SPRINGER BRIEFS IN PLANT SCIENCE Shoib Ahmad Baba Nasheeman Ashraf Apocarotenoids of Crocus sativus L: From biosynthesis to pharmacology 123 SpringerBriefs in Plant Science More information about this series at h ttp://www.springer.com/series/10080 Shoib Ahmad Baba (cid:129) Nasheeman Ashraf Apocarotenoids of Crocus sativus L: From biosynthesis to pharmacology Shoib Ahmad Baba Nasheeman Ashraf Department of Plant biotechnology Department of Plant biotechnology Indian Institute of Integrative Medicine Indian Institute of Integrative Medicine Srinagar, Jammu and Kashmir , India Srinagar , Jammu and Kashmir , India ISSN 2192-1229 ISSN 2192-1210 (electronic) SpringerBriefs in Plant Science ISBN 978-981-10-1898-5 ISBN 978-981-10-1899-2 (eBook) DOI 10.1007/978-981-10-1899-2 Library of Congress Control Number: 2016948214 © Springer Nature Singapore Pte Ltd. 2016 T his work is subject to copyright. 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The registered company address is: 152 Beach Road, #22-06/08 Gateway East, Singapore 189721, Singapore ‘This book is dedicated to my beloved uncle (Bashir A Baba)’ Contents 1 Apocarotenoid Biosynthesis in Crocus sativus L. ................................... 1 1.1 Introduction ........................................................................................ 1 1.2 Apocarotenoid Biosynthesis in C . sativus L. ..................................... 3 1.2.1 Apocarotenoid Biosynthesis Depends on the Availability of Carotenoid Substrates .................................... 3 1.2.2 Carotenoid Cleavage Leads to the Production of Apocarotenoids ...................................................................... 4 1.2.3 Apocarotenoids in C . sativus Are Stored in Glycosylated Form ................................................................ 8 1.2.4 Hydrolysis of Picrocrocin to Safranal ................................... 9 1.3 Regulation of Apocarotenoid Biosynthesis in C . sativus ................... 10 1.3.1 Regulation of Apocarotenoid Biosynthesis by Carotenogenic Enzyme Levels .............................................. 10 1.3.2 Regulation of Carotenoid Degradation .................................. 11 1.3.3 Transcription Factors Regulating Apocarotenoid Biosynthesis .......................................................................... 12 1.4 Site of Synthesis and Transport of Apocarotenoids in C . sativus ...... 13 1.5 Conclusion ......................................................................................... 16 References ................................................................................................... 16 2 Carotenoid Cleavage Dioxygenases of C rocus sativus L. ....................... 23 2.1 Introduction ........................................................................................ 23 2.2 Carotenoid Cleavage Dioxygenase Family of C rocus sativus L. ...... 26 2.3 Structure of Carotenoid Cleavage Dioxygenases .............................. 27 2.4 Reaction Mechanism of Carotenoid Cleavage Dioxygenases: Mono- or Dioxygenase ...................................................................... 28 2.5 Role and Biotechnological Applications of CCDs ............................ 30 2.5.1 Biotic and Abiotic Stress ....................................................... 30 2.5.2 Color, Flavor, and Aroma Compounds .................................. 32 2.5.3 Pollination ............................................................................. 33 2.6 Conclusion ......................................................................................... 34 References ................................................................................................... 34 vii viii Contents 3 Pharmacological Importance of C rocus sativus Apocarotenoids .......... 39 3.1 Introduction ........................................................................................ 39 3.2 Neuroprotective Activity .................................................................... 40 3.3 Anticancer Activity ............................................................................ 46 3.4 Cardioprotection ................................................................................ 47 3.5 Hepatoprotective Activity .................................................................. 49 3.6 Immunological Functions of Saffron Carotenoids and Apocarotenoids .................................................................................. 