scholarly journals Inhitive ability collagenase of N-(cinnamyl) chitooligosaccharide derivative

2017 ◽  
Vol 20 (K3) ◽  
pp. 83-91
Author(s):  
Xuan Minh Le ◽  
Khanh Duy Nguyen ◽  
Khoa Dang Tran ◽  
Tuan Quoc Tran ◽  
Nghiep Dai Ngo
Keyword(s):  
Molecular Weight ◽  
Room Temperature ◽  
Positive Control ◽  
Living Systems ◽  
Amino Groups ◽  
Animal Cells ◽  
Chemically Modified ◽  
Mtt Method ◽  
Hydrolysis Of ◽  
Derivatives Of

Chitooligosaccharides (COS) with molecular weight 4633 Da and 84.67% of deacetylation were synthesized by hydrolysis of chitosan by cellulase at room temperature (33 ± 1 ° C). This COS, then, were chemically modified by grafting cinnamaldehyde at amino groups on the COS. Derivatives of N- (cinnamyl) chitooligosaccharides (CCOS) synthesized with 50.64% of yield and 72.22% of extent of substitution had inhibitory activity enzyme collagenase (a group of matrix metalloproteinases, enzyme family related to metastatic ability of cancer). Compared with the positive control, 58.23% of the effective to inhibit collagenase of CCOS at 1000 μg/ml concentrate. In addition, the CCOS cytotoxicity of CCOS was also assessed by MTT method, the results showed that non-toxic derivatives of animal cells and thus can be tested and applied in living systems.

The Chemical Evolution of a Nitrogenase Model, 20 Alkyl Molybdates(VI) and the Mechanism of Hydrocarbon Production by Nitrogenase [1]

1982 ◽  
Vol 37 (3) ◽  
pp. 380-385 ◽  
Author(s):  
G. N. Schrauzer ◽  
Laura A. Hughes ◽  
Norman Strampach
Keyword(s):  
Aqueous Solution ◽  
Alkaline Hydrolysis ◽  
Room Temperature ◽  
Bond Cleavage ◽  
Model Compounds ◽  
Hydrocarbon Production ◽  
Acidic Solutions ◽  
Reducing Conditions ◽  
Hydrolysis Of ◽  
Derivatives Of

Abstract Colorless alkylmolybdates(VI) of composition R-MoO3-are generated in aqueous solutions by the alkaline hydrolysis of complexes R-Mo(Bpy)(0)2Br(Bpy = 2,2′-bipyridyl, R = CH3 and higher alkyl). At room temperature in alkaline aqueous solution, the new organometallic derivatives of oxomolybdate(VI) are remarkably resistant against Mo-C bond hydrolysis. Decomposition occurs more rapidly on heating, affording unrearranged alkanes according to the eq.: R-MoO3- + OH-→RH + Mo04=. In acidic solutions, the methylmolybdate(VI) species decomposes with the formation of a mixture of methane and ethane while higher alkylmolybdates carrying hydrogen in the β-position relative to molybdenum undergo Mo-C bond heterolysis by way of β-elimina-tion: R-CH2CH2-MoO3 → Mo+4 (aq) + H+ + R-CH = CH2. The Mo-C bond of alkylmolybdates is resistant to oxidants but is very sensitive to cleavage under reducing conditions. Reductive Mo-C bond cleavage occurs particularly rapidly in the presence of thiols and reduced ferredoxin model compounds. The latter reactions simulate the terminal steps of hydrocarbon producing reactions of nitrogenase with alternate substrates such as CN-, R-CN or R-NC, confirming previous mechanistic conclusions concerning the mechanism of nitrogenase action.

scholarly journals Biodegradation of low molecular weight polyacrylamide under aerobic and anaerobic conditions: effect of the molecular weight

2020 ◽  
Vol 81 (2) ◽  
pp. 301-308 ◽  
Author(s):  
Wenzhe Song ◽  
Yu Zhang ◽  
Amir Hossein Hamidian ◽  
Min Yang
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Carbon Chain ◽  
Anaerobic Treatment ◽  
Low Molecular Weight ◽  
Amino Groups ◽  
Molecular Weights ◽  
Weight One ◽  
Hydrolysis Of ◽  
Aerobic And Anaerobic

