The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
M. I. Choudhary - One of the best experts on this subject based on the ideXlab platform.
-
tyrosinase inhibitory lignans from the methanol extract of the roots of vitex negundo linn and their structure activity relationship
Phytomedicine, 2006Co-Authors: Abdul Malik, Aqeel Ahmad, Mahmud Tareq Hassan Khan, Sher Bahadar Khan, M. I. ChoudharyAbstract:Abstract Phytochemical investigation of the methanol extract of Vitex negundo afforded eight lignans; negundin A 1 , negundin B 2 , 6-hydroxy-4-(4-hydroxy-3-methoxy)-3-hydroxymethyl-7-methoxy-3,4-dihydro-2-naphthaledehyde 3 , vitrofolal E 4 , (+)-lyoniresinol 5 , (+)-lyoniresinol-3 α - O - β - d -glucoside 6 , (+)-(−)-pinoresinol 7 , and (+)-diasyringaresinol 8 . The structures of these compounds were elucidated unambiguously by spectroscopic methods including 1D and 2D NMR analysis and also by comparing experimental data with literature data. The tyrosinase inhibitory potency of these compounds has been evaluated and attempts to justify their structure–activity relationships have been made in the present work. The compound 5 was found to be the most potent (IC 50 =3.21 μM) while other compounds demonstrated moderate to potent inhibitions. It was found that the substitution of functional group(s) at C-2 and C-3 positions and the presence of the –CH 2 OH group plays a vital role in the potency of the compounds. The compound 5 can act as a potential lead molecule to develop new drugs for the treatment of hyperpigmentation associated with the high production of melanocytes.
-
tyrosinase inhibitory lignans from the methanol extract of the roots of vitex negundo linn and their structure activity relationship
Phytomedicine, 2006Co-Authors: Abdul Malik, Aqeel Ahmad, Mahmud Tareq Hassan Khan, Sher Bahadar Khan, M. I. ChoudharyAbstract:Phytochemical investigation of the methanol extract of Vitex negundo afforded eight lignans; negundin A 1, negundin B 2, 6-hydroxy-4-(4-hydroxy-3-methoxy)-3-hydroxymethyl-7-methoxy-3,4-dihydro-2-naphthaledehyde 3, vitrofolal E 4, (+)-lyoniresinol 5, (+)-lyoniresinol-3alpha-O-beta-d-glucoside 6, (+)-(-)-pinoresinol 7, and (+)-diasyringaresinol 8. The structures of these compounds were elucidated unambiguously by spectroscopic methods including 1D and 2D NMR analysis and also by comparing experimental data with literature data. The tyrosinase inhibitory potency of these compounds has been evaluated and attempts to justify their structure-activity relationships have been made in the present work. The compound 5 was found to be the most potent (IC(50)=3.21 microM) while other compounds demonstrated moderate to potent inhibitions. It was found that the substitution of functional group(s) at C-2 and C-3 positions and the presence of the -CH(2)OH group plays a vital role in the potency of the compounds. The compound 5 can act as a potential lead molecule to develop new drugs for the treatment of hyperpigmentation associated with the high production of melanocytes.
Laiwan Foong - One of the best experts on this subject based on the ideXlab platform.
-
inner coordination sphere tin iv complexes with some o n n terdentate n 2 hydroxybenzaldehyde 1 amino 2 phenyleneimine and n 2 hydroxy 1 naphthaldehyde 1 amino 2 phenyleneimine and o n n o quadridentate n n bis 2 hydroxybenzaldehyde 1 2 phenylenediim
Polyhedron, 1997Co-Authors: Siangguan Teoh, Guan-yeow Yeap, Laiwan FoongAbstract:From the reactions of SnCl 4 with organotin(IV) chlorides (RSnCl 3 , R 2 SnCl 2 and R 3 SnCl, where R = Bu, Me and Ph) with N -(2-hydroxybenzaldehyde)-1-amino-2-phenyleneimine, N -(2-hydroxyl-1-naphthaldehyde)-1-amino-2-phenyleneimine, N , N ′-bis(2-hydroxybenzaldehyde)-1,2-phenylenediimine and N , N ′-bis(2-hydroxy-1-naphthaldehyde)-1,2-phenylenediimine a series of complexes have been synthesized and characterized, respectively, by microanalytical, IR, and 1 H NMR spectroscopic methods. The Ph 2 SnCl 2 reacted with N -(2-hydroxy-1-naphthaldehyde)-1-amino-2-phenyleneimine giving Ph 2 Sn(NAPPDI) [where NAPPDI = deprotonated N , N ′-bis(2-hydroxy-1-naphthaldehyde)-1,2-phenylenediimine], wherein the former Schiff base exhibit a facile intramolecular CN bond cleavage and intermolecular CN bond formation.
