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1.
Bioorg Chem ; 100: 103884, 2020 07.
Article in English | MEDLINE | ID: mdl-32388430

ABSTRACT

Starting from the compound (3,4-dimethoxyphenyl)(2-(3,4-dimethoxyphenyl)cyclopent-1-en-1-yl)methanone (4), two diols and three tetrol derivatives were synthesised. Morover, from the reactions of 1,3-dimethoxybenzene and 1,4-dimethoxybenzene with adipoyl chloride, fifteen new along with nine known compounds were obtained. For the characterizations of compounds, spectroscopic methods such as NMR including DEPT, COSY, HMQC and HMBC experiments and X-ray diffraction were used. The antioxidant activities of novel synthesized seventeen molecules were investigated by analytical methods like ABTS•+ and DPPH• scavenging. Also, reducing power these molecules were investigated by Fe3+, Cu2+, and [Fe3+-(TPTZ)2]3+. Some of the molecules record powerful antioxidant profile when compared to putative standards. The inhibition effects of the phenols compounds against AChE and BChE activities were analysed. Also, these phenols were found as effective inhibitors for AChE, hCA I, hCA II, and BChE with Kis in the range of 122.95 ± 18.41-351.31 ± 69.12 nM for hCA I, 62.35 ± 9.03-363.17 ± 180.1 nM for hCA II, 134.57 ± 3.99-457.43 ± 220.10 nM for AChE, and 27.06 ± 9.12-72.98 ± 9.53 nM for BChE, respectively.


Subject(s)
Antioxidants/chemistry , Carbonic Anhydrase Inhibitors/chemistry , Cholinesterase Inhibitors/chemistry , Hexanones/chemistry , Phenols/chemistry , Antioxidants/chemical synthesis , Antioxidants/pharmacology , Carbonic Anhydrase I/antagonists & inhibitors , Carbonic Anhydrase II/antagonists & inhibitors , Carbonic Anhydrase Inhibitors/chemical synthesis , Carbonic Anhydrase Inhibitors/pharmacology , Chemistry Techniques, Synthetic , Cholinesterase Inhibitors/chemical synthesis , Cholinesterase Inhibitors/pharmacology , Crystallography, X-Ray , Hexanones/chemical synthesis , Hexanones/pharmacology , Humans , Models, Molecular , Phenols/chemical synthesis , Phenols/pharmacology
2.
Biomolecules ; 9(7)2019 06 28.
Article in English | MEDLINE | ID: mdl-31261818

ABSTRACT

Triple-negative breast cancer (TNBC) is highly proliferative and metastatic, and because it lacks three major molecular targets for chemotherapy (estrogen receptor, progesterone receptor, and human epidermal receptor 2), it is extremely refractory. Differentiation-inducing factor 1 (DIF-1) and DIF-3, which are chlorinated alkylphenones, are lead anticancer compounds found in the cellular slime mold Dictyostelium discoideum. Here, we examined the in vitro effects of DIF-1, DIF-3, and 25 DIF derivatives on cell proliferation and serum-induced cell migration in human MDA-MB-231 cells, a model TNBC cell line. We found that Br-DIF-1, a chlorine-to-bromine-substituted derivative of DIF-1, strongly suppressed cell migration (IC50, 3.8 M) with negligible effects on cell proliferation (IC50, >20 M). We then synthesized 18 derivatives of Br-DIF-1 and examined the in vitro effects of these derivatives on cell proliferation and serum-induced cell migration in MDA-MB-231 cells. Among the derivatives, Br-DIF-1(+1), Br-DIF-1(+2), and Br-DIF-3(+2) exhibited strong anti-cell migration activities with IC50 values of 1.5, 1.0, and 3.1 M, respectively, without affecting cell proliferation (IC50, >20 M). These results suggest that these Br-DIF derivatives are good lead compounds for the development of anti-metastatic drugs against TNBC.