Abstract The biodegradation of polyacrylamide (PAM) includes the hydrolysis of amino groups and cleavage of the carbon chain; however, the effect of molecular weight on the biodegradation needs further investigations. In this study, biodegradation of low molecular weight PAM (1.6 × 106 Da) was evaluated in two aerobic (25 °C and 40 °C) and two anaerobic (35 °C and 55 °C) reactors over 100 days. The removal of the low molecular weight PAM (52.0–52.6%) through the hydrolysis of amino groups by anaerobic treatment (35 °C and 55 °C) was much higher than that of the high molecular weight (2.2 × 107 Da, 11.2–17.0%) observed under the same conditions. The molecular weight was reduced from 1.6 × 106 to 6.45–7.42 × 105 Da for the low molecular weight PAM, while the high molecular weight PAM declined from 2.2 × 107 to 3.76–5.87 × 106 Da. The results showed that the amino hydrolysis of low molecular weight PAM is easier than that of the high molecular weight one, while the cleavage of its carbon chain is still difficult. The molecular weights of PAM in the effluents from the two aerobic reactors (25 °C and 40 °C) were further reduced to 4.31 × 105 and 5.68 × 105 Da by the biofilm treatment, respectively. The results would be useful for the management of wastewater containing PAM.

Synthesis of phosphonylmethyl analogues of diribonucleoside monophosphates containing modified internucleotide bond

1987 ◽  
Vol 52 (10) ◽  
pp. 2572-2588 ◽  
Author(s):  
Ivan Rosenberg ◽  
Antonín Holý
Keyword(s):  
Methyl Esters ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Oligonucleotide Synthesis ◽  
Amino Groups ◽  
Methyl Group ◽  
Hydrolysis Of ◽  
Derivatives Of ◽  
Methylene Group ◽  
Phosphotriester Method

Two types of (2'-5')- and (3'-5')-isomers of analogues of diribonucleoside monophosphates derived from O-phosphonylmethyl derivatives of ribonucleosides, differing in the position of the methylene group in the internucleotide bond (type A, B, C, and D) have been synthesized. The compounds were prepared from methyl esters of O-phosphonylmethylribonucleosides I and XVII by a procedure analogous to the phosphotriester method of oligonucleotide synthesis. The phosphonate moiety was protected with the methyl group. After protection of the hydroxyl or amino groups, the compounds I or XVII were condensed with protected ribonucleosides VIII, XI, XIV, XXIII to afford the neutral diesters IX, XII, XV, XXIV, XXVI, and XXVIII which were isolated by short column chromatography on silica gel. Deprotection, ion-exchange chromatography, and semipreparative HPLC gave (2'-5')- and (3'-5')-isomers of both types of O-phosphonylmethyl analogues of diribonucleoside monophosphates (X, XIII and XXV, XXVII). All these compounds are resistant towards cleavage with ribonucleases A and T2 and with snake venom exonuclease. Under conditions of alkaline hydrolysis of RNA, the analogues of the type A and B are completely stable whereas compounds of the type C and D are degraded to form 2'- or 3'-O-phosphonylmethylribonucleosides and 3'-terminal ribonucleosides.

scholarly journals Chemically modified nylons as supports for enzyme immobilization. Polyisonitrile-nylon

1974 ◽  
Vol 143 (3) ◽  
pp. 497-509 ◽  
Author(s):  
Leon Goldstein ◽  
Amihay Freeman ◽  
Mordechai Sokolovsky
Keyword(s):  
Aqueous Medium ◽  
Enzyme Immobilization ◽  
Functional Group ◽  
Carboxyl Groups ◽  
Partial Hydrolysis ◽  
Amino Groups ◽  
Tyrosine Residues ◽  
Chemically Modified ◽  
Reactive Groups ◽  
Hydrolysis Of

Four-component condensations between amine, carboxyl, isocyanide and aldehyde lead to the formation of N-substituted amides (Ugi, 1962). The present paper describes the use of such condensations for the introduction of chemically reactive groups on to the polyamide backbone of nylon. Polyisonitrile-nylon was synthesized by partial hydrolysis of nylon-6 powder, followed by resealing of the newly formed −CO2... NH2− pairs via a four-component condensation, by using acetaldehyde and 1,6-di-isocyanohexane. Polyisonitrile-nylon could also be converted into a diazotizable arylamino derivative, polyaminoaryl-nylon, by a four-component condensation by using a bifunctional amine, pp′-diaminodiphenylmethane, in the presence of an aldehyde and a carboxylate compound. The versatility of four-component condensations involving the isocyanide functional group of polyisonitrile-nylon allowed coupling of proteins, in an aqueous medium at neutral pH, through either their amino or carboxyl groups. Trypsin and papain were bound to polyisonitrile-nylon through their amino groups by a four-component condensation by using acetaldehyde and acetate; conversely, succinyl-(3-carboxypropionyl-)trypsin, pepsin and papain were coupled through their carboxyl groups in the presence of acetaldehyde and an amine (Tris). Diazotized polyaminoaryl-nylon could be utilized for the immobilization of papain, via the tyrosine residues of the enzyme.

