- Cucurbitacin
-
Cucubita-5-ene with standard carbon numbering.
Cucurbitacin is any of a class of biochemical compounds that some plants — notably members of the family Cucurbitaceae, that includes the common pumpkins and gourds — developed in order to defend themselves from herbivores. Cucurbitacins are chemically classified as steroids, formally derived from cucurbitane, a triterpene hydrocarbon — specifically, from the unsaturated variant cucurbita-5-ene, or 19-(10→9β)-abeo-10α-lanost-5-ene. They often occur as glycosides.[1]
Cucurbitacins are generally cytotoxic and poisonous to some animals, and some of them are among the bitterest tastes to humans. They and their derivatives have been found in many plant families (including Brassicaceae, Cucurbitaceae, Scrophulariaceae, Begoniaceae, Elaeocarpaceae, Datiscaceae, Desfontainiaceae, Polemoniaceae, Primulaceae, Rubiaceae, Sterculiaceae, Rosaceae, and Thymelaeaceae), in some mushrooms (including Russula and Hebeloma) and even in some marine mollusks.
Variants
The cucurbitacins include:
Cucurbitacin A
- Cucurbitacin A found in some species of Cucumis [1]:1
- Pentanorcucurbitacin A, or 22-hydroxy-23,24,25,26,27-pentanorcucurbit-5-en-3-one C25H40O2, white powder[2]:1
Cucurbitacin B
- Cucurbitacin B from Hemsleya endecaphylla (62 mg/72 g)[3]:4 and other plants; anti-inflammatory, any-hepatotoxic [1]:2
- Cucurbitacin B 2-O-glucoside, from Begonia heracleifolia [1]:3
- 23,24-Dihydrocucurbitacin B from Hemsleya endecaphylla, 49 mg/72 g[3]:5
- 23,24-Dihydrocucurbitacin B 2-O-glucoside from roots of Picrorhiza kurrooa [1]:4
- Deacetoxycucurbitacin B 2-O-glucoside from roots of Picrorhiza kurrooa [1]:5
- Isocucurbitacin B, from Echinocystis fabacea [1]:6
- 23,24-Dihydroisocucurbitacin B 3-glucoside from Wilbrandia ebracteata [1]:7
- 23,24-Dihydro-3-epi-isocucurbitacin B, from Bryonia verrucosa [1]:8
- Pentanorcucurbitacin B or 3,7-dioxo-23,24,25,26,27-pentanorcucurbit-5-en-22-oic acid, C25H36O4, white powder[2]:2
Cucurbitacin C
- Cucurbitacin C, from Cucumis sativus [1]:11
Cucurbitacin D
- Cucurbitacin D, from Trichosanthes kirilowii and many other plants [1]:12
- 3-Epi-isocucurbitacin D, from species of Physocarpus [1]:14
- 22-Deoxocucurbitacin D from Hemsleya endecaphylla, 14 mg/72 g[3]:6
- 23,24-Dihydrocucurbitacin D from Trichosanthes kirilowii [1]:13 also from H. endecaphylla, 80 mg/72 g[3]:3
- 23,24-Dihydro-epi-isocucurbitacin D, from Acanthosicyos horridus [1]:20
- 22-Deoxocucurbitacin D from Wilbrandia ebracteata [1]:21
- Anhydro-22-deoxo-3-epi-isocucurbitacin D from Ecballium elaterium [1]:22
- 25-O-Acetyl-2-deoxycucurbitacin D (amarinin) from Luffa amara [1]:24
- 2-Deoxycucurbitacin D, from Sloanea zuliaensis [1]:23
Cucurbitacin E
- Cucurbitacin E (aelaterin), from roots of Wilbrandia ebracteata. Strong antifeedant for the flea beetle, inhibits cell adhesion [1]:27
- 22,23-Dihydrocucurbitacin E from Hemsleya endecaphylla, 9 mg/72 g[3]:8, and from roots of Wilbrandia ebracteata [1]:28
- 22,23-Dihydrocucurbitacin E 2-glucoside from roots of Wilbrandia ebracteata [1]:29
