses are extensively documented in ancient texts and historical documents. Black cumin seeds and oil are commonly used as a traditional tonic and remedy for many ailments as well as in confectionery and bakery. Little is known however about the mechanisms that allow the accumulation and localization of its active components in the seed. Chemical and anatomical evidence indicates the presence of active compounds in seed coats. Seed volatiles consist largely of olefinic and oxygenated monoterpenes, mainly &lt;em&gt;p-&lt;/em&gt;cymene, thymohydroquinone, thymoquinone, γ-terpinene and α-thujene, with lower levels of sesquiterpenes, mainly longifolene. Monoterpene composition changes during seed maturation. γ-Terpinene and α-thujene are the major monoterpenes accumulated in immature seeds, and the former is gradually replaced by &lt;em&gt;p&lt;/em&gt;-cymene, carvacrol, thymo-hydroquinone and thymoquinone upon seed development. These compounds, as well as the indazole alkaloids nigellidine and nigellicine, are almost exclusively accumulated in the seed coat. In contrast, organic and amino acids are primarily accumulated in the inner seed tissues. Sugars and sugar alcohols, as well as the amino alkaloid dopamine and the saponin α-hederin accumulate both in the seed coats and the inner seed tissues at different ratios. Chemical analyses shed light to the ample traditional and historical uses of this plant