Subject(s)
Breast Neoplasms/drug therapy , Dictyostelium/chemistry , Halogens/pharmacology , Hexanones/pharmacology , Hydrocarbons, Chlorinated/pharmacology , Triple Negative Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Female , Halogens/chemistry , Hexanones/chemical synthesis , Hexanones/chemistry , Humans , Hydrocarbons, Chlorinated/chemical synthesis , Hydrocarbons, Chlorinated/chemistry , Structure-Activity Relationship , Triple Negative Breast Neoplasms/metabolism , Triple Negative Breast Neoplasms/pathology
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 129: 307-13, 2014 Aug 14.
Article in English | MEDLINE | ID: mdl-24747853

ABSTRACT

The reaction between 2,5-hexanedione and salicylic acid hydrazide produced two compounds: 2,5-hexanedione bis(salicyloylhydrazone) [HDSH] (ethanol insoluble) and N-(2,5-dimethyl-1H-pyrrol-1-yl)-2-hydroxybenzamide [DPH] (ethanol soluble). HDSH formed complexes with Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and Pd(II) which are characterized by elemental analyses, spectra (IR, (1)H NMR, ESR and MS), thermal and magnetic measurements. The crystals of [Ni(HDSH-2H)(EtOH)(H2O)] and [Cu(HDSH-2H)] were solved having octahedral and square-planar geometries, respectively. The other complexes have the formulae [Co(HDSH-2H)(H2O)2], [Cu(HDSH-H)2], [Zn(HDSH-2H)(H2O)2], [Cd2(HDSH-4H)(H2O)4], [Cd2(HDSH-2H)(H2O)4Cl2]; [Hg(HDSH-2H)] and [Pd2(HDSH-4H)(H2O)4]. The obtained complexes are stable in air and non-hygroscopic. The magnetic moments and electronic spectra of the complexes provide different geometries. The ESR spectra support the mononuclear geometry for [Cu(HDSH-2H)] and [Cu(HDSH-H)2]. The thermal decomposition of the complexes revealed the coordinated waters as well as the end product which is in most cases the metal oxide. The crystal structure of N-(2,5-dimethyl-1H-pyrrol-1-yl)-2-hydroxybenzamide is solved by X-ray technique.


Subject(s)
Benzamides/chemistry , Coordination Complexes/chemistry , Copper/chemistry , Hexanones/chemistry , Hydrazones/chemistry , Nickel/chemistry , Benzamides/chemical synthesis , Coordination Complexes/chemical synthesis , Crystallography, X-Ray , Hexanones/chemical synthesis , Hydrazones/chemical synthesis , Models, Molecular , Spectrum Analysis
4.
Bioorg Med Chem Lett ; 23(2): 562-4, 2013 Jan 15.
Article in English | MEDLINE | ID: mdl-23219702

ABSTRACT

The first report of the antiviral activity of (+)-sattabacin against varicella-zoster virus (VZV) is described. Our results show that (+)-sattabacin potently inhibits the growth of VZV at concentrations in the range of other drugs commonly prescribed for VZV infection. Experiments detailing the synthesis of (+)-sattabacin, quantification of cytotoxicity and gene expression data in human fibroblast cells are also presented. Gene expression data was obtained through microarray analysis from human fibroblast cells exposed to sattabacin in order to identify a possible mechanism by which (+)-sattabacin inhibits VZV replication.


Subject(s)
Antiviral Agents/pharmacology , Herpesvirus 3, Human/drug effects , Hexanones/pharmacology , Antiviral Agents/chemistry , Cell Survival/drug effects , Cells, Cultured , Hexanones/chemical synthesis , Hexanones/chemistry , Humans , Molecular Structure
5.
PLoS One ; 6(7): e21723, 2011.
Article in English | MEDLINE | ID: mdl-21760901

ABSTRACT

We previously discovered a lead compound for strigolactone (SL) biosynthesis inhibitors, TIS13 (2,2-dimethyl-7-phenoxy-4-(1H-1,2,4-triazol-1-yl)heptan-3-ol). Here, we carried out a structure-activity relationship study of TIS13 to discover more potent and specific SL biosynthesis inhibitor because TIS13 has a severe side effect at high concentrations, including retardation of the growth of rice seedlings. TIS108, a new TIS13 derivative, was found to be a more specific SL biosynthesis inhibitor than TIS13. Treatment of rice seedlings with TIS108 reduced SL levels in both roots and root exudates in a concentration-dependent manner and did not reduce plant height. In addition, root exudates of TIS108-treated rice seedlings stimulated Striga germination less than those of control plants. These results suggest that TIS108 has a potential to be applied in the control of root parasitic weeds germination.


