MyMedR

Total syntheses of Prelactone V and Prelactone B

Raghavendra S, Tadiparthi K, Yadav JS

Carbohydr Res, 2017 Apr 10;442:17-19.

PMID: 28282511 DOI: 10.1016/j.carres.2017.02.008

The total syntheses of natural products Prelactone-V and Prelactone-B have been accomplished by a novel Chiron approach starting from d-glucose. The synthesis involves isopropylidene acetal formation of d-glucose using Poly(4-vinylpyridine) supported iodine as a catalyst, Tebbe olefination, Grignard reaction, Wittig olefination, selective mono deprotection of acetal using PMA/SiO2, hydrogenation and anti-1,3-diol formation are as key steps.

Matched MeSH terms: Lactones/chemical synthesis*; Lactones/chemistry

Fulltext Complete genome sequence of Burkholderia sp. Strain GG4, a betaproteobacterium that reduces 3-oxo-N-acylhomoserine lactones and produces different N-acylhomoserine lactones

Hong KW, Koh CL, Sam CK, Yin WF, Chan KG

J Bacteriol, 2012 Nov;194(22):6317.

PMID: 23105060 DOI: 10.1128/JB.01578-12

Burkholderia sp. strain GG4, isolated from the ginger rhizosphere, possesses a unique N-acylhomoserine lactone (AHL)-modifying activity that reduces 3-oxo-AHLs to 3-hydroxy-AHLs. To the best of our knowledge, this is the first sequenced genome from a bacterium of the genus Burkholderia that shows both quorum-sensing and signaling confusion activities.

Matched MeSH terms: Lactones/metabolism*; Lactones/chemistry*

Fulltext Whole-Genome Sequencing Analysis of Quorum-Sensing Aeromonas hydrophila Strain M023 from Freshwater

Tan WS, Yin WF, Chang CY, Chan KG

Genome Announc, 2015;3(1).

PMID: 25700404 DOI: 10.1128/genomeA.01548-14

Aeromonas hydrophila is a well-known waterborne pathogen that recently was found to infect humans. Here, we report the draft genome of a freshwater isolate from a Malaysian waterfall, A. hydrophila strain M023, which portrays N-acylhomoserine lactone-dependent quorum sensing.

Matched MeSH terms: Lactones

Fulltext Genomic Insights of Pectobacterium carotovorum Strain M022 Quorum-Sensing Activity through Whole-Genome Sequencing

Chan KG, Tan WS

Genome Announc, 2015;3(1).

PMID: 25676763 DOI: 10.1128/genomeA.01554-14

Pectobacterium carotovorum is known to cause serious damage to various major crops worldwide. Here, we report the draft genome of Pectobacterium carotovorum strain M022, a freshwater isolate from a Malaysian waterfall, which has been reported as a plant pathogen and is able to communicate with N-acylhomoserine lactone-mediated quorum sensing.

Matched MeSH terms: Lactones

Fulltext Quorum sensing activity in Pandoraea pnomenusa RB38

Ee R, Lim YL, Kin LX, Yin WF, Chan KG

Sensors (Basel), 2014;14(6):10177-86.

PMID: 24919016 DOI: 10.3390/s140610177

Strain RB38 was recovered from a former dumping area in Malaysia. MALDI-TOF mass spectrometry and genomic analysis identified strain RB-38 as Pandoraea pnomenusa. Various biosensors confirmed its quorum sensing properties. High resolution triple quadrupole liquid chromatography-mass spectrometry analysis was subsequently used to characterize the N-acyl homoserine lactone production profile of P. pnomenusa strain RB38, which validated that this isolate produced N-octanoyl homoserine lactone as a quorum sensing molecule. This is the first report of the production of N-octanoyl homoserine lactone by P. pnomenusa strain RB38.

Matched MeSH terms: Lactones/analysis; Lactones/metabolism; Lactones/chemistry

New flavan and alkyl alpha,beta-lactones from the stem bark of Horsfieldia superba

Al-Mekhlafi NA, Shaaria K, Abas F, Jeyaraj EJ, Stanslas J, Khalivulla SI, et al.

Nat Prod Commun, 2013 Apr;8(4):447-51.

