Extractives of Australian timbers. VI. Ebelin lactone

Ebelin lactone, formed by hydrolysis of a saponin, is a carbotricyclic triterpene with a novel carbon skeleton. Chemical evidence leading to the structure (I) for ebelin lactone is now presented in detail. Ebelin lactone, C30H46O3, possesses a secondary, equatorial hydroxyl group shown to be the 3β-hydroxyl group located in a typical triterpene ring A (III). Spectroscopic and chemical results show that the remaining two oxygen atoms are present in a γ-lactone ring (XIII). The side- chain has been subjected to oxidative degradations; an examination of the volatile fragments, and the isolation and characterization of the non-volatile C22 octanor compounds indicate that the side-chain has one of four possible structures (XVII). Structure (XVIII) is preferred on biogenetic grounds. The side-chain is attached equatorially; the conjugated triene system is allotted the trans arrangement of the double bonds on spectroscopic evidence. The biogenesis of ebelin lactone is discussed.

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Isolation and characterization of anti-inflammatory peptides derived from trypsin hydrolysis of microalgae protein (Synechococcus sp. VDW)

Food Biotechnology ◽

10.1080/08905436.2019.1673171 ◽

2019 ◽

Vol 33 (4) ◽

pp. 303-324 ◽

Cited By ~ 4

Author(s):

Rutairat Suttisuwan ◽

Saranya Phunpruch ◽

Tanatorn Saisavoey ◽

Papassara Sangtanoo ◽

Nuttha Thongchul ◽

...

Keyword(s):

Isolation And Characterization ◽

Trypsin Hydrolysis ◽

Synechococcus Sp ◽

Anti Inflammatory ◽

Hydrolysis Of

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Isolation and characterization of a γ-type phosphoinositide-specific phospholipase C (PLC-γ2)

Biochemical Journal ◽

10.1042/bj2690013 ◽

1990 ◽

Vol 269 (1) ◽

pp. 13-18 ◽

Cited By ~ 39

Author(s):

Y Homma ◽

Y Emori ◽

F Shibasaki ◽

K Suzuki ◽

T Takenawa

Keyword(s):

Phospholipase C ◽

Column Chromatography ◽

Specific Activity ◽

Polyacrylamide Gel Electrophoresis ◽

Deae Cellulose ◽

Isolation And Characterization ◽

Delta Type ◽

Hydrolysis Of ◽

Cellulose Column

A novel bovine spleen phosphoinositide-specific phospholipase C (PLC) has been identified with respect to immunoreactivity with four independent antibodies against each of the PLC isoenzymes, and purified to near homogeneity by sequential column chromatography. Spleen contains three of the isoenzymes: two different gamma-types [gamma 1 and gamma 2, originally named as PLC-gamma [Rhee, Suh, Ryu & Lee (1989) Science 244, 546-550] and PLC-IV [Emori, Homma, Sorimachi, Kawasaki, Nakanishi, Suzuki & Takenawa (1989) J. Biol. Chem. 264, 21885-21890] respectively] and delta-type of the enzyme, but PLC-gamma 1 is separated from the PLC-gamma 2 pool by the first DEAE-cellulose column chromatography. Subsequently, PLC-delta is dissociated on the third heparin-Sepharose column chromatography. The purified enzyme has a molecular mass of 145 kDa on SDS/polyacrylamide-gel electrophoresis and a specific activity of 12.8 mumol/min per mg with phosphatidylinositol 4,5-bisphosphate as substrate. This enzyme activity is dependent on Ca2+ for hydrolysis of all these phosphoinositides. None of the other phospholipids examined could be its substrate at any concentration of Ca2+. The optimal pH of the enzyme is slightly acidic (pH 5.0-6.5).

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ESTIMATION OF CORTICOSTEROIDS BY THE REDUCTION OF FERRICYANIDE

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y59-040 ◽

1959 ◽

Vol 37 (1) ◽

pp. 391-398 ◽

Cited By ~ 1

Author(s):

N. R. Stephenson

Keyword(s):

Prussian Blue ◽

Blood Sugar ◽

Alkaline Medium ◽

Alkaline Solution ◽

Reducing Power ◽

Hydroxyl Group ◽

Side Chain ◽

Inhibiting Effect ◽

Reducing Activity ◽

Hydrolysis Of

A procedure based on a modification of Folin's micromethod for blood sugar (1, 2) was used to investigate the reducing activity of various corticosteroids. The ferrocyanide produced as a result of the reduction of ferricyanide in alkaline solution was measured photometrically as Prussian blue. With a filter transmitting light at 620 mμ, the relation between the absorbance of the chromogen and the amount of the reducing steroid obeyed Beer's law over the range from 0.005 to 0.050 mg. The oxygen function at C-3 accounted for most of the reducing power of the non-alpha ketolic steroids studied. An oxygen function at C-11 did not affect significantly the reduction of ferricyanide by 17-desoxycorticosteroids. Although the presence of a hydroxyl at C-17 depressed the reducing activity of the alpha-ketol side chain, a fluorine at C-9 and an hydroxyl at C-11 appeared to overcome this inhibiting effect. Evidence was obtained to suggest that a C-16 hydroxyl group was able to increase the reducing action of the alpha-ketolic side chain. Esterification of the C-21 hydroxyl influenced the reduction of ferricyanide only when interference with hydrolysis of the ester in the alkaline medium was experienced.