Subject(s)
Hexanones/pharmacology , Lactones/pharmacology , Oryza/drug effects , Oryza/growth & development , Triazoles/pharmacology , Biological Assay , Germination/drug effects , Hexanones/chemical synthesis , Hexanones/chemistry , Lactones/metabolism , Seedlings/drug effects , Seedlings/growth & development , Triazoles/chemical synthesis , Triazoles/chemistry
6.
Chem Commun (Camb) ; 47(3): 1015-7, 2011 Jan 21.
Article in English | MEDLINE | ID: mdl-21063612

ABSTRACT

Phosphine catalyzed enantioselective [3+2] cyclizations on 4-substituted 2,6-diarylidenecyclohexanones and 2,4-diarylidene-bicyclo[3.1.0]hexan-3-ones take place with high diastereo- and enantioselectivity levels. The process affords spirocyclic compounds with excellent stereochemical control of up to five stereogenic centres.


Subject(s)
Cyclohexanones/chemistry , Hexanones/chemistry , Phosphines/chemistry , Spiro Compounds/chemistry , Catalysis , Cyclization , Cyclohexanones/chemical synthesis , Hexanones/chemical synthesis , Models, Molecular , Spiro Compounds/chemical synthesis , Stereoisomerism
7.
Molecules ; 15(7): 5045-52, 2010 Jul 23.
Article in English | MEDLINE | ID: mdl-20657407

ABSTRACT

We have developed a Pt(COD)Cl(2)-catalyzed hydrative cyclization of 1,6-diynes leading to the formation of functionalized cyclohexenones in good yields.


Subject(s)
Diynes/chemistry , Hexanones/chemical synthesis , Platinum/chemistry , Catalysis , Cyclization
8.
J Chem Ecol ; 35(6): 733-40, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19444521

ABSTRACT

Adults of both sexes of the cerambycid beetles Xylotrechus colonus (F.) and Sarosesthes fulminans (F.) were attracted to odors produced by male conspecifics in olfactometer bioassays. Analyses of headspace volatiles from adults revealed that male X. colonus produced a blend of (R)- and (S)-3-hydroxyhexan-2-one and (2 S,3 S)- and (2R,3R)-2,3-hexanediol, whereas male S. fulminans produced (R)-3-hydroxyhexan-2-one and (2 S,3R)-2,3-hexanediol. All of these compounds were absent in the headspace of females. Two field bioassays were conducted to confirm the biological activity of the synthesized pheromones: (1) enantiomerically enriched pheromone components were tested singly and in species-specific blends and (2) four-component mixture of racemic 3-hydroxyhexan-2-one plus racemic 2-hydroxyhexan-3-one and the four-component blend of the stereoisomers of 2,3-hexanediols were tested separately and as a combined eight-component blend. In these experiments, adult male and female X. colonus were captured in greatest numbers in traps baited with the reconstructed blend of components produced by males, although significant numbers were also captured in traps baited with (R)-3-hydroxyhexan-2-one alone or in blends with other compounds. Too few adult S. fulminans were captured for a statistical comparison among treatments, but all were caught in traps baited with lures containing (R)-3-hydroxyhexan-2-one. In addition to these two species, adults of two other species of cerambycid beetles, for which pheromones had previously been identified, were caught: Neoclytus a. acuminatus (F.) and its congener Neoclytus m. mucronatus (F.). Cross-attraction of beetles to pheromone blends of other species, and to individual pheromone components that are shared by two or more sympatric species, may facilitate location of larval hosts by species that compete for the same host species.