49 3.7 Antioxidant Activity .......................................................................... 51 3.8 Effects of C . sativus and Its Constituents on Anxiety ........................ 52 3.9 Effects of C. sativus and Its Constituents in Schizophrenia .............. 54 3.10 Conclusion ......................................................................................... 55 References ................................................................................................... 55 About the Authors Dr. Nasheeman Ashraf is currently a scientist at the Indian Institute of Integrative Medicine’s Department of Plant Biotechnology. She completed her PhD at the National Institute of Plant Genomic Research (NIPGR), New Delhi in 2010, and then joined the Indian Institute of Integrative Medicine, Srinagar (CSIR-IIIM) in 2012. Her research has been published in respected journals, including BMC Genomic, BMC Plant biology, PLOS One, the Journal of Plant physiology. She is a member of the American Society of Plant Biologists. Her current research interest is Crocus sativus , and she was involved developing the transcriptome map for Crocus in 2014. This book has been based on years of research carried out in Dr. Nasheeman’s lab. Shoib Ahmad Baba completed his master’s in botany at the University of Kashmir in 2011, and joined the Indian Institute of Integrative Medicine, Srinagar in 2012 to pursue research under the supervision of Dr. Nasheeman Ashraf. He has been working on C rocus sativus from last 5 years and has identifi ed and characterized some of the key genes of apocarotenoid and fl avonoids biosynthesis. Shoib Ahmad Baba’s research has been published in leading journals, such as BMC Genomics and the Journal of Plant Physiology. He was actively involved in developing the transcriptome map of C. sativus in Dr. Nasheeman’s lab. Shoib Ahmad Baba is currently a member of the ‘Insights in Genes and Genomes’ editorial board. ix Chapter 1 Apocarotenoid Biosynthesis in C rocus sativus L. Abstract Apocarotenoids are oxidative cleavage products of carotenoids. These molecules play vital physiological and developmental roles in plants. Besides this, apocarotenoids also hold tremendous pharmacological importance. Apocarotenoids are ubiquitously found across plant kingdom, but Crocus sativus (saffron) is the only source of some unique and economically important apocarotenoids. These apocarotenoids include crocin, picrocrocin, and safranal which besides having phar- macological importance are also responsible for the color, fl avor, and aroma of the world’s costliest spice (saffron). Apocarotenoid biosynthesis in C . sativus is regu- lated throughout the life cycle with active changes in apocarotenoid composition of stigma due to developmental stage-specifi c requirements and in response to external environmental cues. Although the biosynthesis of these unique C . sativus apocarot- enoids has been elucidated to a greater extent, there are still some missing links in the pathway. Besides, only a few studies have been carried out on the regulation, tissue- and developmental-specifi c accumulation, and transport of apocarotenoids in C. sativus as well as in other plants. The present review is an organized attempt to gain insights about the biosynthesis, regulation, and transport of apocarotenoids in C. sativus . Keywords Crocus sativus • Apocarotenoids • Crocin • Safranal • Carotenoid cleav- age dioxygenase 1.1 Introduction Carotenoids are the most prevalent group of pigments found in nature (Britton et al. 2009; Rao and Rao 2 007 ). These molecules contribute to diversity of colors found in many fl owers, fruits, and vegetables which is attributed to the presence of a num- ber of conjugated double bonds in a polyene chain functioning as a chromophore. Carotenoids are synthesized not only in all photosynthetic organisms but also in some non-photosynthetic bacteria and fungi. Animals can’t synthesize carotenoids; however, through dietary intake of carotenoid-containing foods, they accumulate carotenoids in their bodies that contribute to their health and behavior. For instance, some fi sh and birds accumulate dietary carotenoid which boosts their immune © Springer Nature Singapore Pte Ltd. 2016 1 S.A. Baba, N. Ashraf, Apocarotenoids of Crocus sativus L: From biosynthesis to pharmacology, SpringerBriefs in Plant Science, DOI 10.1007/978-981-10-1899-2_1