PMID: 23738449

In the present study phytochemical investigation of the methanol extract of the stem bark of Horsfieldia superba led to the isolation of twenty compounds (1-20), of which three (1-3) were new. However, compounds 2 and 3 were previously reported as synthetic alpha,beta-lactones. The compounds were characterized as (-)-3,4',7-trihydroxy-3'-methoxyflavan (1), (-)-5,6-dihydro-6-undecyl-2H-pyran-2-one (2), and (-)-5,6-dihydro-6-tridecyl-2H-pyran-2-one (3). Seventeen other known compounds were also isolated and identified as (-)-viridiflorol (4), hexacosanoic acid (5), beta-sitosterol (6), methyl 2,4-dihydroxy-6-methylbenzoate (methylorsellinate) (7), methyl 2,4-dihydroxy-3,6-dimethylbenzoate (8), (-)-4'-hydroxy-7-methoxyflavan (9), (-)-4',7-dihydroxyflavan (10), (-)-4',7-dihydroxy-3'-methoxyflavan (11), (+)-3,4',7-trihydroxyflavan (12), (-)-catechin (13), (-)-epicatechin (14), (-)-7-hydroxy-3',4'-methylenedioxyflavan (15), 2',3,4-trihydroxy-4'-methoxydihydrochalcone (16), 3',4',7-trihydroxyflavone (17), (+)-4'-hydroxy-7-methoxyflavanone (18), hexadecanoic acid (palmitic acid) (19) and 3,4-dihydroxybenzoic acid (20). The structures of the compounds were fully characterized by various physical methods (melting point, optical rotation), spectral (UV, IR, ID and 2D NMR) and mass spectrometric techniques. In vitro assay of compounds 2 and 3 demonstrated moderate cytotoxic activities against human prostate (PC-3), colon (HCT-116) and breast (MCF-7) cancer cells, while the chloroform and ethyl acetate fractions of H. superba were found to exhibit moderate AChE inhibitory activity (IC50 72 and 60 microg/mL).

Matched MeSH terms: Lactones/isolation & purification*; Lactones/pharmacology; Lactones/chemistry

Cytotoxic prenylated depsidones from Garcinia parvifolia

Xu YJ, Chiang PY, Lai YH, Vittal JJ, Wu XH, Tan BK, et al.

J Nat Prod, 2000 Oct;63(10):1361-3.

PMID: 11076552

Leaf extracts of Garcinia parvifolia provided relatively high yields of four novel, cytotoxic prenylated depsidones. The structures were determined mainly by detailed NMR spectral analysis and X-ray crystallography.

Matched MeSH terms: Lactones/isolation & purification; Lactones/pharmacology*; Lactones/chemistry

Goniolanceolatins A-H, Cytotoxic Bis-styryllactones from Goniothalamus lanceolatus

Bihud NV, Rasol NE, Imran S, Awang K, Ahmad FB, Mai CW, et al.

J Nat Prod, 2019 09 27;82(9):2430-2442.

PMID: 31433181 DOI: 10.1021/acs.jnatprod.8b01067

Eight new bis-styryllactones, goniolanceolatins A-H (1-8), possessing a rare α,β-unsaturated δ-lactone moiety with a (6S)-configuration, were isolated from the CH2Cl2 extract of the stembark and roots of Goniothalamus lanceolatus Miq., a plant endemic to Malaysia. Absolute structures were established through extensive 1D- and 2D-NMR data analysis, in combination with electronic dichroism (ECD) data. All of the isolates were evaluated for their cytotoxicity against human lung and colorectal cancer cell lines. Compounds 2 and 4 showed cytotoxicity, with IC50 values ranging from 2.3 to 4.2 μM, and were inactive toward human noncancerous lung and colorectal cells. Compounds 1, 3, 6, 7, and 8 showed moderate to weak cytotoxicity. Docking studies of compounds 2 and 4 showed that they bind with EGFR tyrosine kinase and cyclin-dependent kinase 2 through hydrogen bonding interactions with the important amino acids, including Lys721, Met769, Asn818, Arg157, Ile10, and Glu12.

Matched MeSH terms: Lactones/isolation & purification; Lactones/pharmacology*; Lactones/chemistry

Furanoditerpenes of Fibraurea chloroleuca

Zakaria MB, Saito I, Yao XK, Wang RJ, Matsuura T

Planta Med, 1989 Oct;55(5):477-8.