Subject(s)
Coleoptera/physiology , Glycols/pharmacology , Hexanones/pharmacology , Sex Attractants/pharmacology , Animals , Female , Gas Chromatography-Mass Spectrometry , Glycols/chemical synthesis , Glycols/isolation & purification , Hexanones/chemical synthesis , Hexanones/isolation & purification , Male , Sex Attractants/chemical synthesis , Sex Attractants/isolation & purification , Sexual Behavior, Animal/drug effects , Stereoisomerism
9.
Bioorg Med Chem Lett ; 19(14): 3888-91, 2009 Jul 15.
Article in English | MEDLINE | ID: mdl-19364643

ABSTRACT

The aldol reaction of the endogeneous compounds acetone and methylglyoxal has been studied using organocatalysis in relation to biologically relevant non-enzymatic reactions. Under preparative conditions, 3-hydroxy-2,5-hexadione, known as Henze's ketol, is formed in high yield and with enantioselectivities up to 88% ee. Furthermore, Henze's ketol is also formed under simulated physiological conditions at micromolar scale, indicating that this reaction might take place in living organisms.


Subject(s)
Acetone/chemistry , Hexanones/chemical synthesis , Pyruvaldehyde/chemistry , Acetoacetates/chemistry , Catalysis , Hexanones/chemistry
10.
Biochem Biophys Res Commun ; 377(3): 1012-7, 2008 Dec 19.
Article in English | MEDLINE | ID: mdl-18977198

ABSTRACT

The differentiation-inducing factor-1 (DIF-1) is a lipophilic signal molecule (chlorinated alkylphenone) that induces stalk cell differentiation in the cellular slime mold Dictyostelium discoideum. In addition, DIF-1 and its derivatives have been shown to possess anti-leukemic activity and glucose consumption-promoting activity in vitro in mammalian cells. In this study, to assess the chemical structure-effect relationship of DIF-1, we synthesized eight derivatives of DIF-1 and investigated their stalk cell-inducing activity in Dictyostelium cells and pharmacological activities in mammalian cells. Of the derivatives, two amide derivatives of DIF-1, whose hydrophobic indexes are close to that of DIF-1, induced stalk cell differentiation as strongly as DIF-1 in Dictyostelium cells. It was also found that some derivatives suppressed cell growth in human K562 leukemia cells and promoted glucose consumption in mouse 3T3-L1 cells. These results give us valuable information as to the chemical structure-effect relationship of DIF-1.


Subject(s)
Hexanones/chemistry , Hexanones/pharmacology , 3T3-L1 Cells , Animals , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Dictyostelium/cytology , Dictyostelium/drug effects , Dictyostelium/metabolism , Glucose/metabolism , Hexanones/chemical synthesis , Hexanones/isolation & purification , Humans , Mice , Structure-Activity Relationship
11.
Chembiochem ; 8(9): 1063-70, 2007 Jun 18.
Article in English | MEDLINE | ID: mdl-17497614

ABSTRACT

Enzymatic carboligation in a solid/gas bioreactor represents a new challenge in biotechnology. In this paper, the continuous gas-phase production of propioin from two propanal molecules by using thiamine diphosphate-dependent enzymes was studied. Two enzymes were used, namely benzaldehyde lyase (BAL) from Pseudomonas fluorescens and benzoylformate decarboxylase (BFD) from Pseudomonas putida. The enzymes are homologous and catalyze carboligase and carbolyase reactions in which no external cofactor regeneration is needed. The influence of water and substrate activity on the initial reaction rate and biocatalyst stability was investigated. An increase in water activity raised the initial reaction rates to the maximal values of 250 and 80 U g(-1) for BAL and BFD, respectively. The half-life showed the same trend with maximal values of 50 and 78 min for BAL and BFD, respectively. The increase in the half-life by increasing water activity was unexpected. It was also observed that BFD is more stable than BAL in the presence of the substrate propanal. Both enzymes showed substrate inhibition in the kinetic studies, and BAL was also deactivated during the reaction. Unexpectedly, the stereoselectivity of both enzymes (ee of 19 % for BAL and racemic mixture for BFD) was significantly impaired in the gas phase compared to the liquid phase.


