Struktur und Partialsynthese des pflanzlichen Chinons mit isoprenoider Seitenkette

Kofler, M.; Langemann, A.; Rüegg, R.; Gloor, Urs; Schwieter, Ulrich; Würsch, J.; Wiss, Ø.; Isler, O.

doi:10.1002/hlca.19590420655

Cited by 58 publications

(15 citation statements)

References 9 publications

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“…(15) in 300 mL toluene was added dropwise 2.35 mL (33.1 mmol) acetyl chloride (17) in 5 mL toluene. This mixture was stirred overnight, followed by addition of 4.55 mL triethylamine (32.6 mmol) in 5 mL toluene and subsequent dropwise addition of 1.20 mL (16.5 mmol) acetyl chloride (17) in 5 mL toluene. The mixture was stirred for 3 hours before another 2.20 mL (16.5 mmol) triethylamine and 0.60 (8.3 mmol) acetyl chloride (17) were added as before.…”

Section: -Butenenitrile (12) Methods Amentioning

confidence: 99%

“…The mixture was stirred for 3 hours before another 2.20 mL (16.5 mmol) triethylamine and 0.60 (8.3 mmol) acetyl chloride (17) were added as before. The mixture was again stirred for 3 hours before a final 1.10 mL (8.3 mmol) triethylamine and 0.30 mL (4.1 mmol) acetyl chloride (17) were added. The mixture was stirred overnight and then filtrated.…”

Section: -Butenenitrile (12) Methods Amentioning

confidence: 99%

“…Since acetonitrile (20), ethyl acetate (19), ethyl bromoacetate (16) and acetyl chloride (17) are available in all 13 C-enriched forms, all single and combinations of 13 C-labeled positions of the two DielsϪAlder reagents (12 and 13) are accessible, which consequently makes it possible to synthesize 13 C-labeled plastoquinones 1 on all single and combinations of positions.…”

Section: Synthesis Of the Diels؊alder Reagentsmentioning

confidence: 99%

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Synthesis and Spectroscopic Characterization of 1-13C- and 4-13C-Plastoquinone-9

et al. 2002

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Keywords: Plastoquinone-9 / Methyl butynoate / Crotononitrile / 4,4-Dimethoxy-2,3-dimethylbenzoquinone monoketal / 13 C label / Photosynthesis / Photosystem 2 / Mass spectrometry / NMR spectroscopy This paper presents the synthesis of 1-13 C-and 4-13 C-plastoquinone-9 and their characterization with NMR spectroscopy and mass spectrometry. The synthetic scheme has been further adapted to introduce 13 C-labeled plastoquinones on all individual and on each combination of positions in the qui-

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Section: -Butenenitrile (12) Methods Amentioning

confidence: 99%

Section: -Butenenitrile (12) Methods Amentioning

confidence: 99%

Section: Synthesis Of the Diels؊alder Reagentsmentioning

confidence: 99%

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Synthesis and Spectroscopic Characterization of 1-13C- and 4-13C-Plastoquinone-9

et al. 2002

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“…Synthesis of plastoquinone derivatives with different ~0-substituents: 2,3-dimethyl-5-(10-bromodecyl)-l,4-benzoquinone, PQ-10-Br, was synthesized by radical alkylation of PQ0 with 0o-bromoundecanoic acid in the presence of (NH4)2S20 8 and AgNO3; 2,3-dimethyl-5-(10-hydroxydecyl)-l,4-benzoquinone, PO-10-OH, was synthesized by mercury-catalyzed hydration of PQ-10-Br; 2,3-dimethyl-5-(10-acetyloxydecyl)-1,4-benzoquinone, PQ-10-E was synthesized from PQ-10-OH by esterification with freshly made acetyl chloride (Liu et al 1991a). Synthesis of plastoquinone derivatives with different double bonds in the side chain: 2,3-dimethyl-5-geranyl-l,4-benzoquinone, PQ:, was synthesized according to the methods described previously (Kofler et al 1959). 2,3-dimethyl-5-(hepta-2,4-dienyl)-l,4-benzoquinone, PQ-H, 2,3-dimethyl-5 -(nona -2,4 -dienyl) -1,4 -benzoquinone, PQ-N, and 2,3-dimethyl-5-(3,7-dimethylocta-2,4,6-trienyl)-l,4-benzoquinone, PQ-F, were synthesized from PO0 by successive reactions with (1) NaBH4; (2) KHSO 4 and the corresponding allylic alcohols (hepta-2,4-dien-l-ol, nona-2,4-dien-l-ol and 3,7-dimethylocta-2,4,6-trien-l-ol, respectively) and (3) Ag20 (Liu et al 1991a).…”

Section: Organic Synthesismentioning

confidence: 99%

The relationship between the structure of plastoquinone derivatives and their biological activity in Photosystem II of spinach chloroplasts

