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Szekwan Lam - One of the best experts on this subject based on the ideXlab platform.
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first simultaneous isolation of a ribosome inactivating protein and an antifungal protein from a mushroom lyophyllum shimeji together with evidence for synergism of their antifungal effects
Archives of Biochemistry and Biophysics, 2001Co-Authors: Szekwan LamAbstract:Abstract From the fruiting bodies of the mushroom Lyophyllum shimeji, a novel ribosome inactivating protein with a molecular weight of 20 kDa and exhibiting antifungal activity against Physalospora piricola (IC 50 = 2.5 μM) and Coprinus comatus was isolated. The protein, designated lyophyllin, was purified by ion exchange chromatography on CM–cellulose, affinity chromatography on Affi-gel Blue Gel, and then ion exchange chromatography on Mono S. Lyophyllin possessed an N-terminal sequence with some similarity to those of plant ribosome-inactivating proteins. It inhibited translation in rabbit reticulocyte lysate with an IC 50 of 1 nM, thymidine uptake by murine splenocytes with an IC 50 of 1 μM and HIV-1 reverse transcriptase activity with an IC 50 of 7.9 nM. Lyophyllin did not manifest ribonuclease or hemagglutinating activity. An antifungal protein, designated Lyophyllum antifungal protein (LAP), with a molecular weight of 14 kDa, and an N-terminal sequence somewhat analogous to those of angiosperm thaumatin-like proteins and thaumatins and an inactive variant of the ubiquitin-conjugating enzyme, was first isolated from Lyophyllum shimeji. LAP was adsorbed on CM–cellulose, Affi-gel blue gel, and Mono S. LAP exerted antifungal activity against P. piricola (IC 50 = 70 nM) and Mycosphaerella arachidicola but not against Rhizoctonia solani, Colletotrichum gossypii, and Coprinus comatus. It exerted very low translation inhibitory activity in a rabbit reticulocyte lysate system (IC 50 = 70 μM) and negligible ribonuclease activity toward yeast transfer RNA and hemagglutinating activity toward rabbit erythrocytes. It inhibited HIV-1 reverse transcriptase with an IC 50 of about 5.2 nM. A synergism in antifungal activities of LAP and lyophyllin against P. piricola was demonstrable.
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hypsin a novel thermostable ribosome inactivating protein with antifungal and antiproliferative activities from fruiting bodies of the edible mushroom hypsizigus marmoreus
Biochemical and Biophysical Research Communications, 2001Co-Authors: Szekwan LamAbstract:A novel ribosome-inactivating protein with a molecular weight of 20 kDa was isolated from fruiting bodies of the mushroom Hypsizigus marmoreus. The isolation procedure entailed ion exchange chromatography on CM-cellulose, affinity chromatography on Affi-gel Blue Gel and ion exchange chromatography on Mono Q. The protein designated hypsin demonstrated an inhibitory action against mycelial growth in various fungal species including Mycosphaerella arachidicola, Physalospora piricola, Fusarium oxysporum, and Botrytis cinerea with an IC50 of 2.7, 2.5, 14.2, and 0.06 μM, respectively. Translation in the rabbit reticulocyte lysate system was inhibited with an IC50 of 7 nM and HIV-1 reverse transcriptase activity was inhibited with an IC50 of 8 μM. Antiproliferative activity against mouse leukemia cells and human leukemia and hepatoma cells was observed. About 60% of the translation-inhibitory activity was retained after heating at 100°C for 10 min. No loss of translation-inhibitory activity occurred after brief treatment with trypsin.
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isolation of a novel thermolabile heterodimeric ribonuclease with antifungal and antiproliferative activities from roots of the sanchi ginseng panax notoginseng
Biochemical and Biophysical Research Communications, 2001Co-Authors: Szekwan LamAbstract:An isolation procedure, consisting of ion exchange chromatography on CM-Sepharose, affinity chromatography on Affi-gel blue gel, and fast protein liquid chromatography on Mono S, was utilized to purify a base-nonspecific, heterodimeric ribonuclease (RNase) with diverse activities from roots of the sanchi ginseng Panax notoginseng. The RNase is unique in that it consists of two different nonglycoprotein subunits with a molecular weight of 27 and 29 kDa, respectively. The latter subunit is characterized by an N-terminal sequence showing remarkable similarity to that of the bitter gourd RNase. The Panax notoginseng RNase demonstrates potent RNase and translation-inhibitory activities. In addition, it exhibits antiproliferative activity toward leukemia L1210 cells and antifungal activity against Physalospora piricola and Coprinus comatus. Its RNase activity is not heat-resistant, unlike most RNases which are thermostable.
Zhanyong Guo - One of the best experts on this subject based on the ideXlab platform.
