Hai Nam - Academia.edu (original) (raw)
Papers by Hai Nam
Bioorganic & Medicinal Chemistry, 2004
Two classes of fluconazole derivatives, (a) carboxylic acid esters and (b) fatty alcohol and carb... more Two classes of fluconazole derivatives, (a) carboxylic acid esters and (b) fatty alcohol and carbohydrate phosphate esters, were synthesized and evaluated in vitro against Cryptococcus neoformans, Candida albicans, and Aspergillus niger. All carboxylic acid ester derivatives of fluconazole (1a-l), such as O-2-bromooctanoylfluconazole (1g, MIC=111 microg/mL) and O-11-bromoundecanoylfluconazole (1j, MIC=198 microg/mL), exhibited higher antifungal activity than fluconazole (MIC > or = 4444 microg/mL) against C. albicans ATCC 14053 in SDB medium. Several fatty alcohol phosphate triester derivatives of fluconazole, such as 2a, 2b, 2f, 2g, and 2h, exhibited enhanced antifungal activities against C. albicans and/or A. niger compared to fluconazole in SDB medium. For example, 2-cyanoethyl-omega-undecylenyl fluconazole phosphate (2b) with MIC value of 122 microg/mL had at least 36 times greater antifungal activity than fluconazole against C. albicans in SDB medium. Methyl-undecanyl fluconazole phosphate (2f) with a MIC value of 190 microg/mL was at least 3-fold more potent than fluconazole against A. niger ATCC 16404. All compounds had higher estimated lipophilicity and dermal permeability than those for fluconazole. These results demonstrate the potential of these antifungal agents for further development as sustained-release topical antifungal chemotherapeutic agents.
Bioorganic & Medicinal Chemistry Letters, 2001
A series of 3-aryl-2-propenoates including cinnamates, (E)-methyl/ethyl 3-[2-(1,4-dimethoxy-5,8-d... more A series of 3-aryl-2-propenoates including cinnamates, (E)-methyl/ethyl 3-[2-(1,4-dimethoxy-5,8-dione)naphthalenyl]-2-propenoates (8ba, 8bb) and (E)-methyl/ethyl 3-[2-(1,4-dihydroxy-9,10-dione)anthracenyl]-2-propenoates (9aa,9ab) was synthesized and evaluated for antitumor cytotoxicity. It was found that the ortho- or para-dihydroxy funtionality on the aryl ring was essential for the cytotoxicity of cinnamates. Compounds 8ba, 8bb and 9aa, 9ab showed potent cytotoxicity against various tumor cell lines.
International Journal of Refrigeration-revue Internationale Du Froid, 2002
A drop-in test of a mixed refrigerant R407C is performed in a commercial screw chiller with shell... more A drop-in test of a mixed refrigerant R407C is performed in a commercial screw chiller with shell-and-tube heat exchangers originally designed for R22. The test results show a severe performance reduction when substituting the refrigerant from R22 to R407C. The reason for the performance reduction is analyzed comprehensively, and the influence of thermodynamic properties, compressor efficiency, and heat transfer is evaluated quantitatively. The major factor causing the performance reduction is assessed as the degradation of the heat transfer in using the mixed refrigerant, R407C. The heat transfer degradation in the evaporator is found to be larger and influences more on the chiller performance reduction. The performance reduction caused by the evaporator is approximately two times compared with that of the condenser. # Etude expe´rimentale sur la performance de R407C pour remplacer le R22 dans un refroidisseur a`vis muni d'e´changeurs tubulaires
Journal of Alloys and Compounds, 2005
A fine-grained AZ91 alloy was prepared by equal channel angular pressing (ECAP). The evolution of... more A fine-grained AZ91 alloy was prepared by equal channel angular pressing (ECAP). The evolution of the microstructure and the deformation behavior were investigated as a function of the number of ECAP passes. At room temperature the tensile strength of the ECA pressed specimens is higher than that of the initial state due to the grain refinement and the increase of the dislocation density during ECAP. Above 200 • C the ductility increases due to the increase of the relative fraction of c + a dislocations and also owing to the breakage of the rod-like Al 12 Mg 17 precipitates during ECAP processing.
