Die Struktur eines pflanzlichen Chinons mit isoprenoider Seitenkette

Kofler, M.; Langemann, A.; Rüegg, R.; Chopard‐dit‐Jean, L. H.; Rayroud, A.; Isler, O.

doi:10.1002/hlca.19590420424

Cited by 63 publications

(17 citation statements)

References 7 publications

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“…Different tocopherols also, have been identified and have been suggested to act as antioxidants for the unsaturated fats deposited in the seeds.The tocopberol content of leaves has been shown to increase during summer and reach a maximum in late autumn or winter (Booth and Hobson-Frohock 1961). Also the amounts of plastoquinones are found to be greater in autumn than in spring (Kofler et al 1959).This paper describes the estimation of bioquinones and a-tocopherol in leaves from tbe same oak tree {Querciis robiir L.). The quinones include vitamin Ki, plastoquinone A (plastoquinone (45)), two plastoquinones here referred to as plastoquinones X and Y, ubiquinone (50) (coenzyme Qio), and a-tocopherylquinone.…”

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confidence: 97%

Seasonal Variations of Bioquinones and α‐Tocopherol in Oak Leaves

Hindberg¹,

Dam²

1965

Physiologia Plantarum

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Seasonal Variations of Bioquinones and α‐Tocopherol in Oak Leaves

Hindberg¹,

Dam²

1965

Physiologia Plantarum

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“…A negative Cravens 2 test for an unsubstituted site on the quinone ring indicated a tetra substituted benzoquinone. Later examination indicated a positive test for a tri-substituted quinone (Kofler et al 1959;Isler et al 1961).The structure of the prenyl side chain remained unclear. At first, it was thought to be 10 prenyl or 50 carbon-long because solensol, which was used as the long chain compound in the synthesis, was thought to have 50 carbons.…”

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confidence: 99%

Discovery of plastoquinones: a personal perspective

Crane

2010

Photosynth Res

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The discovery and the rediscovery of plastoquinone (PQ) are described together with the definition of its structure as a 2,3-dimethyl 5 solanosyl benzoquinone. The discovery, by M. Kofler, was a result of a search for Vitamin K. Its rediscovery was made by me, when I was at The Enzyme Institute of the University of Wisconsin, analyzing animals and plants for the newly discovered coenzyme Q. In green plants, I found another lipophilic quinone in addition to coenzyme Q. Some misleading evidence suggested as if the new quinone had coenzyme Q activity in mitochondria, but improved methods gave negative results. When I found that the quinone was concentrated in chloroplasts, I considered a role for it in photosynthesis analogous to the role of coenzyme Q in mitochondria. After moving to the Chemistry Department, University of Texas at Austin, I used a plain light bulb and some spinach chloroplasts to show that PQ could be involved in photosynthetic redox reactions. This effect was supported by Norman Bishop's restoration of chloroplast electron transport after solvent extraction, with PQ and photoreduction studies by E. R. Redfern and J. Friend in R. A. Morton's laboratory in Liverpool, UK. We also found an additional analog of PQ in addition to a second analog found in Wisconsin. We called the new analogs PQB and PQC. Although we found some restoration effects with PQC, the discovery by W. T. Griffiths in Morton's laboratory, that PQB and PQC consisted of six forms of PQ each, made it more likely that the new analogs were breakdown products. Morton's group established the structure of the PQCs as a series of PQs, with a hydroxyl group on the prenyl side chain, and the PQB series as having fatty acids esterified to the hydroxyl groups of PQC. Possible functions of the analogs are also discussed in this article.

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“…2,3 dimethyl-5~(3'methyl-2'-butenyl-octakis (3'-methyl-2'-butenylene)-1,4 benzoquine (Trenner et al, 1959;Kofler et al, 1959). Plastoquinone homologues are designated as PQ-n, where n indicates the number of isoprenoid units in the side chain.…”

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Effect of quinones on the photoelectric properties of chlorophylla-containing lipid bilayers

Masters

Mauzerall

1978

J. Membrain Biol.

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Summary. A Mueller-Rudin lipid bilayer formed from egg lecithin, cholesterol n-decane, and chlorophyll a when separating asymmetric solutions of oxidant and reductant is capable of developing both a photoconductance and a photovoltage when exposed to continuous light focused on the bilayer region. The incorporation of plastoquinones (PQ-5 or PQ-9) increases the dark and photoconductances up to twenty times. Other quinones and hydroquinones also increased the conductance. The role of pH gradients on the electrical conductivity is discussed in terms of proton and electron transfer across the membrane solution interfaces.

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Die Struktur eines pflanzlichen Chinons mit isoprenoider Seitenkette

Cited by 63 publications

References 7 publications

Seasonal Variations of Bioquinones and α‐Tocopherol in Oak Leaves

Seasonal Variations of Bioquinones and α‐Tocopherol in Oak Leaves

Discovery of plastoquinones: a personal perspective

Effect of quinones on the photoelectric properties of chlorophylla-containing lipid bilayers

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