Subject(s)
Enzymes, Immobilized/chemistry , Hexanones/chemical synthesis , Thiamine Pyrophosphate/chemistry , Aldehyde-Lyases/chemistry , Algorithms , Bioreactors , Carboxy-Lyases/chemistry , Gases , Kinetics , Stereoisomerism , Substrate Specificity , Thermodynamics , Water/chemistry
12.
Biochem Pharmacol ; 70(5): 676-85, 2005 Sep 01.
Article in English | MEDLINE | ID: mdl-16023080

ABSTRACT

The differentiation-inducing factor-1 (DIF-1) is a lipophilic signal molecule (chlorinated alkylphenone) that induces stalk-cell differentiation in the cellular slime mould Dictyostelium discoideum. It has also been shown that DIF-1 and its derivative (DIF-3) suppress cell growth in mammalian tumor cells. In the present study, in order to assess the chemical structure-effect relationship of DIF derivatives and to develop useful agents for the study of both Dictyostelium development and cancer biology, we synthesized 28 analogues of DIF-1 and DIF-3 and investigated their stalk-cell-inducing activity in Dictyostelium HM44 cells (mutant strain) and anti-proliferative activity in human leukemia K562 cells. HM44 cells are defective in endogenous DIF-1 production and should be suitable for the assay for stalk-cell-inducing activity of DIF analogues. DIF-1 and some of its derivatives at nanomolar levels were good stalk-cell inducers in HM44 cells, whereas DIF-3 and some DIF-3 derivatives at micromolar levels were potent anti-proliferative agents in K562 cells. We also tried to search for antagonistic molecules against DIF-1 and DIF-3 but failed to find such molecules from the analogues used here. The present findings would give us hints for identifying the target molecule(s) of DIFs and also for developing novel anti-cancer drugs.


Subject(s)
Antineoplastic Agents/pharmacology , Hexanones/pharmacology , Hydrocarbons, Chlorinated/pharmacology , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Hexanones/chemical synthesis , Humans , Hydrocarbons, Chlorinated/chemical synthesis , K562 Cells , Structure-Activity Relationship
13.
Org Lett ; 5(19): 3375-8, 2003 Sep 18.
Article in English | MEDLINE | ID: mdl-12967278

ABSTRACT

[structure: see text] Non-aldol aldol rearrangement of the epoxy silyl ether 13b afforded the expected anti methyl ketone 14, while the diastereomeric epoxy silyl ether 13a afforded the syn methyl ketone 8b via an unprecedented syn hydride migration. Calculations suggest that this unusual reaction proceeds via the carbocation, which cannot easily rotate due to steric hindrance.


Subject(s)
Aldehydes/chemistry , Epoxy Compounds/chemistry , Ether/chemistry , Hexanones/chemical synthesis , Organosilicon Compounds/chemistry , Molecular Conformation , Molecular Structure , Stereoisomerism
14.
Acta Pol Pharm ; 59(4): 291-3, 2002.
Article in English | MEDLINE | ID: mdl-12403304

ABSTRACT

The derivatives of 3-hydroxyimino-5-methyl-2-hexanone oxime have been obtained in good yield by its reactions either with hydrazine hydrate or phenyl hydrazine, respectively. IR and 1H NMR spectral data of these compounds have been discussed. All the newly synthesised compounds have been tested for their biological activity against S. auerus, S. typhi, C. albicans, A. niger, S. cerevisiae and M. tuberculosis H47RV.


