Solid; white; odorless. Sinks and mixes with water. (USCG, 1999)
颜色/状态:
Monoclinic tablets, prisms from toluene ... its aqueous solutions soon turn brown
气味:
Faint characteristic odor
味道:
Sweet and bitter taste
蒸汽密度:
3.79 (NTP, 1992) (Relative to Air)
蒸汽压力:
3X10-2 mm Hg at 20 °C (extrapolated)
水溶性:
0.62
大气OH速率常数:
1.04e-10 cm3/molecule*sec
稳定性/保质期:
Discolors in air and light ... its aqueous solution soon turns brown.
自燃温度:
510 °C
分解:
Energy of decomposition (in range 260-420 °C) measured as 0.42 kJ/g by differential scanning calorimetry (DSC), and T-ait24 was determined as 207 °C by adiabatic Dewar tests, with an apparent energy of activation of 114 kJ/mol.
气味阈值:
detection: 8.0 mg/L
折光率:
Index of refraction: 1.604 at 25 °C
解离常数:
pKa1 = 9.45; pKa2 = 12.8
碰撞截面:
114.5 Ų [M-H]- [CCS Type: DT, Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]
Part of the catechol is oxidized with polyphenol oxidase to benzoquinone. Another fraction conjugates in the body with glucuronic, sulfuric, and other acids ... The conjugates hydrolyze easily in the urine with the liberation of the free catechol ...
Catechol yields guaiacol in rat. ... In the rabbit /catechol/ ... yields o-hydroxyphenyl-beta-d-glucuronide, o-hydroxyphenyl sulfate, and hydroxyquinol ... .
Structure-reactivity studies ... undertaken in rat ... results obtained with ... catechol ... show that 2 vicinal hydroxyl groups are a necessary condition for the /methylation/ reaction to take place, providing evidence for mode of action of catechol o-methyl transferase.
IDENTIFICATION AND USE: Catechol is a tablet or colorless crystal, prism or aqueous solution, which discolors to brown on exposure to air and light. It has a faint characteristic odor. It is used as antioxidant in the rubber, chemical, photographic, dye, fat, and oil industries. It was formerly used as an antiseptic. Catechol was found unsafe for use in cosmetics. HUMAN EXPOSURE AND TOXICITY: Catechol contact with the skin has been known to cause an eczematous dermatitis. It is highly irritating upon direct contact; severe eye and deep skin burns result. Well absorbed by skin. Systemic toxicity similar to that of phenol however, catechol may be more likely to cause convulsions and hypertension. At high doses, renal and liver injury may occur. Absorption through the skin, in a few instances, has resulted in symptoms of illness resembling closely those induced by phenol, except for certain central effects (convulsions) that were more marked. Death apparently is initiated by respiratory failure. Catechol was found to be a more harmful toxin than phenol in human blood cells in vitro, since it provokes statistically significant changes in the function of erythrocytes even at low doses. Both compounds induced methemoglobin formation, glutathione depletion and conversion of oxyhemoglobin to methemoglobin, which is associated with superoxide anion production and lead to formation of ferryl hemoglobin, hydrogen peroxide or hydroxyl radicals. It is known that oxidation of catechol leads to formation of semiquinone radicals. Catechol induced DNA damage in human peripheral blood lymphocytes, and in proliferating human T-lymphocytes. Catechol is confirmed animal carcinogen with unknown relevance to humans. ANIMAL STUDIES: Instillation of 100 mg of catechol into the eyes of rabbits caused a moderate conjunctivitis with exudate and corneal opacity that progressed to a severe conjunctivitis, iritis, and widely diffuse corneal opacity at 72 hours. Fourteen days after instillation, the corneas were vascularized, had infiltration of granulation tissue, and were protruding (keratoconus). Hyperemia of the stomach and intestines was reported after lethal oral doses in rats. Repeated absorption of sublethal doses by animals has induced methemoglobinemia, leucopenia and anemia. Death is apparently initiated by respiratory failure. Catechol clearly induced increases in DNA synthesis in rat forestomach epithelium independent of sex. In the glandular stomach, catechol treatment for 4 weeks increased crypt height due to elevation of DNA synthesis and caused submucosal growth of pyloric mucosal cells. Administration of catechol (1.5% in the diet) for 20 weeks induced mild to moderate hyperplasia in the forestomach. Rats fed catechol in the diet at concentrations of 0 or 1.5% for four weeks followed by 0.8% for 47 weeks either with no other exposure or one week after exposure to N-methyl- N'-nitro-N-nitrosoguanidine increased the incidence of forestomach papillomas, glandular stomach adenocarcinomas, squamous-cell carcinomas of the forestomach, and adenocarcinomas in the pyloric region of the glandular stomach in rats. Regenerative cell proliferation due to toxicity plays an important role in catechol-induced glandular stomach carcinogenesis. Catechol also exhibited developmental toxicity in rats. Litter size and weights were reduced at the maternally toxic doses. Malformations involving limbs, tail and urogenital systems were reported at all doses. Catechol was negative in the Ames assay, but induced sister chromatid exchanges in Chinese hamster ovary V79 cells. In in vivo mouse micronucleus assays, in which the conjugation enzymes responsible for detoxication were present, both positive and negative results were reported. ECOTOXICITY STUDIES: Catechol-treated sea bass showed disorders in the metabolic toxicity indicators such as hypoglycemia, low blood urea nitrogen level and decrease of alkaline phosphatase activity.