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evaluation of quaternary ammonium chitosan derivatives differing in the length of alkyl side chain synthesis and antifungal activity
International Journal of Biological Macromolecules, 2019Co-Authors: Lijie Wei, Jingjing Zhang, Fang Dong, Zhanyong GuoAbstract:Abstract Chemical modification is one of the prominent methods used to improve the water solubility and bioactivity of chitosan. In this paper, a series of quaternary ammonium chitosan derivatives based on 6-O-chloroacetylated chitosan (CAClC) were successfully designed and synthesized. Detailed structural characterization was carried out by means of FT-IR, 1H NMR spectroscopy, and elemental analysis. Furthermore, the antifungal activity against Botrytis cinerea, Gibberella zeae, and Physalospora piricola Nose was estimated using in vitro hypha measurements. Most of the quaternary ammonium chitosan derivatives showed an inhibitory index of >90% at 1.0 mg/mL and exhibited enhanced antifungal activity when compared to chitosan. On one hand, the higher density of positive charge contributed to the antifungal action. In addition, the inhibitory activity decreased roughly in the order of TriM [(CH3)3] > TriE [(CH2CH3)3] > TriP [(CH2CH2CH3)3] > TriB [(CH2CH2CH2CH3)3]; NNTE [(CH3)2(CH2CH3)] > NNTB [(CH3)2(CH2CH2CH2CH3)] > NNTK [(CH3)2((CH2)9CH3)] at 1.0 mg/mL. The antifungal properties of all the quaternary ammonium chitosan derivatives against the targeted fungi decreased upon increasing the alkyl chain length.
Chunhua Wang - One of the best experts on this subject based on the ideXlab platform.
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synthesis physiochemical property and antimicrobial activity of novel quaternary ammonium salts
Journal of Enzyme Inhibition and Medicinal Chemistry, 2018Co-Authors: Xianrui Xie, Guige Hou, Wei Cong, Feng Zhao, Wenyu Xin, Chunhua WangAbstract:Twenty-four novel 5-phenyl-1,3,4-oxadiazole-2-thiol (POT) analogues, benzo[d]oxazole-2-thiol, benzo[d]thiazole-2-thiol and 5-methyl-1,3,4-thiadiazole-2-thiol-substituted N,N-bis(2-hydroxyethyl) quaternary ammonium salts (QAS) (5a-d, 6a-d, 7a-d, 10a-d, 13a-d, 16a-d) were prepared and characterised by FTIR, NMR and elemental analysis. Part of target compounds (5d, 6d, 7d, 10d, 13d, 16d) displayed potent antimicrobial effect against ten common pathogens (S. aureus, α-H-tococcus, β-H-tococcus, E. coli, P. aeruginosa, Proteus vulgaris, Canidia Albicans, Cytospora mandshurica, Physalospora piricola, Aspergillus niger) and had relatively low cytotoxity against two human cell lines (HaCat and LO2). TEM and SEM images of E. coli and S. aureus morphologies treated with 7d showed that the antibacterial mechanism might be the QAS fixing on cell wall surfaces and puncturing to result in the release of bacterial cytoplasm. This study provides new information of QAS, which could be used to design novel antimicrobial agents applied in clinic or agriculture.
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synthesis characterization and antibacterial properties of dihydroxy quaternary ammonium salts with long chain alkyl bromides
Chemical Biology & Drug Design, 2015Co-Authors: Wenshuai Liu, Chunhua Wang, Jufeng Sun, Guige Hou, Yupeng WangAbstract:Five N-methyl-N-R-N,N-bis(2-hydroxyethyl) ammonium bromides (R = -benzyl (chloride, BNQAS), -dodecyl (C12QAS), -tetradecyl (C14QAS), -hexadecyl (C16QAS), -octadecyl (C18QAS)) were prepared based on N-methyldiethanolamine (MDEA) and halohydrocarbon. Five QAS were characterized by FTIR, NMR, and MS. BNQAS, C12QAS, C14QAS, and C16QAS were confirmed by X-ray single-crystal diffraction. Their antibacterial properties indicated good antibacterial abilities against E. coli, S. aureus, B. subtilis, especially C12QAS with the best antibacterial ability (100% to E. coli, 95.65% to S. aureus, and 91.41% to B. subtilis). In addition, C12QAS also displayed the best antifungal activities than BNQAS and C18QAS against Cytospora mandshurica, Botryosphaeria ribis, Physalospora piricola, and Glomerella cingulata with the ratio of full marks. The strategy provides a facile way to design and develop new types of antibacterial drugs for application in preventing the fruit rot, especially apple.
Lijie Wei - One of the best experts on this subject based on the ideXlab platform.