Subject(s)
Anti-Bacterial Agents/chemical synthesis , Hexanones/chemical synthesis , Hydrazones/chemical synthesis , Oximes/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Hexanones/chemistry , Hexanones/pharmacology , Hydrazones/chemistry , Hydrazones/pharmacology , Microbial Sensitivity Tests/methods , Microbial Sensitivity Tests/statistics & numerical data , Oximes/chemistry , Oximes/pharmacology
15.
Acta Pol Pharm ; 59(3): 223-5, 2002.
Article in English | MEDLINE | ID: mdl-12230250

ABSTRACT

A new oxime, 3-hydroxyimino-5-methyl-2-hexanone (HIMH) has been synthesized by the reaction of 1-pentyl nitrite with 5-methyl-2-hexanone under acidic conditions. The subsequent treatment of HIMH with NH2OH x HCl gives 5-methyl-2,3-hexanedione dioxime (H2MHDDO). The structures of these compounds have been confirmed by physicochemical and spectral data. A preliminary screening of these compounds for biological activity against several microorganisms has indicated that they are selective growth inhibitors of m-tuberculosis, in particular.


Subject(s)
Anti-Bacterial Agents/chemical synthesis , Hexanones/chemical synthesis , Oximes/chemical synthesis , Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Negative Bacteria/growth & development , Gram-Positive Bacteria/drug effects , Gram-Positive Bacteria/growth & development , Hexanones/pharmacology , Microbial Sensitivity Tests/statistics & numerical data , Oximes/pharmacology
16.
Chem Res Toxicol ; 14(3): 264-74, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11258975

ABSTRACT

The neurotoxic gamma-diketone, 2,5-hexanedione (2,5-HD), induces neurofilamentous swellings at prenodal sites in proximal axons as a consequence of pyrrolation of lysine epsilon-amino groups on neurofilament proteins. However, there is disagreement as to whether pyrrole formation and the associated alteration of noncovalent interactions is sufficient to cause neurofilament accumulation, or whether pyrrole autoxidation and subsequent protein-protein cross-linking is an obligatory event. To investigate gamma-diketones that might form pyrroles inert to autoxidative-induced cross-linking, we synthesized 1,1,1-trifluoro-2,5-hexanedione, 3-(trifluoromethyl)-2,5-hexanedione (3-TFMHD), and two 3-(dialkylaminocarbonyl)-2,5-diketones and assessed their rates of pyrrole formation with amines, the oxidation susceptibility of the resulting pyrroles, and the protein cross-linking potential in vitro, relative to those of 3-methyl-2,5-hexanedione. 1,1,1-Trifluoro-2,5-hexanedione does not form pyrroles, but the three 2,5-HD analogues with an electron-withdrawing 3-substituent all rapidly formed pyrroles that were inert to autoxidation. Although 3-TMFHD nonetheless still induced cross-linking of ribonuclease A, by a nonoxidative mechanism independent of the pyrrole, the two 3-(dialkylaminocarbonyl)-2,5-diketones did not exhibit any protein cross-linking. As these two gamma-diketones possess aqueous-organic partitioning properties similar to those of 2,5-HD, they should serve as useful mechanistic probes in further studies.


Subject(s)
Cross-Linking Reagents/pharmacology , Hexanones/pharmacology , Neurofilament Proteins/metabolism , Neurotoxins/pharmacology , Pyrroles/pharmacology , Axons/drug effects , Axons/pathology , Hexanones/agonists , Hexanones/chemical synthesis , Oxidation-Reduction , Pyrroles/chemistry
17.
Biochem J ; 306 ( Pt 3): 735-43, 1995 Mar 15.
Article in English | MEDLINE | ID: mdl-7702568

