Trihydroxyphenyl

PurpurogaHin (5), a red-brown to black mordant dye, forms from electrolytic and other mild oxidations of pyrogaHol (1). The reaction is beHeved to proceed through 3-hydroxy-(9-benzoquinone (2) and 3-hydroxy-6-(3,4,5-trihydroxyphenyl)-(9-benzoquinone (3). The last, in the form of its tautomeric triketonic stmcture, represents the vinylogue of a P-diketone. Acid hydrolysis leads to the formation of (4), foHowed by cyclization and loss of formic acid... 

The methoxy group of methoxythiophenes shows a reactivity which, in many respects, differs appreciably from the reactivity of the corresponding anisoles. Thus, in an attempted Hoesch synthesis with 5-methoxy-2-thenylcyanide (167) and phloroglucinol, the methoxy group reacted instead and 5-(2, 4, 6 -trihydroxyphenyl)-2-thenyl cyanide (168) was obtained. 2-Thenyl cyanide reacts normally in the Hoesch synthesis, Likewise, upon acid hydrolysis of the reaction product of 5-methoxy-2-thienyllithium with benzophenone, (169) was obtained instead of the expected substituted methoxythiophene. No defined products could be isolated from the attempted Claisen rear-... 

Carboxylic acid-5,6-dihydroxy-2-(2, 4, 6 -trihydroxyphenyl)benzofuran Norwedelic acid 318.24 C15H10O8 3082... 

Apometzgerin-6,8-di-C-arabinoside 6-Arabinopyranosyl-8-p-D-glucopyranosyl-5,7-dihydroxy- 2-(3,4,5-trihydroxyphenyl)-4//-l-benzopyran-4-one Hricetin 6-C-arabinoside-8-C-glucoside... 

LC/ESI-MS analyses were applied to determine urinary glucuronidated and sulfated tea catechins after the administration of green tea to humans, mouse and rats [109]. The major conjugates were identified as monoglucuronides and monosulfates of EGC and EC. Besides these metabolites, also G-methyl-EGC-G-glucuronides, O-sulfates and O-methyl-EC-O-sulfates in human urine were detected. Furthermore, the ring-fission metabolites of EGC and (-)-epicatechin, 5-(3 ,4 ,5 -trihydroxyphenyl)-y-valerolactone and 5-(3 ,4 -dihydroxyphenyl)- valerolactone respectively, have been detected in the monoglucuronide and monosulfate forms. 

Harley-Mason has shown that 5,6-dihydroxyindole (29) can also be obtained from /9-(2,4,5-trihydroxyphenyl)ethylamine (101). Oxidation of 101 with potassium ferricyanide, buffered with sodium bicarbonate, gives a deep red solution [presumably containing norepinochrome (106)] from which 29 was obtained, after the solution had been allowed to stand under hydrogen for 24 hours.281... 

Recently, a reducing blood pigment named tunichrome B-l (10) was isolated from the tunicate Ascidia nigra L. and characterized.351 It has a structure derived from three (3,4,5-trihydroxy)phenylalanine units and the trihydroxyphenyl group is suitable for reducing the metal. 

Crystalline derivatives of aliphatic nitriles may be prepared by an application of the Hoesch reaction. Equimolecular proportions of phloroglucinol and the nitrile react in dry ethereal solution in the presence of anhydrous zinc chloride and hydrogen chloride to give an imine hydrochloride, which is converted into a solid alkyl trihydroxyphenyl ketone by hydrolysis. The alkyl 2,4,6-trihydroxy-phenyl ketones are usually highly crystalline solids of sharp melting point and are purified by recrystallisation from hot water. Many contain water of crystallisation which can be removed by drying in vacuo at about 100 °C the melting points of both the hydrated and anhydrous compound should be determined. 

Chemical Name DL-Serine 2-[(2,3,4-trihydroxyphenyl)methyl]hydrazide Common Name -Structural Formula ... 

Recent research (51) has shown that two putative DIF-1 precursors, l-(3,5-dichloro-2,4,6-trihydroxyphenyl)hexan-l-one and l-(3-chloro-2,4,6-trihydroxyphenyl)hexan-l-one, are also inducers of stalk development. This indicates that the desmethyl and desmethyl-monochloro analogs of DIF-1 are sufficient for stalk formation, which does not exclude the possibility that the methyl forms serve a different purpose. A third stalk-inducing compound identified in the same study was 4-methyl-5-pentylbenzene-l,3-diol. 

An example [27] is provided by the recent determination of the rate of intramolecular electron transfer in a copper-containing amine oxidase, Cu -topaNH2/ Cu -topasQ, Eq. 26, where topa represents 3-(2,4,5-trihydroxyphenyl)-l-alanine. 

Benserazide (BZ), 2-amino-3-hydroxy-A, -[(2,3,4-trihydroxyphenyl) methyl] propane hydrazide is an irreversible inhibitor of peripheral L-aromatic amino acid decarboxylase (AADC). The decarboxylase inhibitor drugs, e.g., carbidopa and benserazide, inhibit dopamine production outside the brain and permit direct deliveiy of dopamine (LD metabolite) to the brain. This synergistic therapy also minimizes the side effects such as nausea and vomiting induced by levodopa.1 2 Benserazide at the recommended therapeutic dose does not cross the blood-brain barrier to any significant degree. Synergistic effect of levodopa and benserazide reduces the required dose of levodopa for the optimal and earlier therapeutic response.3... 

Dihydroxyphenyl)(2,4,6-trihydroxyphenyl)methan-one. Benzophenone, 2,3, 4,4, pentahydroxy- C.l. 75240 C.l. Natural Yellow 11 (3,4-Dihydroxyphenyl)(2,4,6-trihydroxyphenyl)methanone EINECS 208-268-2 Fustic extract Kino-yellow Laguncurin Maclurin Maklurin Methanone, (3.4-dihydroxyphenyl)(2,4,6-trihydroxy-phenyl)- Morintannic acid Moritannic acid NSC 83240 Patent Fustin 2,3, 4,4,6-Pentahydroxybenzophenone. Used to dye fabrics. Crystals mp = 222-223° soluble in H2O (0.48 gtlOO ml), more soluble in organic solvents. 

Pomiferin itself (Table 12.1) has been obtained by a more selective synthetic route (ref. 54). In this, 2,4,6-trihydroxyphenyl 3,4-dimethoxybenzyl ketone was... 

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