Camalexin
Names
Preferred IUPAC name
3-(1,3-Thiazol-2-yl)-1H -indole
Identifiers
ChemSpider
ECHA InfoCard
100.236.489
InChI=1S/C11H8N2S/c1-2-4-10-8(3-1)9(7-13-10)11-12-5-6-14-11/h1-7,13H
Key: IYODIJVWGPRBGQ-UHFFFAOYSA-N
InChI=1/C11H8N2S/c1-2-4-10-8(3-1)9(7-13-10)11-12-5-6-14-11/h1-7,13H
Key: IYODIJVWGPRBGQ-UHFFFAOYAV
c1ccc2c(c1)c(c[nH]2)c3nccs3
Properties
C 11 H 8 N 2 S
Molar mass
200.26 g·mol−1
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
Chemical compound
Camalexin (3-thiazol-2-yl-indole ) is a simple indole alkaloid found in the plant Arabidopsis thaliana and other crucifers . The secondary metabolite functions as a phytoalexin to deter bacterial and fungal pathogens.[ 1]
Structure
The base structure of camalexin consists of an indole ring derived from tryptophan . The ethanamine moiety attached to the 3 position of the indole ring is subsequently rearranged into a thiazole ring.
Biosynthesis
While the biosynthesis of camalexin in planta has not been fully elucidated, most of the enzymes involved in the pathway are known and involved in a metabolon complex.[ 2] The pathway starts with a tryptophan precursor which is subsequently oxidized by two cytochrome P450 enzymes.[ 3] The indole-3-acetaldoxime is then converted to indole-3-acetonitrile by another cytochrome P450, CYP71A13.[ 1] A glutathione conjugate followed by a subsequent unknown enzyme is needed to form dihydrocamalexic acid.[ 4] [ 5] A final decarboxylation step by cytochrome P450 CYP71B15, also called phytoalexin deficient4 (PAD3) results in the final product, camalexin.[ 6] [ 7]
Biological activity
Camalexin is cytotoxic against aggressive prostate cancer cell lines in vitro .[ 8]
References
^ a b Nafisi, Majse; Goregaoker, Sameer; Botanga, Christopher J.; Glawischnig, Erich; Olsen, Carl E.; Halkier, Barbara A.; Glazebrook, Jane (2007). "Arabidopsis Cytochrome P450 Monooxygenase 71A13 Catalyzes the Conversion of Indole-3-Acetaldoxime in Camalexin Synthesis" . The Plant Cell . 19 (6): 2039–2052. doi :10.1105/tpc.107.051383 . PMC 1955726 . PMID 17573535 .
^ Mucha, Stefanie; Heinzlmeir, Stephanie; Kriechbaumer, Verena; Strickland, Benjamin; Kirchhelle, Charlotte; Choudhary, Manisha; Kowalski, Natalie; Eichmann, Ruth; Hueckelhoven, Ralph; Grill, Erwin; Kuster, Bernhard; Glawischnig, Erich (2019). "The formation of a camalexin-biosynthetic metabolon" . The Plant Cell . 31 (11): 2697–2710. doi :10.1105/tpc.19.00403 . PMC 6881122 . PMID 31511315 .
^ Glawischnig, E.; Hansen, B. G.; Olsen, C. E.; Halkier, B. A. (2004). "Camalexin is synthesized from indole-3-acetaldoxime, a key branching point between primary and secondary metabolism in Arabidopsis" . Proceedings of the National Academy of Sciences . 101 (21): 8245–8250. Bibcode :2004PNAS..101.8245G . doi :10.1073/pnas.0305876101 . PMC 419588 . PMID 15148388 .
^ Su, Tongbing; Xu, Juan; Li, Yuan; Lei, Lei; Zhao, Luo; Yang, Hailian; Feng, Jidong; Liu, Guoqin; Ren, Dongtao (2011). "Glutathione-Indole-3-Acetonitrile is Required for Camalexin Biosynthesis in Arabidopsis thaliana" . The Plant Cell . 23 (1): 364–380. doi :10.1105/tpc.110.079145 . PMC 3051237 . PMID 21239642 .
^ Geu-Flores, Fernando; Møldrup, Morten Emil; Böttcher, Christoph; Olsen, Carl Erik; Scheel, Dierk; Halkier, Barbara Ann (2011). "Cytosolic γ-Glutamyl Peptidases Process Glutathione Conjugates in the Biosynthesis of Glucosinolates and Camalexin in Arabidopsis" . The Plant Cell . 23 (6): 2456–2469. doi :10.1105/tpc.111.083998 . PMC 3160024 . PMID 21712415 .
^ Zhou, Nan; Tootle, Tina L.; Glazebrook, Jane (1999). "Arabidopsis PAD3, a Gene Required for Camalexin Biosynthesis, Encodes a Putative Cytochrome P450 Monooxygenase" . The Plant Cell . 11 (12): 2419–2428. doi :10.1105/tpc.11.12.2419 . PMC 144139 . PMID 10590168 .
^ Schuhegger, Regina; Nafisi, Majse; Mansourova, Madina; Petersen, Bent Larsen; Olsen, Carl Erik; Svatoš, Aleš; Halkier, Barbara Ann; Glawischnig, Erich (2006). "CYP71B15 (PAD3) Catalyzes the Final Step in Camalexin Biosynthesis" . Plant Physiology . 141 (4): 1248–1254. doi :10.1104/pp.106.082024 . PMC 1533948 . PMID 16766671 .
^ Smith, Basil A.; Neal, Corey L.; Chetram, Mahandranauth; Vo, Baohan; Mezencev, Roman; Hinton, Cimona; Odero-Marah, Valerie A. (2013). "The phytoalexin camalexin mediates cytotoxicity towards aggressive prostate cancer cells via reactive oxygen species" . Journal of Natural Medicines . 67 (3): 607–618. doi :10.1007/s11418-012-0722-3 . PMC 3644009 . PMID 23179315 .