ABSTRACT

Stalk cell differentiation during development of the slime mould Dictyostelium is induced by a chlorinated alkyl phenone called differentiation-inducing factor-1 (DIF-1). Inactivation of DIF-1 is likely to be a key element in the DIF-1 signalling system, and we have shown previously that this is accomplished by a dedicated metabolic pathway involving up to 12 unidentified metabolites. We report here the structure of the first four metabolites produced from DIF-1, as deduced by m.s., n.m.r. and chemical synthesis. The structures of these compounds show that the first step in metabolism is a dechlorination of the phenolic ring, producing DIF metabolite 1 (DM1). DM1 is identical with the previously known minor DIF activity, DIF-3. DIF-3 is then metabolized by three successive oxidations of its aliphatic side chain: a hydroxylation at omega-2 to produce DM2, oxidation of the hydroxy group to a ketone group to produce DM3 and a further hydroxylation at omega-1 to produce DM4, a hydroxyketone of DIF-3. We have investigated the enzymology of DIF-1 metabolism. It is already known that the first step, to produce DIF-3, is catalysed by a novel dechlorinase. The enzyme activity responsible for the first side-chain oxidation (DIF-3 hydroxylase) was detected by incubating [3H]DIF-3 with cell-free extracts and resolving the reaction products by t.l.c. DIF-3 hydroxylase has many of the properties of a cytochrome P-450. It is membrane-bound and uses NADPH as co-substrate. It is also inhibited by CO, the classic cytochrome P-450 inhibitor, and by several other cytochrome P-450 inhibitors, as well as by diphenyliodonium chloride, an inhibitor of cytochrome P-450 reductase. DIF-3 hydroxylase is highly specific for DIF-3: other closely related compounds do not compete for the activity at 100-fold molar excess, with the exception of the DIF-3 analogue lacking the chlorine atom. The Km for DIF-3 of 47 nM is consistent with this enzyme being responsible for DIF-3 metabolism in vivo. The two further oxidations necessary to produce DM4 are also performed in vitro by similar enzyme activities. One of the inhibitors of DIF-3 hydroxylase, ancymidol (IC50 67 nM) is likely to be particularly suitable for probing the function of DIF metabolism during development.


Subject(s)
Dictyostelium/metabolism , Hexanones/metabolism , Animals , Cytochrome P-450 Enzyme System/chemistry , Cytochrome P-450 Enzyme System/isolation & purification , Hexanones/chemical synthesis , Signal Transduction , Subcellular Fractions
18.
Biochem J ; 256(1): 23-8, 1988 Nov 15.
Article in English | MEDLINE | ID: mdl-3223901

ABSTRACT

Previous work has led to the identification of a novel class of effector molecules [DIFs (differentiation-inducing factors) 1-3] released from the slime mould Dictyostelium discoideum. These substances induce stalk-cell differentiation in Dictyostelium discoideum and are thought to act as morphogens in the generation of the prestalk/prespore pattern during development. The DIFs are phenylalkan-1-ones, with chloro, hydroxy and methoxy substitution on the benzene ring. DIFs 1-3 and a number of their analogues have been synthesized by using a simple two-step procedure, and each analogue has been characterized by m.s., u.v. and n.m.r. spectroscopy. The crystal structure of synthetic DIF-1 [1-(3,5-dichloro-2,6-dihydroxy-4-methoxyphenyl)hexan-1-one, was investigated. The specific biological activity of each analogue was determined in a bioassay, where isolated Dictyostelium amoebae are induced to differentiate into stalk cells. The major biologically active substance, DIF-1, caused 50% stalk-cell differentiation at 1.8 x 10(-10) M; the C4 alkyl homologue (DIF-2) and C6 homologue possessed 40 and 16% of the activity of DIF-1 respectively. Further increase or decrease in the alkyl chain length resulted in a marked decrease in specific activity. The pattern of substitution on the benzene ring is a major determinant of bioactivity, since the specific activities of the 2,4-dihydroxy-6-methoxy and trihydroxy analogues were less than 1% of that of DIF-1. Substitution of bromine in DIF-1 had little effect on bioactivity; in contrast the activity of monochloro-DIF-1 (DIF-3) was diminished. There was no evidence for antagonism or synergy between DIF-1 and any of its analogues. This series of analogues will facilitate further studies in the biological effects and mode of action of DIF-1.


Subject(s)
Dictyostelium/metabolism , Hexanones/metabolism , Ketones/metabolism , Pentanones/metabolism , Cell Differentiation , Chromatography, High Pressure Liquid , Hexanones/chemical synthesis , Magnetic Resonance Spectroscopy , Mass Spectrometry , Models, Molecular , Pentanones/chemical synthesis
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