Liu

Hoff

et al. 1991

Photosynth Res

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The relationship between the structure of reconstituted plastoquinone derivatives and their ability to recover the Hill reaction was investigated by extraction and reconstitution of lyophilized chloroplasts from spinach, followed by monitoring DCIP photoreduction at 600 nm. The results show that: It is not essential that the plastoquinone side chain be an isoprenoid or a phytol; the activity increases with increasing length of the side chain up to 13-15 carbon atoms; for chains longer than 15 carbon atoms, the activity is practically constant. Lipophilic groups (such as -Br) in the side chain increased the activity, hydrophilic groups (such as -OH) decreased the activity. Conjugated double bonds in the side chain decreased the activity greatly, but non-conjugated double bonds had almost no effect on the activity, indicating a requirement of flexibility of the side chain. The activity is decreased in the order of PQ, UbiQ and MQ, showing a large effect of the ring structure.

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“…Its structure was determined (1), and it was synthesized (2). It was proposed that it has an important role in the electron transport system of photosynthesis that is analogous to that of coenzyme Q (II) in mitochondria (3) by acting as an oxidation-reduction carrier in the electron transport system associated with the transformation of light into chemical energy (ATP) and the utilization of the hydrogen of water as a source of reducing power (NADPH2).…”

mentioning

confidence: 99%

Synthesis of Plastoquinone Analogs and Inhibition of Photosynthetic and Mammalian Enzyme Systems

Bøler

Pardini

Mustafa

et al. 1972

Proc. Natl. Acad. Sci. U.S.A.

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New 5-hydroxy-and 5-chloro-6-alkyl-1,4-benzoquinones with one or two methyl groups on the nucleus were synthesized as potential antimetabolites of plastoquinones for biological research on photosynthetic and mammalian enzyme systems; the primary emphasis was on photosynthesis.2,3-Dimethyl-5 -hydroxy -6 -phytyl -1,4 -benzoquinone completely inhibited in chloroplasts the water-dependent electron transport, but photosystem I was insensitive to this analog. The data are consistent with the interpretation that this analog inhibits electron transport in the chain prior to the site of electron donation from the ascorbate-dichlorophenolindophenol couple. Concentrations of 70 MM and 120 ,M of this analog caused about 50 and 100% inhibition, respectively, of cyclic photophosphorylation.2,3-Dimethyl-5-hydroxy-6-phytyl-1 ,4-benzoquinone is a new type of inhibitor of photosynthetic electron transport that specifically inhibits the rate-limiting step between photosystems I and II. Structurally related analogs caused inhibitions in the range of 50-100% in chloroplasts.These analogs showed marginal inhibition in mitochondrial coenzyme Qjo-oxidase systems from beef heart.Plastoquinone-9 (Plastoquinone-9,I), a compound foundpredominately in the chloroplasts of higher plants, is a naturally occurring benzoquinone with an isoprenoid side chain. Its structure was determined (1), and it was synthesized (2). It was proposed that it has an important role in the electron transport system of photosynthesis that is analogous to that of coenzyme Q (II) in mitochondria (3) by acting as an oxidation-reduction carrier in the electron transport system associated with the transformation of light into chemical energy (ATP) and the utilization of the hydrogen of water as a source of reducing power (NADPH2). Data from several experimental approaches indicate that plastoquinone does function in the electron transport system of chloroplasts. The data stem from extraction-restoration studies, spectrophotometric and chemical determination of redox changes, correlation with metabolic function, and changes in electron transport in mutants, as well as its universal distribution in all oxygen-producing photosynthetic organisms (3).To study relationships between structure and activity in respiration, Redfearn and Whittaker (4) evaluated the inhibition of succinoxidase from a heart muscle preparation by both coenzyme Q and l)lastoquinone analogs. They found that inhibitory quinones have at least one unsubstituted position in the nucleus, that the nature of the substituent ortho to the free position was important, and that the inhibitory effect disappeared in the presence of sulfhydryl compounds. Quinones with one unsubstituted position in the nucleus are known to react by a 1,4-addition with molecules containing a thiol group. This reaction might be involved in the mechanism of inhibition by the compounds studied by these investigators.Catlin et al. (5)

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Struktur und Partialsynthese des pflanzlichen Chinons mit isoprenoider Seitenkette

Cited by 58 publications

References 9 publications

Synthesis and Spectroscopic Characterization of 1-13C- and 4-13C-Plastoquinone-9

Synthesis and Spectroscopic Characterization of 1-13C- and 4-13C-Plastoquinone-9

The relationship between the structure of plastoquinone derivatives and their biological activity in Photosystem II of spinach chloroplasts

Synthesis of Plastoquinone Analogs and Inhibition of Photosynthetic and Mammalian Enzyme Systems

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