Aromatic acids

The efficient synthesis of 12-substituted-3,4,4a,5,12,12a-hexahydrobenzo[b]acridine-1,6,11(2H)-triones starting from 2-amino-1,4-naphthoquinone, 1,3-cyclohexanedione, and different (hetero)aromatic aldehydes was developed. These reactions were carried out in acetic acid under microwave irradiation in the presence of p-toluenesulfonic acid as catalyst. The structure of the newly synthesized compounds were confirmed employing spectroscopic data as well as elemental analysis. The plausible mechanism of these three-component domino reactions was also described.

7p dianmotminh02 03-05-2024 4 1   Download

Synthesis of pyrano-chromenes and pyrano-pyrans was developed by three-component reactions of kojic acid and aromatic aldehydes with dimethone and malononitrile, catalyzed with nano-Bi2O3-ZnO and nano-ZnO, respectively.

12p tocectocec 25-05-2020 14 2   Download

Synthesis of cyclic amide corrosion inhibitors based on C8-C18 fatty acids from Vietnam crude oil is researched. Amides used for this proces are aromatic amides and saturated cyclic amides, namely aniline, antranilic acid, diphenylamine, 1-naphtylamine and xyclohexylamine.

6p uocvong03 24-09-2015 33 2   Download

Two derivatives of 2-thioxoquinazolin-4(3H)-one including compounds 3 and 5 were synthesized by cyclization reaction of anthranilic acid with ethyl isothiocyanate and phenyl isothiocyanate, respectively. Eight novel derivatives of 2-thioxoquinazolin-4(3H)-one including compounds (7a-h) were synthesized by cyclization reaction of derivatives of anthranilic acid with aromatic amines and carbon disulfide in potassium hydroxide/methanol. The obtained compounds were structurally determined by IR, MS, 1 H NMR and 13 C NMR analysis method.

6p uocvong03 24-09-2015 44 3   Download

The fermentation of cassava which normally takes 3-4 days during village processing can be shortened to 24h by seeding a fresh pulp with cassava juice 4 days old. In the work described here, a further attempt has been made to elucidate the nature of biochemical reactions taking place during fermentation, and to establish the optimum conditions which could be utilised in a modern industry based on this process.

6p cscpubka 05-05-2014 63 5   Download

The ability of yeasts to grow in the presence of weak organic acid preservatives is an important cause of food spoilage. Many of the determinants of acetate resistance inSac-charomyces cerevisiae differ from the determinants of resistance to the more lipophilic sorbate and benzoate. Interestingly,we show in this study that hypersensitivity to both acetate and sorbate results when the cells have auxo-trophic requirements for aromatic amino acids.

7p tumor12 20-04-2013 49 4   Download

E2020 (R,S)-1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl]-methyl)piperidine hydrochloride isa piperidine-based ace-tylcholinesterase (AChE) inhibitor that was approved for the treatment of Alzheimer’s disease in the United States. Structure-activity studiesof thisclassof inhibitorshave indicated that both the benzoyl containing functionality and the N-benzylpiperidine moiety are the key featuresfor binding and inhibition of AChE.

12p fptmusic 12-04-2013 41 1   Download

Staphylococcal nuclease (SNase) is a model protein that contains one domain and no disulfide bonds. Its stability in the native state may be maintained mainly by key amino acids. In this study, two point-mutated proteins each with a single base substitution [alanine for tryptophan (W140A) and alanine for lysine (K133A)] and two truncated fragment proteins {positions 1–139 [SNase(1–139) or W140O] and positions 1–141 [SNase(1–141) or E142O]} were generated.

7p fptmusic 11-04-2013 39 3   Download

The LmbB1 protein, participating in the biosynthesis of lincomycin,was heterologously expressed inEscherichia coli, purified in its active form, and characterized as a dimer of identical subunits. Methods for purification and analysis of the LmbB1 reaction product were developed. Molecular mass and fragmentation pattern of the product revealed by capillary electrophoresis-mass spectrometry were in agree-ment with its proposed structure, 4-(3-carboxy-3-oxo-propenyl)-2,3-dihydro-1H-pyrrole-2-carboxylic acid.

6p awards 05-04-2013 36 5   Download

Pseudomonas stutzeriOXI is a Gram-negative microorgan-ism able to grow in media containing aromatic hydrocar-bons. A novel lipo-oligosaccharide fromP. stutzeriOX1 was isolated and characterized. For the first time, the pres-ence of two moieties of 4,6-O-(1-carboxy)-ethylidene resi-dues (pyruvic acid) was identified in a core region; these two residues were found to possess different absolute configur-ation. The structure of the oligosaccharide backbone was determined using either alkaline or acid hydrolysis. ...