- Isocucurbitacin E, from Cucumis phrophetarum [1]:30
- 23,24-Dihydroisocucurbitacin E, from Cucumis phrophetarum [1]:31
Cucurbitacin F
- Cucurbitacin F from Elaeocarpus dolichostylus [1]:33
- Cucurbitacin F 25-acetate from Helmseya graciliflora [1]:34
- 23,24-Dihydrocucurbitacin F from Helmseya amabilis [1]:35
- 25-Acetoxy-23,24-dihydrocucurbitacin F from Helmseya amabilis (hemslecin A) [1]:36
- 23,24-Dihydrocucurbitacin F glucoside from Helmseya amabilis [1]:40
- Cucurbitacin II glucoside from Helmseya amabilis [1]:41
- Hexanorcucurbitacin F from Elaeocarpus dolichostylus [1]:43
- Perseapicroside A from Persea mexicana [1]:44
- Scandenoside R9 from Hemsleya panacis-scandens [1]:45
- 15-Oxo-cucurbitacin F from Cowania mexicana [1]:46
- 15-oxo-23,24-dihydrocucurbitacin F from Cowania mexicana [1]:47
- Datiscosides B, D, and H, from Datisca glomerata [1]:48–50
Cucurbitacin G
- Cucurbitacin G from roots of Wilbrandia ebracteata [1]:52
- 3-Epi-isocucurbitacin G, from roots of Wilbrandia ebracteata [1]:54
Cucurbitacin H
- Cucurbitacin H, stereoisomer of cucurbitacin G, from roots of Wilbrandia ebracteata [1]:53
- Cucurbitacin I (elatericin B) from Hemsleya endecaphylla, 10 mg/72 g [3]:7, also from Ecballium elaterium and Citrullus colocynthis, deters feeding by flea beetle [1]:55
- Hexanorcucurbitacin I from Ecballium elaterium [1]:56
- 23,24-Dihydrocucurbitacin I see Cucurbitacin L
- Khekadaengosides D and K from the fruits of Trichosanthes tricuspidata [1]:57,58
- 11-Deoxocucurbitacin I, from Desfontainia spinosa [1]:59
- Spinosides A and B, from Desfontainia spinosa [1]:61,62
- 23,24-dihydro-11-Deoxocucurbitacin I from Desfontainia spinosa [1]:60
Cucurbitacin J
- Cucurbitacin J from Iberis amara [1]:69
- Cucurbitacin J 2-O-β-glucopyranoside from Trichosanthes tricuspidata [1]:71
Cucurbitacin K
- Cucurbitacin K, stereoisomer of cucurbitacin J, [4]:2, from Iberis amara [1]:70
- Cucurbitacin K 2-O-β-glucopyranoside from Trichosanthes tricuspidata [1]:72
Cucurbitacin L
Cucurbitacin O
- Cucurbitacin O from Brandegea bigelovii [1]:73
- Cucurbitacin Q 2-O-glucoside, from Picrorhiza kurrooa [1]:76
- 16-Deoxy-D-16-hexanorcucurbitacin O from Ecballium elaterium [1]:77
- Deacetylpicracin from Picrorhiza scrophulariaeflora [1]:78
- Deacetylpicracin 2-O-glucoside from Picrorhiza scrophulariaeflora [1]:80
- 22-Deoxocucurbitacin O from Wilbrandia ebracteata [1]:83
Cucurbitacin P
- Cucurbitacin P from Brandegea bigelovii [1]:74
Cucurbitacin Q
- Cucurbitacin Q from Brandegea bigelovii [1]:75
Cucurbitacin R
- Cucurbitacin R is actually 23,24-dihydrocucurbitacin D. [1]
Cucurbitacin S
- Cucurbitacin S from Bryonia dioica [1]:84,85
Cucurbitacin T
- Cucurbitacin T, from the fruits of Citrullus colocynthis [1]:86
28/29 Norcucurbitacins
There are several substances that can be seen as derving from cucurbita-5-ene skeleton by loss of one of the methyl groups (28 or 29) attached to carbon 4; often with the adjacent ring (ring A) becoming aromatic. [1]:87–130
Other
Several other cucurbitacins have been found in plants. [1]:152–156,164–165
Occurrence