Bioorganic & Medicinal Chemistry, 2004
Two classes of fluconazole derivatives, (a) carboxylic acid esters and (b) fatty alcohol and carb... more Two classes of fluconazole derivatives, (a) carboxylic acid esters and (b) fatty alcohol and carbohydrate phosphate esters, were synthesized and evaluated in vitro against Cryptococcus neoformans, Candida albicans, and Aspergillus niger. All carboxylic acid ester derivatives of fluconazole (1a-l), such as O-2-bromooctanoylfluconazole (1g, MIC=111 microg/mL) and O-11-bromoundecanoylfluconazole (1j, MIC=198 microg/mL), exhibited higher antifungal activity than fluconazole (MIC > or = 4444 microg/mL) against C. albicans ATCC 14053 in SDB medium. Several fatty alcohol phosphate triester derivatives of fluconazole, such as 2a, 2b, 2f, 2g, and 2h, exhibited enhanced antifungal activities against C. albicans and/or A. niger compared to fluconazole in SDB medium. For example, 2-cyanoethyl-omega-undecylenyl fluconazole phosphate (2b) with MIC value of 122 microg/mL had at least 36 times greater antifungal activity than fluconazole against C. albicans in SDB medium. Methyl-undecanyl fluconazole phosphate (2f) with a MIC value of 190 microg/mL was at least 3-fold more potent than fluconazole against A. niger ATCC 16404. All compounds had higher estimated lipophilicity and dermal permeability than those for fluconazole. These results demonstrate the potential of these antifungal agents for further development as sustained-release topical antifungal chemotherapeutic agents.
Bioorganic & Medicinal Chemistry Letters, 2001
A series of 3-aryl-2-propenoates including cinnamates, (E)-methyl/ethyl 3-[2-(1,4-dimethoxy-5,8-d... more A series of 3-aryl-2-propenoates including cinnamates, (E)-methyl/ethyl 3-[2-(1,4-dimethoxy-5,8-dione)naphthalenyl]-2-propenoates (8ba, 8bb) and (E)-methyl/ethyl 3-[2-(1,4-dihydroxy-9,10-dione)anthracenyl]-2-propenoates (9aa,9ab) was synthesized and evaluated for antitumor cytotoxicity. It was found that the ortho- or para-dihydroxy funtionality on the aryl ring was essential for the cytotoxicity of cinnamates. Compounds 8ba, 8bb and 9aa, 9ab showed potent cytotoxicity against various tumor cell lines.
International Journal of Refrigeration-revue Internationale Du Froid, 2002
A drop-in test of a mixed refrigerant R407C is performed in a commercial screw chiller with shell... more A drop-in test of a mixed refrigerant R407C is performed in a commercial screw chiller with shell-and-tube heat exchangers originally designed for R22. The test results show a severe performance reduction when substituting the refrigerant from R22 to R407C. The reason for the performance reduction is analyzed comprehensively, and the influence of thermodynamic properties, compressor efficiency, and heat transfer is evaluated quantitatively. The major factor causing the performance reduction is assessed as the degradation of the heat transfer in using the mixed refrigerant, R407C. The heat transfer degradation in the evaporator is found to be larger and influences more on the chiller performance reduction. The performance reduction caused by the evaporator is approximately two times compared with that of the condenser. # Etude expe´rimentale sur la performance de R407C pour remplacer le R22 dans un refroidisseur a`vis muni d'e´changeurs tubulaires
Journal of Alloys and Compounds, 2005
A fine-grained AZ91 alloy was prepared by equal channel angular pressing (ECAP). The evolution of... more A fine-grained AZ91 alloy was prepared by equal channel angular pressing (ECAP). The evolution of the microstructure and the deformation behavior were investigated as a function of the number of ECAP passes. At room temperature the tensile strength of the ECA pressed specimens is higher than that of the initial state due to the grain refinement and the increase of the dislocation density during ECAP. Above 200 • C the ductility increases due to the increase of the relative fraction of c + a dislocations and also owing to the breakage of the rod-like Al 12 Mg 17 precipitates during ECAP processing.