14p dell39 03-04-2013 44 3   Download

The human UDP-glucuronosyltransferase (UGT) isoforms UGT2B4 and UGT2B7 play a major role in the detoxification of bile acids, steroids and phenols. These two isoforms present distinct but overlapping substrate spe-cificity, sharing common substrates such as the bile acid hyodeoxycholic acid (HDCA) and catechol-estrogens.

9p galaxyss3 21-03-2013 57 4   Download

Pyridine-linked oxidoreductase enzymes ofHelicobacter pylorihave been implicated in the pathogenesis of gastric disease. Previous studies in this laboratory examined a cinnamyl alcohol dehydrogenase that was capable of detoxifying a range of aromatic aldehydes. In the present work, we have extended these studies to identify and characterize an aldoketo reductase (AKR) enzyme present in H. pylori.

10p galaxyss3 07-03-2013 33 4   Download

Mycobacterium tuberculosis, the causative agent of tuberculosis, is assumed to lack carotenoids, which are widespread pigments fulfilling important functions as radical scavengers and as a source of apocarotenoids. In mam-mals, the synthesis of apocarotenoids, including retinoic acid, is initiated by theb-carotene cleavage oxygenases I and II catalyzing either a central or an excentric cleavage of b-carotene, respectively.

12p viettel02 19-02-2013 29 2   Download

The product of theARO10gene from Saccharomyces cerevisiaewas ini-tially identified as a thiamine diphosphate-dependent phenylpyruvate decar-boxylase with a broad substrate specificity. It was suggested that the enzyme could be responsible for the catabolism of aromatic and branched-chain amino acids, as well as methionine.

12p cosis54 05-01-2013 48 9   Download

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: Albumin dialysis improves hepatic encephalopathy and decreases circulating phenolic aromatic amino acids in patients with alcoholic hepatitis and severe liver failure...

8p coxanh_3 27-10-2011 54 4   Download

Để xác định ảnh hưởng của Mucuna pruriens (MP) đến sự biểu hiện của một số gen tổng hợp catecholamine, nghiên cứu này xác định sự thay đổi của hàm lượng mRNA và protein của tyrosine hydroxylase (TH) và aromatic l- amino acid decarboxylase (AADC). TH là enzyme thứ nhất và AADC là enzyme...

7p thulanh3 08-09-2011 76 3   Download

Ngoài các lệnh thông thường, còn có: Open Special : Chứa các cấu trúc hóa học của amino acids, aromatics (hidrocacbon phương hướng), cycloalkanes, …và các dụng cụ thí nghiệm hóa học. List nicknames: Liệt kê tên thông thường của một số chất. Revert : Phục hồi trạng thái tập tin từ lần ra lệnh lưu sau cùng. List Nicknames: Liệt kê tên riêng của cấu trúc và cho phép đưa cấu trúc vào văn bản hiện hành. ...

24p meoancaran 20-03-2011 127 23   Download

Phân phối : Levodopa xuyên qua hàng rào máu-não nhờ vào hệ vận chuyển có thể trung hòa. Levodopa không gắn kết với protein huyết tương và có thể tích phân phối là 57 lít. Ngược lại levodopa, benserazide không xuyên qua hàng rào máu-não ở liều điều trị. Nó tập trung phần lớn ở thận, phổi, ruột non và gan. Chuyển hóa : Levodopa được chuyển hóa theo hai con đường chính là khử carboxyl (decarboxylation) và methyl-hóa (O-methylation) và hai đường phụ là chuyển amin (transamination) và oxy-hóa (oxidation). Men Aromatic amino acid decarboxylase chuyển levodopa thành dopamine. Những...

5p tunhayhiphop 05-11-2010 66 3   Download

Compared with hydrophilic drugs not undergoing transport, lipophilic drugs are more rapidly taken up from the blood into hepatocytes and more readily gain access to mixed-function oxidases embedded in sER membranes. For instance, a drug having lipophilicity by virtue of an aromatic substituent (phenyl ring) (B) can be hydroxylated and, thus, become more hydrophilic (Phase I reaction, p. 34). Besides oxidases, sER also contains reductases and glucuronyl transferases. The latter conjugate glucuronic acid with hydroxyl, carboxyl, amine, and amide groups (p.

12p bigbaby87 04-09-2010 116 10   Download