scholarly journals Enzymatic Hydrolysis of Marine Collagen and Fibrinogen Proteins in the Presence of Thrombin

Marine Drugs ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 208 ◽  
Author(s):  
Ludmila L. Semenycheva ◽  
Marfa N. Egorikhina ◽  
Victoria O. Chasova ◽  
Natalya B. Valetova ◽  
Yulia L. Kuznetsova ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Enzymatic Hydrolysis ◽  
Main Part ◽  
Room Temperature ◽  
A Value ◽  
Hydrolysis Products ◽  
Native Collagen ◽  
Before And After ◽  
Molecular Fraction ◽  
Hydrolysis Of

Enzymatic hydrolysis of native collagen and fibrinogen was carried out under comparable conditions at room temperature. The molecular weight parameters of proteins before and after hydrolysis by thrombin were monitored by gel-penetrating chromatography (GPC). An analysis of the experiment results shows that the molecular weight parameters of the initial fibrinogen (Fn) and cod collagen (CC) are very similar. High molecular CC decays within the first minute, forming two low molecular fractions. The main part (~80%) falls on the fraction with a value of Mw less than 10 kDa. The initial high molecular fraction of Fn with Mw ~320–340 kDa is not completely hydrolyzed even after three days of control. The presence of low molecular fractions with Mw ~17 and Mw ~10 kDa in the solution slightly increases within an hour and noticeably increases for three days. The destruction of macromolecules of high molecular collagen to hydrolysis products appears almost completely within the first minute mainly to the polymer with Mw ~10 kDa, and enzymatic hydrolysis of fibrinogen proceeds slower than that of collagen, but also mainly to the polymer with Mw ~10 kDa. Comparative photos of the surfaces of native collagen, fibrinogen and the scaffold based on them were obtained.

scholarly journals Relationship between isoelectric point of native and chemically modified insulin and liposomal fusion

1989 ◽  
Vol 264 (1) ◽  
pp. 285-287 ◽  
Author(s):  
R N Farías ◽  
A E López Viñals ◽  
E Posse ◽  
R D Morero
Keyword(s):  
Methyl Ester ◽  
Isoelectric Point ◽  
Carboxyl Groups ◽  
Amino Groups ◽  
Chemically Modified ◽  
Glycine Methyl Ester ◽  
Native Insulin ◽  
Ph Range ◽  
Hydrolysis Of ◽  
Fusion Ability

Native insulin causes fusion of negatively charged liposomes in the pH range from 3.0 to 5.5. In marked contrast, insulin with all three amino groups succinylated did not show fusion ability at any pH. On the other hand, insulin amidated with glycine methyl ester with all six carboxyl groups blocked shifted its activity to higher pH, showing a pH range of activity from 3.0 to 7.4. When the carboxyl groups were recovered by hydrolysis of methoxyl groups from glycine methyl ester-treated insulin, the protein obtained (glycyl-insulin with six free carboxyl groups) behaved as native insulin. A good correlation between the isoelectric point values of insulin and its derivatives and their fusion properties was found.

Novel 1,3,4-Thiadiazole Linked Amide Derivatives of Pteridone: Synthesis and Study of Anticancer Activities

2019 ◽  
Vol 17 (1) ◽  
pp. 54-60
Author(s):  
Eeduri R. Devi ◽  
Reddymasu Sreenivasulu ◽  
Koya P. Rao ◽  
Ratnakaram V. Nadh ◽  
Malladi Sireesha
Keyword(s):  
Cell Lines ◽  
Human Cancer ◽  
Positive Control ◽  
Anticancer Activities ◽  
Human Cancer Cell Lines ◽  
Mtt Method ◽  
Amide Derivatives ◽  
Derivatives Of ◽  
A549 Lung ◽  
Mcf 7

Cancer is a second leading cause of death after heart attack, in developing as well as undeveloped countries. It is caused by unregulated growth and metastasis of the abnormal cancer cells. Cancer can be cured by radiation, immunotherapy and chemotherapy, among them; chemotherapy is a good treatment for cancer, in which chemotherapeutic drug is used. The anticancer activity of newly synthesized compounds (13a-j) was carried out on four different types of human cancer cell lines like MCF-7 (breast), A549 (lung), Colo-205 (colon) and A2780 (ovarian) by the MTT method, and compared to etoposide used as a positive control. Among them, compound 13g with electron-withdrawing (3,5-dinitro) group, exhibited more promising activity in all cell lines (MCF-7 = 0.10±0.076 µM, A549 = 0.17±0.039 µM, Colo-205= 0.13±0.022 µM and A2780 = 0.87±0.027µM). This compound may act as lead drug in cancer chemotherapy. In future, this compound can be examined for clinical studies.

