The 4α-demethylation of lanostenone

Carr, Katherine H.; Saxton, Helen M.; Sutherland, J. K.

doi:10.1039/p19880001599

Cited by 26 publications

(13 citation statements)

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“…The saturated analogues 1-p-menthen-9-yl 2-methyl butanoate 9 and 1-p-menthen-9-yl 3-methyl butanoate 10 were prepared by esterification of both (+)-(4R)-1-p-menthen-9-ol (1R)-8 and (-)-(4S)-1-p-menthen-9-ol (1S)-8. These were prepared by selective hydroboration/oxidation with disiamylborane on the exocyclic C=C bond of (R)-or (S)-limonene, as described by Carr et al [14] According to the literature, 2 has been reported in Artemisia absinthium [15] and 5 has been reported in the kumquat Fortunella japonica Swingle. [16] 1,8(10)-p-menthadien-9-yl 2-methylbutanoate 6, 1,8(10)-p-menthadien-9-yl 3-methylbutanoate 7, 1-p-menthen-9-yl 2-methylbutanoate 9 and 1-p-menthen-9-yl 3-methyl butanoate 10 are reported here for the first time in a natural product.…”

Section: Resultsmentioning

confidence: 99%

“…Yield 83%, purity 98%, ee 98%. MS: m/z 134 (39), 119 (86), 106 (100), 105 (38), 94 (19), 93 (32), 92 (38), 91 (51), 84 (8), 79 (39), 77 (18), 68 (23), 67 (24), 57 (49), 41(14). 1 H-NMR: 1.16 (t, J = 7.5 Hz, 3H); 1.45-1.55 (m, 1H); 1.65 (br s, 3H); 1.83-2.24 (m, total 6H); 2.37 (q, J = 7.5 Hz, 2H); 4.59 (br s, 2H); 4.97 (br s, 1H); 5.05 (dd, J = 1.1 Hz, 1H); 5.38-5.42 (m, 1H) 13.…”

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Novel terpenyl esters from Australian finger lime (Citrus australasica) peel extract

Delort

Jaquier

2009

Flavour & Fragrance J

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The volatile constituents of the peel solvent extract of the Australian finger lime Citrus australasica were analysed by GC-MS. Besides limonene, isomenthone was a major component, which is rare in Citrus species. Six new terpenyl esters were also identified and confirmed by chemical synthesis: citronellyl 2-methylbutanoate; 1,8(10)-p-menthadien-9-yl propanoate; 1,8(10)-p-menthadien-9-yl 2-methylbutanoate; 1,8(10)-p-menthadien-9-yl 3-methylbutanoate; 1-p-menthen-9-yl 2-methylbutanoate; and 1-p-menthen-9-yl 3-methylbutanoate. To the best of our knowledge, the last four compounds have never before been identified in a natural product extract.

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Section: Resultsmentioning

confidence: 99%

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confidence: 99%

Novel terpenyl esters from Australian finger lime (Citrus australasica) peel extract

Delort

Jaquier

2009

Flavour & Fragrance J

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“…The present paper also presents evidence of a new kind in support of 'free' nitric oxide as an intermediate. Some of the findings have been summarised in a short preliminary report [18].…”

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The energy‐conserving nitric‐oxide‐reductase system in Paracoccus denitrificans

