Sesquiterpenes from potatoes

D. T. Coxon, K. R. Price, J. B. Stothers and A. Stoessl, "Cyclodehydroisolubimln A New Tricyclic Sesquiterpene from Potato Tubers Inoculated with Phytophthora Infestans",... 

A. is isolated from potatoes, avocado pears, cabbage, rose leaves, and numerous trees. A. is a widely distributed sesquiterpene with the skeleton of the io-nones. For the most important data of A. (1), A. /S-D-glucopyranoside (2), and nigellic acid (3) see table. 

Kato N, Imaseki H, Nakashima N, Uritani I (1971) Structure of a new sesquiterpenoid, ipomeamaronol, in diseased sweet potato root tissue. Tetrahedron Lett 843-846 Kawaguchi Y, Ochi T, Takaishi Y, Kawazoe K, Lee KH (2004) New sesquiterpenes from... 

Bicyclic sesquiterpenes include a variety of bioactive compounds including the Solanaceae phytoalexins capsidiol (G61G6) from Capsicum frutescms (pepper) and the Solanum tuberosum (potato) antifungals rishitin (G61C6) and solavetivone (G6-G5) the Ipomoea batatus... 

The effects of sesquiterpene mixtures from leaf extracts of wild and cultivated potatoes on the settling behavior of green peach aphid were studied in dual-choice assays (22). The sesquiterpene fraction of JS. berthaultii had a strong repellent effect on aphid behavior. Due to use of the slow release medium Carboset, this effect was still apparent beyond six hours. The sesquiterpenoid fraction from cv. Chippewa leaves also strongly repelled aphids. The major foliar sesquiterpene in all extracts, B-caryophyllene, had no adverse effect on settling behavior. 

Katsui et al.,76 isolated two phytoalexins sesquiterpenes lubimin (144) and oxylubimin (145) from white potato tubers (Rishri) infected by an incompatible race of Phytophthora infestans. It has already been mentioned that from white potato tubers also have been isolated sesquiterpene rishitin (40). In the year 1971 Metliskii and coworkers77 isolated lubimin (144) along with rishitin (40) from white potato tubers (S.tuberlosum Lubimets ) stressed with various pathogens. 

Other isopentenoids. Many lipids other than steroids ere formed via the isopentenoid pathway. Terpenes and their derivatives are very important in interactions of plants with other organisms. Kuc and coworkers have proposed that fungal elicitors modify isopentenoid pathways in potato, shifting biosynthesis from triterpene alkaloids which are pre-infection inhibitors to sesquiterpene lactone stress metabolites (9). A variety of insect attractants, insect juvenile hormones, inhibitors and plant hormones are terpene derivatives. 

N. Katsul, A. Matsunaga, K. Imalzuml, T. Masamune and K. Tomlyama, "The Structure and Synthesis of Rlshltlnol, A New Sesquiterpene Alcohol from Diseased Potato Tubers",... 

Ipomeamarone. Formula see ipomeanin. C,5H220], Mr 250.34, [aJi> +27 (C2H5OH), a phytoalexin of the class of furan sesquiterpenes. I. was first isolated from sweet potatoes (Ipomoea batatas) afflicted by black rot. liie amount of I. reaches ca. 2 weight-% of the plant after a short time, it then acts as a highly active fungicide. ... 

A hepatotoxic and nephrotoxic, cytostatic metabolic product formed in sweet potatoes under conditions of stress, in particular on infection with Ceratocystisfim-briata or Fusarium solani. The ipomeanols are derived from I. 1-ipomeanol, 4-ipomeanol, 1,4-ipomeadiol, ipomeamaronol, and ipomeamarone. The latter two compounds are sesquiterpenes and cause atypical pneumonia in animals. 

A sesquiterpene phytoalexin, C17H26O4, Mr 294.39, oil, [ain -35.9° (CHCI3) formed, together with rish-itin and many other components (including vetispi-ranes), by potatoes Solarium tuberosum) after infection by the putrefactive bacterium Erwinia carotovora. Deacetylation furnishes phytuberol, C,5H240j, Mr 252.35, oil. P. can also be isolated from the culture medium of potato cell cultures after elicitation with Phy-tophthora infestans. Some sorts of tobacco Nicotiana tabacum) produce P. after infection with various Pseudomonas spp. or the tobacco mosaic virus pretreatment with a cellulase shows the same effect. 

Fig. 2. Biosynthesis of some sesquiterpene phytoalexins. Phytub rin, solavetivone, lubimin, hydroxylu-bimin and rishitin are produced by Phytophthora-iniected potatoes (Soianum tuberosum) and by potato tuber disks treated with Elicitor (see). Capsidiol is a phytoalexin from Capsicum, [P.A.Brindle D.R.Threlfall Biochem. Society Transactions ft (1983) 516-522]...

Bostock R.M., Kuc J.A., Laine R.A. 1981. Eicosapentaenoic and arachidonic acids from Phytophthora infestans elicit fungitoxic sesquiterpenes in the potato.- Science, 212, 67-69. 

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