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evaluation of quaternary ammonium chitosan derivatives differing in the length of alkyl side chain synthesis and antifungal activity
International Journal of Biological Macromolecules, 2019Co-Authors: Lijie Wei, Jingjing Zhang, Fang Dong, Zhanyong GuoAbstract:Abstract Chemical modification is one of the prominent methods used to improve the water solubility and bioactivity of chitosan. In this paper, a series of quaternary ammonium chitosan derivatives based on 6-O-chloroacetylated chitosan (CAClC) were successfully designed and synthesized. Detailed structural characterization was carried out by means of FT-IR, 1H NMR spectroscopy, and elemental analysis. Furthermore, the antifungal activity against Botrytis cinerea, Gibberella zeae, and Physalospora piricola Nose was estimated using in vitro hypha measurements. Most of the quaternary ammonium chitosan derivatives showed an inhibitory index of >90% at 1.0 mg/mL and exhibited enhanced antifungal activity when compared to chitosan. On one hand, the higher density of positive charge contributed to the antifungal action. In addition, the inhibitory activity decreased roughly in the order of TriM [(CH3)3] > TriE [(CH2CH3)3] > TriP [(CH2CH2CH3)3] > TriB [(CH2CH2CH2CH3)3]; NNTE [(CH3)2(CH2CH3)] > NNTB [(CH3)2(CH2CH2CH2CH3)] > NNTK [(CH3)2((CH2)9CH3)] at 1.0 mg/mL. The antifungal properties of all the quaternary ammonium chitosan derivatives against the targeted fungi decreased upon increasing the alkyl chain length.
Hexiang Wang - One of the best experts on this subject based on the ideXlab platform.
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an antifungal peptide from baby lima bean
Applied Microbiology and Biotechnology, 2006Co-Authors: Hexiang WangAbstract:A 6-kDa antifungal peptide with inhibitory activity on mycelial growth in Fusarium oxysporum, Mycosphaerella arachidicola, and Physalospora piricola was isolated from baby lima beans. The peptide suppressed growth in M. arachidicola with an IC50 of 0.87 μM and inhibited activity of HIV-1 reverse transcriptase with an IC50 of 4 μM. The peptide exhibited an N-terminal amino acid sequence similar to those of leguminous defensins. The isolation procedure comprised ion exchange chromatography on diethylaminoethyl (DEAE)-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on carboxymethyl (CM)-cellulose, and gel filtration by fast protein liquid chromatography on Superdex 75. The peptide was unadsorbed on DEAE-cellulose and Affi-gel blue gel but was adsorbed on CM-cellulose.
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ganodermin an antifungal protein from fruiting bodies of the medicinal mushroom ganoderma lucidum
Peptides, 2006Co-Authors: Hexiang WangAbstract:Abstract A 15-kDa antifungal protein, designated ganodermin, was isolated from the medical mushroom Ganoderma lucidum . The isolation procedure utilized chromatography on DEAE-cellulose, Affi-gel blue gel, CM-Sepharose and Superdex 75. Ganodermin was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel and CM-Sepharose. Ganodermin inhibited the mycelial growth of Botrytis cinerea , Fusarium oxysporum and Physalospora piricola with an IC 50 value of 15.2 μM, 12.4 μM and 18.1 μM, respectively. It was devoid of hemagglutinating, deoxyribonuclease, ribonuclease and protease inhibitory activities.
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alveolarin a novel antifungal polypeptide from the wild mushroom polyporus alveolaris
Peptides, 2004Co-Authors: Hexiang Wang, T B NgAbstract:Abstract An antifungal polypeptide, with a molecular mass of 28 kDa as judged by gel filtration and appearing as a single band with a molecular mass of 14 kDa in sodium dodecyl suflate-polyacrylamide gel electrophoresis, was isolated from fresh fruiting bodies of the mushroom Polyporus alveolaris . The antifungal polypeptide, designated as alveolarin, demonstrated an inhibitory action on mycelial growth in Botrytis cinerea , Fusarium oxysporum , Mycosphaerella arachidicola and Physalospora piricola . Alveolarin was isolated with a procedure that entailed ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, and gel filtration on Superdex 75 by fast protein liquid chromatography.
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purification of chrysancorin a novel antifungal protein with mitogenic activity from garland chrysanthemum seeds
Biological Chemistry, 2001Co-Authors: Hexiang WangAbstract:A novel antifungal protein, designated chrysancorin, was isolated from seeds of Chrysanthemum coronarium var. spatiosum with a procedure involving ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue resin, ion exchange chromatography on SP-Sepharose and FPLC-gel filtration on Superdex 75. The N-terminus of chrysancorin displays sequence similarity to the genomic sequence of chromosome 1 from Arabidopsis thaliana BAC T19E23. Chrysancorin exhibits a molecular mass of 13.4 kDa in gel filtration and SDS-polyacrylamide gel electrophoresis. It stimulates the proliferation of mouse splenocytes and inhibits the activity of human immunodeficiency virus-1 reverse transcriptase. The protein possesses antifungal activity against Botrytis cinerea, Mycosphaerella arachidicola and Physalospora piricola, but not against Rhizoctonia solani, Fusarium oxysporum and Coprinus comatus. However, we could not detect antibacterial activity against a variety of bacteria.