Journal of Plant Research

, Volume 117, Issue 2, pp 101–107

Flavonoids in translucent bracts of the Himalayan Rheum nobile (Polygonaceae) as ultraviolet shields

  • Tsukasa Iwashina
  • Yuji Omori
  • Junichi Kitajima
  • Shinobu Akiyama
  • Toshisada Suzuki
  • Hideaki Ohba
Original Article

Abstract

UV-absorbing substances were isolated from the translucent bracts of Rheum nobile, which grows in the alpine zone of the eastern Himalayas. Nine kinds of the UV-absorbing substances were found by high performance liquid chromatography (HPLC) and paper chromatography (PC) surveys. All of the five major compounds are flavonoids, and were identified as quercetin 3-O-glucoside, quercetin 3-O-galactoside, quercetin 3-O-rutinoside, quercetin 3-O-arabinoside and quercetin 3-O-[6″-(3-hydroxy-3-methylglutaroyl)-glucoside] by UV, 1H and 13C NMR, mass spectra, and acid hydrolysis of the original glycosides, and direct PC and HPLC comparisons with authentic specimens. The four minor compounds were characterised as quercetin itself, quercetin 7-O-glycoside, kaempferol glycoside and feruloyl ester. Of those compounds, quercetin 3-O-[6″-(3-hydroxy-3-methylglutaroyl)-glucoside] was found in nature for the first time. The translucent bracts of R. nobile accumulate a substantial quantity of flavonoids (3.3–5 mg per g dry material for the major compounds). Moreover, it was clarified by quantitative HPLC survey that much more of the UV-absorbing substances is present in the bracts than in rosulate leaves. Although the flavonoid compounds have been presumed to be the important UV shields in higher plants, there has been little characterisation of these compounds. In this paper, the UV-absorbing substances of the Himalayan R. nobile were characterised as flavonol glycosides based on quercetin.

Keywords

Flavonoids Himalayan alpine plants Quercetin 3-O-[6″-(3-hydroxy-3-methylglutaroyl)-glucoside] Rheum nobile Translucent bracts UV-absorbing substances 