Carr

Page

Ferguson

1989

European Journal of Biochemistry

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1. A Clark-type electrode that responds to nitric oxide has been used to show that cytoplasmic membrane vesicles of Paracoccus denitrificans have a nitric-oxide reductase activity. Nitrous oxide is the reaction product. NADH, succinate or isoascorbate plus 2,3,5,6-tetramethyl-1,4-phenylene diamine can act as reductants. The NADH-dependent activity is resistant to freezing of the vesicles and thus the NADH:nitric-oxide oxidoreductase activity of stored frozen vesicles provides a method for calibrating the electrode by titration of dissolved nitric oxide with NADH. The periplasmic nitrite reductase and nitrous-oxide reductase enzymes are absent from the vesicles which indicates that nitric-oxide reductase is a discrete enzyme associated with the denitrification process. This conclusion was supported by the finding that nitric-oxide reductase activity was absent from both membranes prepared from aerobically grown P. denitrificans and bovine heart submitochondrial particles. 2. The NADH: nitric-oxide oxidoreductase activity was inhibited by concentrations of antimycin or myxothiazol that were just sufficient to inhibit the cytochrome bc1 complex of the ubiquinol--cytochrome-c oxidoreductase. The activity was deduced to be proton translocating by the observations of: (a) up to 3.5-fold stimulation upon addition of an uncoupler; and (b) ATP synthesis with a P:2e ratio of 0.75. 3. Nitrite reductase of cytochrome cd1 type was highly purified from P. denitrificans in a new, high-yield, rapid two- or three-step procedure. This enzyme catalysed stoichiometric synthesis of nitric oxide. This observation, taken together with the finding that the maximum rate of NADH:nitric-oxide oxidoreductase activity catalysed by the vesicles was comparable with that of NADH:nitrate-oxidoreductase, is consistent with a role for nitric-oxide reductase in the physiological conversion of nitrate or nitrite to dinitrogen gas. 4. Intact cells of P. denitrificans also reduced nitric oxide in an antimycin- or myxothiazol-sensitive manner. However, nitric oxide was not detected by the electrode during the reduction of nitrate. Nitric-oxide synthesis from nitrate could be detected with cells in the presence of very low concentrations of Triton X-100 which selectively inhibits nitric-oxide reductase activity. 5. Nitric oxide was detected as an intermediate in denitrification by including haemoglobin with an anaerobic suspension of cells that was reducing nitrate. The characteristic spectrum of the nitric oxide derivative of haemoglobin was observed.(ABSTRACT TRUNCATED AT 400 WORDS)

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“…Transition metal catalysts are especially useful for synthesis of some steroids from triterpenoids. Mechanism of chemical hydroxylation of a triterpenoid E -lupanone oxime with palladium catalyst is a good example of this type of C–H bond activation and oxidation (Carr et al 1988 ). E -Lupanone oxime consists of C=N–OH group which is directing sodium chloropalladate to complex with adjacent methyl group.…”

Section: Stereoselective Hydroxylationmentioning

confidence: 99%

Application of microorganisms towards synthesis of chiral terpenoid derivatives

Kuriata-Adamusiak

Strub

Lochyński

2012

Appl Microbiol Biotechnol

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Biotransformations are a standard tool of green chemistry and thus are following the rules of sustainable development. In this article, we describe the most common types of reactions conducted by microorganisms applied towards synthesis of chiral terpenoid derivatives. Potential applications of obtained products in various areas of industry and agriculture are shown. We also describe biological activity of presented compounds. Stereoselective hydroxylation, epoxidation, Baeyer–Villiger oxidation, stereo- and enantioselective reduction of ketones, and various kinetic resolutions carried out by bacteria and fungi have been reviewed. Mechanistic considerations regarding chemical and enzymatic reactions are presented. We also briefly describe modern approaches towards enhancing desired enzymatic activity in order to apply modified biocatalysts as an efficient tool and green alternative to chemical catalysts used in industry.

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The 4α-demethylation of lanostenone

Abstract: Cyclopalladiation of lanostenone oxime occurs at the equatorial 4x-methyl group. Oxidation of the acetate of this complex w i t h Pb(OAc), forms the 4a-acetoxymethyl compound which on reduction and hydrolysis yields 4P-demethyl-lanostenone.

Cited by 26 publications

References 2 publications

Novel terpenyl esters from Australian finger lime (Citrus australasica) peel extract

Novel terpenyl esters from Australian finger lime (Citrus australasica) peel extract

The energy‐conserving nitric‐oxide‐reductase system in Paracoccus denitrificans

Application of microorganisms towards synthesis of chiral terpenoid derivatives

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