Efficacy of traditional methods of protecting cattle from tsetse.
A synthesis for the ortho-quinone methide precursor of virgatolide B has been developed.
4-methyl guaiacol 93-51-6 - The Good Scents Company
Piccirillo, V.J. & Hartman, W.C. (1982) Acute oral toxicity (LD50) study with 4-methyl-2,6-dimethoxy phenol in rats. Unpublished report. Submitted to WHO by-the Flavor and Extract Manufacturers' Association of the United States, Washington DC; USA.
The presence of a ketone functiona confers the possibility of rapid metabolism like that of related phenols. Zingerone (3-methoxy-4-hydroxybenzylacetone; No. 730) given to rats as a single oral or intraperitoneal dose of 100 mg/kg bw was excreted in the urine mainly as glucuronic acid and sulfate conjugates. Reduction of the ketone to zingerol (12%) was also observed, with lesser ring hydroxylation to 4(3,4-dihydroxyphenyl)-2-butanone (6%) and side-chain oxidation to 4-hydroxy-3-methoxyphenylacetic acid (8%) (Monge et al., 1976).
Ortho-Quinone Methides in Natural Product Synthesis
In humans, the bulk of the radioactivity was excreted as the ether insoluble glucuronide of a metabolite in which the ring methyl group and one tert-butyl methyl group were oxidized to carboxyl groups, and a methyl group on the other tert-butyl group was also oxidized, probably to an aldehyde group.
Biological application of conjugates derived from oligonucleotides and quinone methides have previously been limited by the slow exchange of their covalent self-adducts and subsequent alkylation of target nucleic acids. To enhance the rates of these processes, a new quinone methide precursor with an electron donating substituent has been prepared. Additionally, this substituent has been placed to the nascent -methylene group of the quinone methide for maximum effect. A conjugate made from this precursor and a 5'-aminohexyloligonucleotide accelerates formation of its reversible self-adduct and alkylation of its complementary DNA as predicted from prior model studies.
The Domestication of ortho-Quinone Methides - Europe …
ft., former Hercules/PFW facility in Middletown, NY; Fleurchem produces a full range of natural isolates, synthetic chemicals & specialities, essential oils and flavors.
This thesis will describe the use ortho-quinone methides and cascade reactions towards the biomimetic synthesis of the penilactones A and B, the peniphenones A-D, virgatolide B and epicolactone.
ortho-Quinone Methides in Natural Product ..
of o-Quinone Methides: Total Synthesis …
Synthesis of 2,4-Unsubstituted Quinoline-3-carboxylic Acid Ethyl Esters from Arylmethyl Azides via a Domino Process.
Diels-Alder Trapping of ortho-Quinone Methides
Generation of ortho-Quinone Methides by p-TsOH on Silica and Their Hetero-Diels-Alder Reactions with Styrenes.
Diels—Alder Trapping of ortho‐Quinone Methides
Synthesis and Cytotoxicity of Novel 2,2'-Bis- and 2,2',2''-Tris-indolyl-methanes-based Bengacarboline Analogs.
ortho-Quinone Methides in Natural Product Synthesis.
At high doses, -cresol (No. 693), -ethylphenol (No. 694), 2-methoxy-4-methylphenol (No. 715), 2-methoxy-4-propylphenol (No. 717), 2-methoxy-4-vinylphenol (No. 725), and 4-allyl-2,6-dimethoxyphenol (No. 726) are oxidized to reactive quinone methide intermediates. Quinone methides are detoxified by glutathione; however, at very high concentrations this detoxication pathway may be saturated. Low concentrations (
of biomimetic natural product syntheses
A Convergent General Strategy for the Functionalized 2-Aryl Cycloalkylfused Chromans: Intramolecular Hetero-Diels-Alder Reactions of ortho-Quinone Methides.
-quinone methides catalyzed by chiral biphenols.
Temporal concentration changes in BHT and BHT-quinone methide were studied following a single oral dose of 800 mg BHT/kg bw in rats, which were monitored in plasma, the GI tract, and some adipose tissues over a 48-hour period using GLC.
with applications in the total synthesis of natural products
BHT was not detected in the plasma at any of the time points, while BHT-quinone methide showed a rapid rise between 12 and 18 h after administration, followed by a gradual decline to 48 h.
coumarins via ortho-quinone methides.
BHT and/or BHT radical was detected in all but the descending aorta, while BHT-quinone methide was not present in any of the samples collected at 30 minutes after administration (Takahashi, 1990).
synthesis of a meroterpenoid Natural Product.
Phenyl salicylate (No. 736) would be expected to be hydrolysed to salicylic acid and phenol. A man was given one 90-mg capsule of phenyl salicylate each hour for 8 h, and his urine was collected for 72 h after the first dose, fractionated into 8-h collection periods. Total urinary phenol showed a peak of 470 mg/kg during the second collection period, when the concentration of free urinary phenol peaked at 25 mg/kg. Approximately 60 h after the first dose, the concentrations of total and free-urinary phenol had returned to-baseline levels,(7 and 1 mg/kg, respectively) (Fishbeck et al., 1975). Methyl salicylate, a related substance; was hydrolysed in rats, dogs; and humans in vivo (Davison et al., 1961).
"I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."
"Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."
"Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."
"Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."
"Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."
"Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."