References

  1. Blundstone HAW (1967) Polyphenols of Rheum rhaponticum. I. Flavonol glycosides. Phytochemistry 6:1449–1452CrossRefGoogle Scholar
  2. Bohm BA (1998) Introduction to flavonoids. Harwood Academic, AmsterdamGoogle Scholar
  3. Caldwell MM, Robberecht R, Flint SD (1983) Internal filters: prospects for UV-acclimation in higher plants. Physiol Plant 58:445–450Google Scholar
  4. Geiger H, de Groot-Pfleiderer W (1979) Die Flavon- und Flavonolglykoside von Taxodium distichum. Phytochemistry 18:1709–1710CrossRefGoogle Scholar
  5. Harborne JB, Grayer RJ (1994) Flavonoids and insects. In: Harborne JB (ed) The flavonoids: advances in research since 1986. Chapman and Hall, London, pp 589–618Google Scholar
  6. Iwashina T, Kamenosono K, Yabuya T (1996) Isolation and identification of flavonoid and related compounds as co-pigments from the flowers of Iris ensata. J Jpn Bot 71:281–287Google Scholar
  7. Iwashina T, Konta F, Kitajima J (2001) Anthocyanins and flavonols of Chimonanthus praecox (Calycanthaceae) as flower pigments. J Jpn Bot 76:166–172Google Scholar
  8. Jungblut TP, Schnitzler JP, Heller W, Hertkorn N, Metzger JW, Szymczak W, Sandermann JH (1995) Structures of UV-B induced sunscreen pigments of the Scots Pine (Pinus sylvestris L.). Angew Chem Int Ed Engl 34:312–314CrossRefGoogle Scholar
  9. Karabourniotis G, Papadopoulos K, Papamarkou M, Manetas Y (1992) Ultraviolet-B radiation absorbing capacity of leaf hairs. Physiol Plant 86:414–418CrossRefGoogle Scholar
  10. Kashiwada Y, Nonaka G, Nishioka I (1986) Tannins and related compounds. XLVIII. Rhubarb. (7). Isolation and characterization of new dimeric and trimeric procyanidins. Chem Pharm Bull 34:4083–4091PubMedGoogle Scholar
  11. Kawasaki M, Kanomata T, Yoshitama K (1986) Flavonoids in the leaves of twenty-eight Polygonaceous plants. Bot Mag (Tokyo) 99:63–74Google Scholar
  12. Kikuchi T, Subedi MN, Omori Y, Ohba H (1999) Habitats of alpine plants in Jaljale Himal, eastern Nepal, with special reference to Rheum nobile (Polygonaceae). J Jpn Bot 74:96–104Google Scholar
  13. Kondo N, Kawashima M (2000) Enhancement of the tolerance to oxidative stress in cucumber (Cucumis sativus L.) seedlings by UV-B irradiation: possible involvement of phenolic compounds and antioxidative enzymes. J Plant Res 113:311–317Google Scholar
  14. Li J, Ou-Lee TM, Roda R, Amundson RG, Last RL (1993) Arabidopsis flavonoid mutants are hypersensitive to UV-B radiation. Plant Cell 5:171–179Google Scholar
  15. Mabry TJ, Markham KR, Thomas MB (1970) The systematic identification of flavonoids. Springer, Berlin Heidelberg New York, pp 35–61Google Scholar
  16. Markham KR, Geiger H (1994) 1H Nuclear magnetic resonance spectroscopy of flavonoids and their glycosides in hexadeuterodimethylsulfoxide. In: Harborne JB (ed) The flavonoids: advances in research since 1986. Chapman and Hall, London, pp 441–497Google Scholar
  17. Markham KR, Ternai B, Stanley R, Geiger H, Mabry TJ (1978) Carbon-13 NMR studies of flavonoids-III. Naturally occurring flavonoid glycosides and their acylated derivatives. Tetrahedron 34:1389–1397CrossRefGoogle Scholar
  18. Matsuura S, Iinuma M, Ito E, Takami H, Kagei K (1978) Studies on the constituents of the useful plants. VIII. The constituents of Lespedeza cuneata G. Don. 1. Yakugaku Zasshi 98:1542–1544PubMedGoogle Scholar
  19. Ohba H (1988) The alpine flora of the Nepal Himalayas: an introductory note. In: Ohba H, Malla SB (eds) The Himalayan plants. 1. University of Tokyo Press, Tokyo, pp 19–46Google Scholar
  20. Omori Y, Ohba H (1996) Pollen development of Rheum nobile Hook. f. and Thomson (Polygonaceae), with reference to its sterility induced by bract removal. Bot J Linn Soc 122:269–278CrossRefGoogle Scholar
  21. Omori Y, Ohba H (1999) Thermal condition of the inflorescence of a glasshouse plant, Rheum nobile Hook. f. and Thoms., and microclimatic features of its habitat in Jaljale Himal, east Nepal. Newslett Himalayan Bot 25:5–11Google Scholar
  22. Omori Y, Ohba H (2003) Embryology of a Himalayan glasshouse plant, Rheum nobile Hook. f. and Thoms. (Polygonaceae). J Jpn Bot 78:145–151Google Scholar
  23. Omori Y, Takayama H, Ohba H (2000) Selective light transmittance of translucent bracts in the Himalayan giant glasshouse plant Rheum nobile Hook. f. and Thomson (Polygonaceae). Bot J Linn Soc 132:19–27CrossRefGoogle Scholar
  24. Pachaly P, Klein M (1987) Inhaltsstoffe von Andromeda polifolia. Planta Med 53:442–444Google Scholar
  25. Rai PP (1978) The production of anthraquinones in callus cultures of Rheum palmatum. Lloydia 41:114–116Google Scholar
  26. Skaltsa H, Verykokidou E, Harvala C, Karabouriotis G, Manetas Y (1994) UV-B Protective potential and flavonoid content of leaf hairs of Quercus ilex. Phytochemistry 37:987–990Google Scholar
  27. Servettaz O, Colombo ML, De Bernardi M, Uberti E, Vidari G, Vita-Finzi P (1984) Flavonol glycosides from Dryas octopetala. J Nat Prod 47:809–814PubMedGoogle Scholar
  28. Stapleton AE, Walbot V (1994) Flavonoids can protect maize DNA from the induction of ultraviolet radiation damage. Plant Physiol 105:881–889CrossRefPubMedGoogle Scholar
  29. Terashima I, Masuzawa T, Ohba H (1993) Photosynthetic characteristics of a giant alpine plant, Rheum nobile Hook. f. et Thoms. and of some other alpine species measured at 4,300 m, in the Eastern Himalayas, Nepal. Oecologia 95:194–201Google Scholar
  30. Terashima I, Masuzawa T, Ohba H, Yokoi Y (1995) Is photosynthesis suppressed at higher elevations due to low CO2 pressure? Ecology 76:2663–2668Google Scholar
  31. Tsukaya H (2002) Optical and anatomical characteristics of bracts from the Chinese “glasshouse” plant, Rheum alexandrae Batalin (Polygonaceae), in Yunnan, China. J Plant Res 115:59–63CrossRefPubMedGoogle Scholar
  32. Tutin F, Clewer HWB (1911) The constituents of Rhubarb. J Chem Soc 99:946–967Google Scholar
  33. Wald B, Galensa R, Herrmann K, Grotjahn L, Wray V (1986) Quercetin 3-O-[6″-(3-hydroxy-3-methylglutaroyl)-β-galactoside] from blackberries. Phytochemistry 25:2904–2905CrossRefGoogle Scholar

Copyright information

© The Botanical Society of Japan and Springer-Verlag  2004

Authors and Affiliations

  • Tsukasa Iwashina
    • 1
  • Yuji Omori
    • 2
  • Junichi Kitajima
    • 3
  • Shinobu Akiyama
    • 4
  • Toshisada Suzuki
    • 5
  • Hideaki Ohba
    • 6
  1. 1.Tsukuba Botanical GardenNational Science MuseumTsukuba 305-0005Japan
  2. 2.Yokosuka City MuseumYokosukaJapan
  3. 3.Laboratory of PharmacognosyShowa Pharmaceutical UniversityMachidaJapan
  4. 4.Department of BotanyNational Science MuseumTsukubaJapan
  5. 5.Bioorganic Chemistry, Department of Biochemistry and Food Science, Faculty of AgricultureKagawa UniversityKagawaJapan
  6. 6.Department of Botany, University MuseumUniversity of TokyoTokyoJapan

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