PMID: 17262463

Fibraurin, chasmanthin, and palmarin were isolated from the stems of FIBRAUREA CHLOROLEUCA, Fam. Menispermaceae. The structure of the minor constituent, palmarin, was determined by X-ray crystallographic analysis.

Matched MeSH terms: Lactones

Fulltext Degradation of bacterial quorum sensing signaling molecules by the microscopic yeast Trichosporon loubieri isolated from tropical wetland waters

Wong CS, Koh CL, Sam CK, Chen JW, Chong YM, Yin WF, et al.

Sensors (Basel), 2013;13(10):12943-57.

PMID: 24072030 DOI: 10.3390/s131012943

Proteobacteria produce N-acylhomoserine lactones as signaling molecules, which will bind to their cognate receptor and activate quorum sensing-mediated phenotypes in a population-dependent manner. Although quorum sensing signaling molecules can be degraded by bacteria or fungi, there is no reported work on the degradation of such molecules by basidiomycetous yeast. By using a minimal growth medium containing N-3-oxohexanoylhomoserine lactone as the sole source of carbon, a wetland water sample from Malaysia was enriched for microbial strains that can degrade N-acylhomoserine lactones, and consequently, a basidiomycetous yeast strain WW1C was isolated. Morphological phenotype and molecular analyses confirmed that WW1C was a strain of Trichosporon loubieri. We showed that WW1C degraded AHLs with N-acyl side chains ranging from 4 to 10 carbons in length, with or without oxo group substitutions at the C3 position. Re-lactonisation bioassays revealed that WW1C degraded AHLs via a lactonase activity. To the best of our knowledge, this is the first report of degradation of N-acyl-homoserine lactones and utilization of N-3-oxohexanoylhomoserine as carbon and nitrogen source for growth by basidiomycetous yeast from tropical wetland water; and the degradation of bacterial quorum sensing molecules by an eukaryotic yeast.

Matched MeSH terms: Lactones/metabolism*

Studies on the microbial synthesis and characterization of polyhydroxyalkanoates containing 4-hydroxyvalerate using γ-valerolactone

Muzaiyanah AR, Amirul AA

Appl Biochem Biotechnol, 2013 Jul;170(5):1194-215.

PMID: 23649305 DOI: 10.1007/s12010-013-0247-6

In this study, the ability of Cupriavidus sp. USMAA2-4 to synthesize polyhydroxyalkanoates (PHA) containing 4-hydroxyvalerate monomer (4HV) was studied through one-stage cultivation using γ-valerolactone as the carbon precursor. The presence of 4HV monomer unit in the polymer was detected through gas chromatography analysis, proving the capability of this wild strain bacterium to produce poly(3-hydrxybutyrate-co-3-hydroxyvalerate-co-4-hydroxyvalerate) [P(3HB-co-3HV-co-4HV)] terpolymer. Existence of a 4HV monomer unit in the PHA produced was further confirmed through (13)C and (1)H NMR analysis. P(3HB-co-88 % 3HV-co-1 % 4HV) terpolymer with the highest PHA content of 63 wt% was obtained through combination of 0.14 wt% C of γ-valerolactone with 0.42 wt% C of oleic acid. Various compositions of P(3HB-co-3HV-co-4HV) terpolymer with 3HV and 4HV compositions ranging from 11 to 94 mol% and from 1 to 4 mol%, respectively, were acquired by manipulating γ-valerolactone and oleic acid concentrations. The molecular weight and the thermal and mechanical properties of four different compositions of terpolymers-P(3HB-co-91 % 3HV-co-1 % 4HV), P(3HB-co-55 % 3HV-co-2 % 4HV), P(3HB-co-27 % 3HV-co-2 % 4HV), and P(3HB-co-9 % 3HV-co-1 % 4HV)-were characterized. Among these terpolymers, P(3HB-co-27 % 3HV-co-2 % 4HV) terpolymer with a molecular weight of 5.7 (10(5) Da) exhibited the highest elongation to break (264 %). The monomer unit compositional distributions of these terpolymers were investigated through acetone-water fractionation analysis. The results suggested that these produced terpolymers had broad 3HV compositional distribution and narrow 4HV compositional distribution.

Matched MeSH terms: Lactones/metabolism*

Fulltext Whole-genome sequence of N-acylhomoserine lactone-synthesizing and -degrading Acinetobacter sp. strain GG2

Hong KW, Koh CL, Sam CK, Yin WF, Chan KG

J Bacteriol, 2012 Nov;194(22):6318.

