Botnick, I., Department of Vegetable Crops, Newe ya'Ar Research Center, Agricultural Research Organization, P.O. Box 1021, Ramat Yishay 30095, Israel, Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agricultural, Food and Environmental Quality Sciences, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel
Xue, W., Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
Bar, E., Department of Vegetable Crops, Newe ya'Ar Research Center, Agricultural Research Organization, P.O. Box 1021, Ramat Yishay 30095, Israel
Ibdah, M., Department of Vegetable Crops, Newe ya'Ar Research Center, Agricultural Research Organization, P.O. Box 1021, Ramat Yishay 30095, Israel
Schwartz, A., Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agricultural, Food and Environmental Quality Sciences, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel
Joel, D.M., Deptartment of Phytopathology and Weed Research, Newe ya'Ar Research Center, Agricultural Research Organization, P.O. Box 1021, Ramat Yishay 30095, Israel
Lev, E., Department of Erets Israel Studies, University of Haifa, Haifa 31905, Israel
Fait, A., Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
Lewinsohn, E., Department of Vegetable Crops, Newe ya'Ar Research Center, Agricultural Research Organization, P.O. Box 1021, Ramat Yishay 30095, Israel

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 Historical and traditional uses are extensively documented in ancient texts and historical documents.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. © 2012 by the authors.