One of the active constituents of the colocynth fruit (Citrullus colocynthis) is a cucurbitacin.[citation needed]
The 2-O-β-D-glucopyranosides of Cucurbitacins K and L can be extracted with ethanol from fruits of Cucurbita pepo cv dayangua, at concentrations of 40 mg/15 kg and 32mg/15 kg, respectively.[4]
Pentanorcucurbitacins A and B can be extracted with methanol from the stems of Momordica charantia, at concentrations of 1 mg/18 kg and 4.5 mg/18 kg, respectively. [2]
Cucurbitacins B and I, and derivatives of cucurbitacins B, D and E, can be extracted with methanol from dried tubers of Hemsleya endecaphylla at the concentrations shown above.[3]
Uses
Some cucurbitacins have the action of a potent cathartic purgative.[citation needed]
Some cucurbitacins and their derivatives are also cytotoxic. The toxicity of one cucurbitacin is enhanced by the introduction of a double bond at carbon C23, of an acetyl group at C25, or a double bond at carbons C1-C2[citation needed]. It is decreased by reduction of the ketone group at C3, or introduction of a hydroxyl group at C24. The compound cucurbitacin E is particularly cytotoxic; a concentration of 4.5×10−7μg/ml will destroy half of the cancer cells present.[citation needed]
See also
- Hemslecin
- Momordicoside
- Momordicine
- Mogroside
- Neomogroside
- Goyaglycoside
- Picfeltarraegenins I-VI from Picria feltarrae [1]:157–162
- Picfeltarraenone from Picria feltarrae [1]:163
- Picfeltarraenins IA, IB, II–VI from Picria feltarrae
- carnosifloside from Helmseya carnosiflora [1]:166–171
- Scandenosides R1–R8,R10-R11 [1]:172–181
- Siamenoside I [1]:182
References
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd be bf bg bh bi bj bk bl bm bn bo bp bq br bs bt bu bv bw Jian Chao Chen, Ming Hua Chiu, Rui Lin Nie, Geoffrey A. Cordell and Samuel X. Qiu (2005), "Cucurbitacins and cucurbitane glycosides: structures and biological activities" Natural Product Reports, volume 22, pages 386-399 doi:10.1039/B418841C
- ^ a b c Chiy-Rong Chen, Yun-Wen Liao, Lai Wang, Yueh-Hsiung Kuo, Hung-Jen Liu, Wen-Ling Shih, Hsueh-Ling Cheng and Chi-I Chang (2010). "Cucurbitane Triterpenoids from Momordica charantia and Their Cytoprotective Activity in tert-Butyl Hydroperoxide-Induced Hepatotoxicity of HepG2 Cells". Chemical & pharmaceutical bulletin, volume 58, issue 12, pages 1639-1642. doi:10.1248/cpb.58.1639
- ^ a b c d e f g Jian-Chao Chen, Gao-Hong Zhang, Zhong-Quan Zhang, Ming-Hua Qiu, Yong-Tang Zheng, Liu-Meng Yang, Kai-Bei Yu (2008), "Octanorcucurbitane and Cucurbitane Triterpenoids from the Tubers of Hemsleya endecaphylla with HIV-1 Inhibitory Activity". J. Nat. Prod. volume 71, pages 153–155 doi:10.1021/np0704396
- ^ a b c Da-Cheng Wang, Hong-Yu Pan, Xu-Ming Deng, Hua Xiang, Hui-Yuan Gao, Hui Cai, and Li-Jun Wu (2007), "Cucurbitane and hexanorcucurbitane glycosides from the fruits of Cucurbita pepo cv dayangua". Journal of Asian Natural Products Research, volume 9, issue 6, pages 525–529.
Categories:- Laxatives
- Anticancer
- Steroids
- Cucurbitacin A found in some species of Cucumis [1]:1
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