PMID: 23105061 DOI: 10.1128/JB.01579-12

Acinetobacter sp. strain GG2 is a quorum-sensing and quorum-quenching bacterium isolated from the ginger rhizosphere. It degrades a broad range of N-acylhomoserine lactone molecules via lactonase. The genome sequence of strain GG2 may provide insights on the regulation of quorum-sensing and quorum-quenching mechanisms in this bacterium.

Matched MeSH terms: Lactones/metabolism*

Fulltext Whole-Genome Analysis of Aeromonas hydrophila Strain 187, Exhibiting Quorum-Sensing Activity

Chan XY, Chua KH, Yin WF, Puthucheary SD, Chan KG

Genome Announc, 2014;2(6).

PMID: 25540357 DOI: 10.1128/genomeA.01360-14

Aeromonas hydrophila is a quorum-sensing (QS) bacterium that causes diarrhea in humans upon infection. Here, we report the genome of pathogenic Aeromonas hydrophila strain 187, which possesses a QS gene responsible for signaling molecule N-acyl homoserine lactone (AHL) synthesis and has been found to be located at contig 36.

Matched MeSH terms: Lactones

Fulltext Genome Sequence Analysis Reveals Evidence of Quorum-Sensing Genes Present in Aeromonas hydrophila Strain M062, Isolated from Freshwater

Chan KG, Tan WS, Chang CY, Yin WF, Mumahad Yunos NY

Genome Announc, 2015;3(2).

PMID: 25767237 DOI: 10.1128/genomeA.00100-15

Aeromonas hydrophila has emerged worldwide as a human pathogen. Here, we report the draft whole-genome sequence of a freshwater isolate from Malaysia, A. hydrophila strain M062, and its N-acylhomoserine lactone genes are also reported here.

Matched MeSH terms: Lactones

Fulltext Draft Genome Perspective of Staphylococcus saprophyticus Strain SU8, an N-Acyl Homoserine Lactone-Degrading Bacterium

Chan KG, Sulaiman J, Yong DA, Tee KK, Yin WF, Priya K

Genome Announc, 2015;3(5).

PMID: 26404582 DOI: 10.1128/genomeA.01097-15

Staphylococcus saprophyticus strain SU8 was isolated from a pristine water source in Malaysia and it exhibited degradation of N-hexanoylhomoserine lactone. Here we report the draft genome sequence of S. saprophyticus strain SU8 to further understand its quorum quenching abilities.

Matched MeSH terms: Lactones

Fulltext Draft Genome Sequence of Jeotgalibacillus soli DSM 23228, a Bacterium Isolated from Alkaline Sandy Soil

Goh KM, Chan KG, Yaakop AS, Chan CS, Ee R, Tan WS, et al.

Genome Announc, 2015;3(3).

PMID: 25999554 DOI: 10.1128/genomeA.00512-15

Jeotgalibacillus soli, a bacterium capable of degrading N-acyl homoserine lactone, was isolated from a soil sample in Portugal. J. soli constitutes the only Jeotgalibacillus species isolated from a non-marine source. Here, the draft genome, several interesting glycosyl hydrolases, and its putative N-acyl homoserine lactonases are presented.

Matched MeSH terms: Lactones

Antifungal garcinia acid esters from the fruits of Garcinia atroviridis

Mackeen MM, Ali AM, Lajis NH, Kawazu K, Kikuzaki H, Nakatani N

Z Naturforsch C J Biosci, 2002 6 18;57(3-4):291-5.

PMID: 12064729

Two new garcinia acid derivatives, 2-(butoxycarbonylmethyl)-3-butoxycarbonyl-2-hydroxy-3-propanolide and 1',1"-dibutyl methyl hydroxycitrate, were isolated from the fruits of Garcinia atroviridis guided by TLC bioautography against the fungus Cladosporium herbarum. The structures of these compounds were established by spectral analysis. The former compound represents a unique beta-lactone structure and the latter compound is most likely an artefact of garcinia acid (= hydroxycitric acid). Both compounds showed selective antifungal activity comparable to that of cycloheximide (MID: 0.5 microg/spot) only against C herbarum at the MIDs of 0.4 and 0.8 microg/spot but were inactive against bacteria (Bacillus subtilis, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli), other fungi (Alternaria sp., Fusarium moniliforme and Aspergillus ochraceous) including the yeast Candida albicans.

