Chemical compound
Xanthohumol is a natural product found in the female inflorescences of Humulus lupulus , also known as hops. This compound is also found in beer and belongs to a class of compounds that contribute to the bitterness and flavor of hops.[ 2] Xanthohumol is a prenylated chalconoid , biosynthesized by a type III polyketide synthase (PKS) and subsequent modifying enzymes .[ 3] [ 4]
Biosynthesis
Xanthohumol is a prenylated chalconoid derived from a plant type III PKS, and is synthesized in the glandular trichromes of hop cones.[ 2] L-Phenylalanine serves as the starting material, which is converted to cinnamic acid by the PLP-dependent phenylalanine ammonia lyase .[ 5] [ 6] Cinnamic acid is oxidized by cinnamate-4-hydroxylase and loaded onto Coenzyme A (CoA) by 4-coumarate CoA ligase to yield 4-hydroxy-cinnamoyl CoA , the starter unit for PKS extension.[ 5] [ 6] This molecule is extended three times with malonyl CoA , cyclized through a Claisen condensation , and aromatized through tautomerization to form naringenin chalcone (chalconaringenin).[ 5] This intermediate has the potential to form a variety of different products depending on the enzymes that modify the core structure.[ 2] [ 5] In the case of xanthohumol, a prenyltransferase called Humulus lupulus prenyltransferase 1 (HlPT-1) attaches a molecule of dimethylallyl pyrophosphate from the DXP pathway .[ 7] HlPT-1 has a broad substrate specificity and also participates in making other prenylated flavonoids in the hop plant.[ 7] Finally, an O-methyltransferase methylates a phenol substituent using S-adenosyl methionine .[ 6] Total syntheses of xanthohumol and derivatives have been achieved, though extraction from hops remains a primary source.[ 8] [ 9]
The biosynthesis of Xanthohumol utilizes building blocks from plant secondary metabolism, and is catalyzed by a type III PKS and accessory modifying enzymes.
Beer
In commercial beers, the concentration of xanthohumol ranges from about 2 μg/L – 1.2 mg/L.[ 10] During the brewing process, xanthohumol and other prenylated flavonoids are lost as they are converted to the corresponding flavanones .[ 11] Different hop varieties and different beers contain varying quantities of xanthohumol.[ 2]
Research
Xanthohumol is under basic research for its potential biological properties.[ 10] Xanthohumol can be extracted with pressurized hot water.[ 12]
See also
References
^ a b Xanthohumol from hop (Humulus lupus) , Santa Cruz Biotechnology
^ a b c d Stevens, Jan F.; Page, Jonathan E. (May 2004). "Xanthohumol and related prenylflavonoids from hops and beer: to your good health!". Phytochemistry . 65 (10): 1317– 1330. Bibcode :2004PChem..65.1317S . doi :10.1016/j.phytochem.2004.04.025 . ISSN 0031-9422 . PMID 15231405 .
^ Goese, Markus; Kammhuber, Klaus; Bacher, Adelbert; Zenk, Meinhart H.; Eisenreich, Wolfgang (1999-07-15). "Biosynthesis of bitter acids in hops" . European Journal of Biochemistry . 263 (2): 447– 454. doi :10.1046/j.1432-1327.1999.00518.x . ISSN 1432-1033 . PMID 10406953 .
^ Wang, Guodong; Tian, Li; Aziz, Naveed; Broun, Pierre; Dai, Xinbin; He, Ji; King, Andrew; Zhao, Patrick X.; Dixon, Richard A. (November 2008). "Terpene biosynthesis in glandular trichomes of hop" . Plant Physiology . 148 (3): 1254– 1266. doi :10.1104/pp.108.125187 . ISSN 0032-0889 . PMC 2577278 . PMID 18775972 .
^ a b c d M., Dewick, Paul (9 March 2009). Medicinal natural products : a biosynthetic approach . Wiley. ISBN 978-0-470-74168-9 . OCLC 259265604 . {{cite book }}
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^ a b c Nagel, Jana; Culley, Lana K.; Lu, Yuping; Liu, Enwu; Matthews, Paul D.; Stevens, Jan F.; Page, Jonathan E. (January 2008). "EST analysis of hop glandular trichomes identifies an O-methyltransferase that catalyzes the biosynthesis of xanthohumol" . The Plant Cell . 20 (1): 186– 200. doi :10.1105/tpc.107.055178 . ISSN 1040-4651 . PMC 2254931 . PMID 18223037 .
^ a b Tsurumaru, Yusuke; Sasaki, Kanako; Miyawaki, Tatsuya; Uto, Yoshihiro; Momma, Takayuki; Umemoto, Naoyuki; Momose, Masaki; Yazaki, Kazufumi (2012-01-06). "HlPT-1, a membrane-bound prenyltransferase responsible for the biosynthesis of bitter acids in hops". Biochemical and Biophysical Research Communications . 417 (1): 393– 398. doi :10.1016/j.bbrc.2011.11.125 . ISSN 1090-2104 . PMID 22166201 .
^ Khupse, Rahul S.; Erhardt, Paul W. (2007-09-01). "Total Synthesis of Xanthohumol" . Journal of Natural Products . 70 (9): 1507– 1509. doi :10.1021/np070158y . ISSN 0163-3864 . PMID 17844997 .
^ Zhang, Baoxin; Duan, Dongzhu; Ge, Chunpo; Yao, Juan; Liu, Yaping; Li, Xinming; Fang, Jianguo (2015-02-26). "Synthesis of Xanthohumol Analogues and Discovery of Potent Thioredoxin Reductase Inhibitor as Potential Anticancer Agent". Journal of Medicinal Chemistry . 58 (4): 1795– 1805. doi :10.1021/jm5016507 . ISSN 0022-2623 . PMID 25629304 .
^ a b Gerhäuser, Clarissa (September 2005). "Beer constituents as potential cancer chemopreventive agents". European Journal of Cancer . 41 (13): 1941– 1954. doi :10.1016/j.ejca.2005.04.012 . ISSN 0959-8049 . PMID 15953717 .
^ Stevens, Jan F.; Taylor, Alan W.; Clawson, Jeff E.; Deinzer, Max L. (1999-06-01). "Fate of Xanthohumol and Related Prenylflavonoids from Hops to Beer". Journal of Agricultural and Food Chemistry . 47 (6): 2421– 2428. doi :10.1021/jf990101k . ISSN 0021-8561 . PMID 10794646 .
^ A. Gil-Ramírez, J.A. Mendiola, E. Arranz, A. Ruíz-Rodríguez, G. Reglero, E. Ibáñez, F.R. Marín. Highly isoxanthohumol enriched hop extract obtained by pressurized hot water extraction (PHWE). Chemical and functional characterization . Innovative Food Science and Emerging Technologies 2012 October, vol 16 Pages 54-60. doi: 10.1016/j.ifset.2012.04.006 .