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Studies on the hydrolysis of cyclophosphamide II. Isolation and characterization of intermediate hydrolytic products

Journal of Heterocyclic Chemistry ◽

10.1002/jhet.5570100113 ◽

1973 ◽

Vol 10 (1) ◽

pp. 55-58 ◽

Cited By ~ 3

Author(s):

Jiban K. Chakrabarli ◽

Orrie M. Friedman

Keyword(s):

Isolation And Characterization ◽

Hydrolysis Of

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Ectoenzymes of the kidney microvillar membrane. Isolation and characterization of the amphipathic form of renal dipeptidase and hydrolysis of its glycosyl-phosphatidylinositol anchor by an activity in plasma

Biochemical Journal ◽

10.1042/bj2610811 ◽

1989 ◽

Vol 261 (3) ◽

pp. 811-818 ◽

Cited By ~ 20

Author(s):

N M Hooper ◽

A J Turner

Keyword(s):

Membrane Anchor ◽

Glycosyl Phosphatidylinositol ◽

Isolation And Characterization ◽

C Terminus ◽

Terminal Amino ◽

Membrane Isolation ◽

Solubilized Form ◽

Triton X ◽

Hydrolysis Of

Renal dipeptidase (EC 3.4.13.11) has been solubilized from pig kidney microvillar membranes with n-octyl-beta-D-glucopyranoside and then purified by affinity chromatography on cilastatin-Sepharose. The enzyme exists as a disulphide-linked dimer of two identical subunits of Mr 45,000 each. The purified dipeptidase partitioned into the detergent-rich phase upon phase separation in Triton X-114 and reconstituted into liposomes consistent with the presence of the glycosyl-phosphatidylinositol membrane anchor. The N-terminal amino acid sequence of the amphipathic, detergent-solubilized, form of renal dipeptidase was identical with that of the hydrophilic, phospholipase-solubilized, form, locating the membrane anchor at the C-terminus of the protein. The glycosyl-phosphatidylinositol anchor of both purified and microvillar membrane renal dipeptidase was a substrate for an activity in pig plasma which displayed properties similar to those of a previously described phospholipase D. The cross-reacting determinant of the glycosyl-phosphatidylinositol anchor was generated by incubation of purified renal dipeptidase with bacterial phosphatidylinositol-specific phospholipase c, whereas the anchor-degrading activity in plasma failed to generate this determinant.

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Hydrolyse von Per(fluorchlor)methylsulfenylchloriden: Isolierung und Charakterisierung stabiler Zwischenstufen / Hydrolysis of Per(fluorochloro)methylsulfenylchlorides: Isolation and Characterization of Stable Intermediates

Zeitschrift für Naturforschung B ◽

10.1515/znb-1985-0109 ◽

1985 ◽

Vol 40 (1) ◽

pp. 32-38

Author(s):

Alois Haas ◽

Wolfgang Wanzke ◽

Nathan Welcman

Keyword(s):

Preparative Scale ◽

Isolation And Characterization ◽

Hydrolysis Of

Hydrolysis of CF3-nClnSCl with water yields the thiosulfinates CF3-nClnSS(O)CF3-nCln and thiosulfonates CF3-nClnSSO2CF3-nCln as stable intermediates. They were synthesized on a preparative scale by special reactions and characterized. A new mechanism, based upon additional reactions of the isolated products, is discussed and extended to the reaction of chlorine with water

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Isolation and characterization of a β-glucosidase from Penicillium decumbens and improving hydrolysis of corncob residue by using it as cellulase supplementation

Enzyme and Microbial Technology ◽

10.1016/j.enzmictec.2010.01.008 ◽

2010 ◽

Vol 46 (6) ◽

pp. 444-449 ◽

Cited By ~ 66

Author(s):

Mei Chen ◽

Yuqi Qin ◽

Ziyong Liu ◽

Kai Liu ◽

Fengshan Wang ◽

...

Keyword(s):

Penicillium Decumbens ◽

Isolation And Characterization ◽

Hydrolysis Of

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CARBOXYLATION OF CROTONYL-CoA BY MAMMALIAN ENZYME SYSTEMS

Canadian Journal of Biochemistry ◽

10.1139/o66-104 ◽

1966 ◽

Vol 44 (6) ◽

pp. 861-878 ◽

Cited By ~ 1

Author(s):

E. Reno Tustanoff ◽

Joseph R. Stern

Keyword(s):

Carbon Dioxide ◽

Enzyme System ◽

Test System ◽

Diabetic Rats ◽

Isolation And Characterization ◽

Unsaturated Acyl ◽

Liver Preparation ◽

Mammalian Enzyme ◽

Hydrolysis Of

In a crude dialyzed ammonium sulfate fraction (35–65% saturation) of rat liver, carbon dioxide fixation into crotonyl-CoA took place when the test system was supplemented with ATP, Mn++, glutathione, Tris–HCl buffer (pH 7.0), and KH14CO3. The products of this reaction were identified after hydrolysis as glutaconic, β-hydroxyglutaric, maionic, and 2-ethylmalonic acids. The isolation and characterization of 5-14C-glutaconyl-CoA indicated a γ-carboxylation reaction. In the presence of endogenous enoyl-CoA hydratase, crotonyl-CoA was carboxylated more readily than β-hydroxybutyryl-CoA, suggesting that the unsaturated acyl compound was the natural substrate for the enzyme system. Carboxylation of crotonyl-CoA was greatly enhanced when liver extracts were prepared from either fasted or alloxan-diabetic rats. Fixation of carbon dioxide into crotonyl-CoA was also demonstrated with an amorphous preparation of propionyl-CoA carboxylase from pig heart. The products of this reaction were identified as radioactive malonic acid and unlabeled acetaldehyde, compounds which resulted from the alkaline hydrolysis of 2-ethylidenemalonyl-CoA, formed by the α-carboxylation of crotonyl-CoA. Evidence is presented that both α- and γ-carboxylation are catalyzed by the crude liver preparation.

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