Matched MeSH terms: Lactones/isolation & purification; Lactones/pharmacology; Lactones/chemistry*

Fulltext Pharmaceutical quality of nine generic orlistat products compared with Xenical(r)

Taylor PW, Arnet I, Fischer A, Simpson IN

Obes Facts, 2010 Aug;3(4):231-7.

PMID: 20823686 DOI: 10.1159/000319450

OBJECTIVE: To compare the pharmaceutical quality of Xenical (chemically produced orlistat) with nine generic products, each produced by fermentation processes.

METHODS: Xenical 120 mg capsules (Roche, Basel, Switzerland) were used as reference material. Generic products were from India, Malaysia, Argentina, Philippines, Uruguay, and Taiwan. Colour, melting temperature, crystalline form, particle size, capsule fill mass, active pharmaceutical ingredient content, amount of impurities, and dissolution were compared. Standard physical and chemical laboratory tests were those developed by Roche for Xenical.

RESULTS: All nine generic products failed the Xenical specifications in four or more tests, and two generic products failed in seven tests. A failure common to all generic products was the amount of impurities present, mostly due to different by-products, including side-chain homologues not present in Xenical. Some impurities were unidentified. Two generic products tested failed the dissolution test, one product formed a capsule-shaped agglomerate on storage and resulted in poor (=15%) dissolution. Six generic products were powder formulations.

CONCLUSIONS: All tested generic orlistat products were pharmaceutically inferior to Xenical. The high levels of impurities in generic orlistat products are a major safety and tolerability concern.

Matched MeSH terms: Lactones/standards*; Lactones/chemistry

One-pot lipase-catalyzed esterification of ε-caprolactone with methyl-d-glucopyranoside and its elongation with free 6-hydroxyhexanoate monomer units

Saat MN, Mohamad Annuar MS

Biotechnol Appl Biochem, 2020 May;67(3):354-365.

PMID: 31746015 DOI: 10.1002/bab.1859

One-pot synthesis of sugar-functionalized oligomeric caprolactone was carried out by lipase-catalyzed esterification of ε-caprolactone (ECL) with methyl-d-glucopyranoside (MGP) followed by the elongation of functionalized oligomer chain. Functionalization was performed in a custom-fabricated glass reactor equipped with Rushton turbine impeller and controlled temperature at 60 °C using tert-butanol as reaction medium. The overall reaction steps include MGP esterification of ECL monomer and its subsequent elongation by free 6-hydroxyhexanoate monomer units. A ping-pong bi-bi mechanism without ternary complex was proposed for esterification of ECL and MGP with apparent values of kinetic constant, namely maximal velocity (Vmax ), Michaelis constant for MGP (KmMGP ), and Michaelis constant for ECL (KmECL ) at 3.848 × 10-3 M H-1 , 8.189 × 10-2 M, and 6.050 M, respectively. Chain propagation step of MGP-functionalized ECL oligomer exhibits the properties of living polymerization mechanism. Linear relationship between conversion (%) and number average molecular weight, Mn (g mol-1 ), of functionalized oligomer was observed. Synthesized functionalized oligomer showed narrow range of molecular weight from 1,400 to 1,600 g mol-1 with more than 90% conversion achieved. Structural analysis confirmed the presence of covalent bond between the hydroxyl group in MGP with carboxyl end group of ECL oligomer.

Matched MeSH terms: Lactones/metabolism*; Lactones/chemistry

Fulltext Genome sequence of Dyella japonica strain A8, a quorum-quenching bacterium that degrades N-acylhomoserine lactones, isolated from Malaysian tropical soil

Chen JW, Chan KG

J Bacteriol, 2012 Nov;194(22):6331.

PMID: 23105069 DOI: 10.1128/JB.01637-12

Dyella japonica strain A8 is a Malaysian tropical soil bacterial strain which shows N-acylhomoserine lactone-degrading activity. Here, we present its draft genome sequence. A putative quorum-quenching gene was identified based on the genome sequence analysis of strain A8. To the best of our knowledge, this is the first genome announcement of a member from the genus of Dyella, and this is also the first work that reports the quorum-quenching activity of Dyella japonica.

Matched MeSH terms: Lactones/metabolism*; Lactones/chemistry

Displaying publications 1 - 20 of 87 in total