Evaluation: No epidemiological data relevant to the carcinogenicity of catechol were available. There is sufficient evidence in experimental animals for the carcinogenicity of catechol. OVERALL EVALUATION: Catechol is possibly carcinogenic to humans (Group 2B).
来源:Hazardous Substances Data Bank (HSDB)
毒理性
致癌性证据
A3;已确认对动物有致癌性,但对人类的相关性未知。
A3; Confirmed animal carcinogen with unknown relevance to humans.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
致癌物分类
国际癌症研究机构致癌物:儿茶酚
IARC Carcinogenic Agent:Catechol
来源:International Agency for Research on Cancer (IARC)
毒理性
致癌物分类
国际癌症研究机构(IARC)致癌物分类:2B组:可能对人类致癌
IARC Carcinogenic Classes:Group 2B: Possibly carcinogenic to humans
来源:International Agency for Research on Cancer (IARC)
Pyrocatechol is readily absorbed from the GI tract and through the intact skin of mice, and probably through the lungs ... Part of the catechol ... conjugates in the body with glucuronic, sulfuric, and other acids and is excreted in the urine, with a little "free" pyrocatechol. The conjugates hydrolyze easily in the urine with the liberation of the "free" catechol, which is oxidized by air with the formation of dark-colored substances that impart to the urine a "smokey" appearance.
When mice were exposed to cigarette smoke containing radiolabeled pyrocatechol, pyrocatechol was distributed readily into the blood and tissues; 90% of the radioactivity was excreted in the urine within 24 hr.
来源:Hazardous Substances Data Bank (HSDB)
吸收、分配和排泄
儿茶酚在呼吸系统中被吸收。很少有儿茶酚作为游离儿茶酚通过尿液排出。
Catechol... is absorbed in the respiratory tract. ...Very little is excreted in the urine as free catechol.
The "'S" skin notation in the listing /of the American Conference of Industrial Hygienists (ACGIH)/ refers to the "potential significant contribution to the overall exposure by the cutaneous route, including mucous membrane and the eyes, either by contact with vapors or, of probable greater significance, by direct skin contact with the substance."
We present herein a novel photo‐mediated homolytic C‐S bond formation for the preparation of alkylthiopurines and alkylthiopurine nucleosides. Despite the presence of reactive sites for the Minisci reaction, chemoselective S‐alkylation remained the predominant pathway. This method allows for the late‐stage introduction of a broad spectrum of alkyl groups onto the sulfur atom of unprotective mercaptopurine derivatives, encompassing 2‐, 6‐, and 8‐mercaptopurine rings. Organoborons serve as efficient and eco‐friendly alkylating reagents, providing advantages in terms of readily availability, stability, and reduced toxicity. Further derivatization of the thioetherified nucleosides, together with anti‐tumor assays, led to the discovery of potent anti‐tumor agents with an IC50 value reaching 6.1 µM (Comp. 31 for Jurkat).
Long-chain phenols. Part 18. Conversion of anacardic acid into urushiol
作者:Lam Soot Kiong、John H. P. Tyman
DOI:10.1039/p19810001942
日期:——
(15 : 0)-Anacardic acid (6-pentadecylsalicylic acid), prepared by reduction of unsaturated anacardicacid from Anacardium occidentale, has been converted into anacardic alcohol (6-pentadecylsalicyl alcohol) and thence by oxidation at carbon into anacardaldehyde. Phenolic oxidation of anacardic alcoholled to 8-pentadecyl-1-oxaspiro-[2.5]octa-5,7-dien-4-one, itself readily convertible photochemically
[EN] PHOSPHODIESTERASE INHIBITORS<br/>[FR] INHIBITEURS DE PHOSPHODIESTÉRASE
申请人:US GOV HEALTH & HUMAN SERV
公开号:WO2009089027A1
公开(公告)日:2009-07-16
The invention relates to compounds of formula I useful for inhibiting phosphodiesterase-4.
这项发明涉及到公式I的化合物,用于抑制磷酸二酯酶-4。
New Drug Delivery System for Crossing the Blood Brain Barrier
申请人:Lipshutz H. Bruce
公开号:US20070203080A1
公开(公告)日:2007-08-30
New ubiquinol analogs are disclosed, as well as methods of using these compounds to deliver drug moieties to the body.
新的泛醌类似物被披露,以及利用这些化合物将药物基团输送到人体的方法。
Efficient synthesis of α-substituted-α-arylmethyl phosphonates using trichloroacetimidate C C coupling method
作者:Walid Fathalla、Pavel Pazdera、Samir El-Rayes、Ibrahim.A.I. Ali
DOI:10.1016/j.tet.2018.02.033
日期:2018.4
A simple convenient protocol for the synthesis of diethyl α,α-diaryl methylphosphonate derivatives 5a-f, 6b-f, 7a-f and 8a-f, diethyl α-alkenyl α-aryl methylphosphonates 9a-d and 10a-d and α-(oxoalkyl) α-aryl methylphosphonate 11a-d and 12a-d is described. Trichloroacetimidates 3a-d were treated with activated arenes, styrene, allyltrimethylsilane or silylenol ethers C-nucleophiles in the presence