scholarly journals Some experiments on vacuum distillation

1929 ◽  
Vol 123 (791) ◽  
pp. 271-284 ◽  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Vacuum Distillation ◽  
Room Temperature ◽  
High Vacuum ◽  
Crude Petroleum ◽  
Petroleum Derivatives ◽  
Vacuum Systems ◽  
Derivatives Of ◽  
Very High

Crude petroleum and various petroleum derivatives have been distilled under conditions practically equivalent to evaporation into a perfect vacuum. Derivatives of very high molecular weight can be fractionated in this way without detectable decomposition. Decomposition (“cracking”) sets in quite suddenly, at temperatures varying from 307° to 340°C. for the oils tried. Greases and oils can be produced having exceedingly low vapour pressures at room temperature: the former permit the free use of ground joints in high- vacuum systems (10 -6 mm.): the latter can replace mercury in condensation pumps, and the liquid-air trap is then unnecessary in many cases, e. g. , the exhaustion of thermionic valves.

α-Glutamic acid-β-naphthylamidase from Neisseria catarrhalis

1969 ◽  
Vol 15 (11) ◽  
pp. 1293-1300 ◽  
Author(s):  
Sidney T. Cox ◽  
Francis J. Behal
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Metal Ion ◽  
Gel Filtration ◽  
Aminopeptidase Activity ◽  
Amino Acid Residues ◽  
Ph Optimum ◽  
Hydrolysis Of ◽  
Derivatives Of

A second bacterial peptidase-like enzyme, arylamidase-II, has been isolated from cell free extracts of Neisseria catarrhalis. Arylamidase-II action is limited primarily to the hydrolysis of α-glutamic acid and α-aspartic acid derivatives of β-naphthylamine and short peptides of glutamic acid. The enzyme was purified 450-fold by gel filtration, ion exchange, and calcium phosphate chromatography. Its pH optimum and molecular weight were 7.7 and 170 000, respectively. Aside from its restricted substrate specificity, arylamidase-II has been found to be closely related in its mechanism of action, molecular weight, pH optimum, and metal ion dependence to arylamidase-I, which catalyzes the hydrolysis of neutral amino acid derivatives of β-naphthylamine. Arylamidase-II exhibits aminopeptidase activity, requiring the amino acid residues in the N-terminal and penultimate position to be of the L-configuration in order for hydrolysis to occur.

Perchlorate and difluorophosphate coordination derivatives of manganese carbonyl

1978 ◽  
Vol 31 (2) ◽  
pp. 267 ◽  
Author(s):  
FL Wimmer ◽  
MR Snow
Keyword(s):  
Mass Spectroscopy ◽  
Room Temperature ◽  
Halide Ions ◽  
Substitution Reactions ◽  
Decomposition Products ◽  
Solvent Molecules ◽  
Ion Yields ◽  
Manganese Carbonyl ◽  
Hydrolysis Of ◽  
Derivatives Of

The complexes Mn(CO)5(OClO3) and Mn(CO)3L2(OClO3) (L = PPh3, P(OPh)3; L2 = bpy*) are formed by abstraction reactions with AgClO4 from the corresponding bromo complexes in dichloromethane. The perchlorato complexes have been characterized by i.r. and mass spectroscopy. They undergo facile substitution reactions in which the perchlorato group is replaced by halide ions (X- = Cl, Br, I), phosphines [PR3 (R = Ph, p- tolyl, m-tolyl), dpe, dpm]* or solvent molecules (MeCN, PhCN, MeOH, Me2CO, py*). Reaction with fluoride ion yields Mn(CO)3F3 plus other decomposition products. When Mn(CO)5X and Mn(CO)3L2X (X = Br) are made to react with AgPF6 in dichloromethane, hydrolysis of the PF6- ion occurs to yield the corresponding difluorophosphato complexes (X = PO2F2-), which have been characterized by i.r., 19F N.M.R. and mass spectroscopy. They are reasonably stable at low temperatures, but decompose at room temperature. The difluorophosphato group is more inert than perchlorato with the rate of substitution decreasing in the order CO ≈ PPh3 > bpy > P(OPh)3.

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