This acid was synthesized soon after its discovery in alcaptonuric urine by Baumann & Fraenkel (1894) from 2:5-dimethoxybenzaldehyde by successive conversion to the alcohol, chloride and nitrile, followed by hydrolysis. The overall yield was very poor, due mainly to side reactions occurring in the conversion of the chloride to the nitrile. Schoepf & Winterhalder (1940), who studied systematical...

Alkaptonuria is a rare disease in which a deficiency in the homogentisate 1, 2-dioxygenase enzyme results in a buildup of homogentisic acid. Ochronosis, the deposition of excess homogentisic acid in connective tissue, causes brownish-black pigmentation and weakening of the tissue ultimately resulting in chronic inflammation, degeneration, and osteoarthritis. There is currently no definitive cur...

In the course of the experiments demonstrating that the metabolism of the melanin pigment precursors, tyrosine and dihydroxyphenylalanine, increases the vitamin C requirement of the guinea pig (1) it was learned that those animals receiving tyrosine excreted homogentisic acid in the urine. Furthermore, the amount of the metabolite appeared to be inversely proportional to the amount of ascorbic ...

Alkaptonuria, also called endogenous ochronosis, is a rare metabolic autosomal recessive disorder. It occurs by complete inhibition of homogentisic acid oxidase enzyme having its deposition in various tissues. Male patient, 52 years old, sought medical help complaining about progressive appearance of hyperchromic papules on the lateral edge of the second finger of both hands for 02 years. He al...

Vanilmandelic, homogentisic and homovanillic acid excretions were studied in parkinsonian patients on and off L-dopa. Vanilmandelic acid excretions were quantitated both by gas-chromatographic and calorimetric methods. A marked increase in the excretion of this acid was demonstrated in the parkinsonian patient as compared to controls. Although vanilmandelic excretion rises under the influence o...

Penicillium chrysogenurn Q-176に よPhenylacetic Acidの 酸化的代謝 に關す る研 究(第6報) Pen. chyysognum Q-176 の1変 異 種 に よ るHomogentisic Acidの 生成 に つ い て (そ の2)Phenylacetic Acid代 謝 異 常 菌 株 の菌 学 的性 質 磯 野 正 雄(武田 薬品工業株式会社大阪工場) 昭 和28年10月24日 受 理 Oxidative Metabolism of Phenylacetic Acid by Penicillium chrysogenum Q-176. Part 6. The Production of Homogentisic Acid by a Mutant Strain Induced from Pen. chrysogenum Q-17...

Two patients with urinary findings suggestive of alcaptonuria were observed. One was a two-year-old girl of Turkish descent, presenting with dark-stained diapers, black ear wax, and no other stated problem. The second was a 61-year-old North American Indian woman with long-standing rheumatoid arthritis, bluish sclerae, chronic renal failure, and dark urine. Diagnosis of alcaptonuria was confirm...

A 39-year-old man presented with progressive gait disturbance and urinary incontinence. Medical history disclosed nephrolithiasis, dark urine, osteopenia osteoarthrosis for 15 years. Examination crural spastic paraparesis sensory level at T1 hyperpigmentation of the sclerae (figure). Neuroimaging studies cervical spondylotic myelopathy several discs prolapses. Homogentisic acid levels by HPLC w...

Aspergillus fumigatus is the most important airborne fungal pathogen of immunosuppressed humans. A. fumigatus is able to produce dihydroxynaphthalene melanin, which is predominantly present in the conidia. Its biosynthesis is an important virulence determinant. Here, we show that A. fumigatus is able to produce an alternative melanin, i.e., pyomelanin, by a different pathway, starting from L-ty...