Abdul Malik - One of the best experts on this subject based on the ideXlab platform.
-
tyrosinase inhibitory lignans from the methanol extract of the roots of vitex negundo linn and their structure activity relationship
Phytomedicine, 2006Co-Authors: Abdul Malik, Aqeel Ahmad, Mahmud Tareq Hassan Khan, Sher Bahadar Khan, M. I. ChoudharyAbstract:Abstract Phytochemical investigation of the methanol extract of Vitex negundo afforded eight lignans; negundin A 1 , negundin B 2 , 6-hydroxy-4-(4-hydroxy-3-methoxy)-3-hydroxymethyl-7-methoxy-3,4-dihydro-2-naphthaledehyde 3 , vitrofolal E 4 , (+)-lyoniresinol 5 , (+)-lyoniresinol-3 α - O - β - d -glucoside 6 , (+)-(−)-pinoresinol 7 , and (+)-diasyringaresinol 8 . The structures of these compounds were elucidated unambiguously by spectroscopic methods including 1D and 2D NMR analysis and also by comparing experimental data with literature data. The tyrosinase inhibitory potency of these compounds has been evaluated and attempts to justify their structure–activity relationships have been made in the present work. The compound 5 was found to be the most potent (IC 50 =3.21 μM) while other compounds demonstrated moderate to potent inhibitions. It was found that the substitution of functional group(s) at C-2 and C-3 positions and the presence of the –CH 2 OH group plays a vital role in the potency of the compounds. The compound 5 can act as a potential lead molecule to develop new drugs for the treatment of hyperpigmentation associated with the high production of melanocytes.
-
tyrosinase inhibitory lignans from the methanol extract of the roots of vitex negundo linn and their structure activity relationship
Phytomedicine, 2006Co-Authors: Abdul Malik, Aqeel Ahmad, Mahmud Tareq Hassan Khan, Sher Bahadar Khan, M. I. ChoudharyAbstract:Phytochemical investigation of the methanol extract of Vitex negundo afforded eight lignans; negundin A 1, negundin B 2, 6-hydroxy-4-(4-hydroxy-3-methoxy)-3-hydroxymethyl-7-methoxy-3,4-dihydro-2-naphthaledehyde 3, vitrofolal E 4, (+)-lyoniresinol 5, (+)-lyoniresinol-3alpha-O-beta-d-glucoside 6, (+)-(-)-pinoresinol 7, and (+)-diasyringaresinol 8. The structures of these compounds were elucidated unambiguously by spectroscopic methods including 1D and 2D NMR analysis and also by comparing experimental data with literature data. The tyrosinase inhibitory potency of these compounds has been evaluated and attempts to justify their structure-activity relationships have been made in the present work. The compound 5 was found to be the most potent (IC(50)=3.21 microM) while other compounds demonstrated moderate to potent inhibitions. It was found that the substitution of functional group(s) at C-2 and C-3 positions and the presence of the -CH(2)OH group plays a vital role in the potency of the compounds. The compound 5 can act as a potential lead molecule to develop new drugs for the treatment of hyperpigmentation associated with the high production of melanocytes.
Derong Cao - One of the best experts on this subject based on the ideXlab platform.
-
syntheses characterization and biological studies of zinc ii copper ii and cobalt ii complexes with schiff base ligand derived from 2 hydroxy 1 naphthaldehyde and selenomethionine
Applied Organometallic Chemistry, 2010Co-Authors: Xueguang Ran, Lingyun Wang, Yingcai Lin, Jie Hao, Derong CaoAbstract:Novel zinc(II), copper(II), and cobalt(II) complexes of the Schiff base derived from 2-hydroxy-1-naphthaldehyde and D, L-selenomethionine were synthesized and characterized by elemental analysis, IR, electronic spectra, conductance measurements, magnetic measurements and powder XRD. The analytical data showed the composition of the metal complex to be ML(H2O), where L is the Schiff base ligand and M = Co(II), Cu(II) and Zn(II). IR results confirmed the tridentate binding of the Schiff base ligand involving azomethine nitrogen, naphthol oxygen and carboxylato oxygen atoms. 1H NMR spectral data of lithium salt of the Schiff base ligand [Li(HL)] and ZnL(H2O) agreed with the proposed structures. The conductivity values of complexes between 12.50 and 15.45 S cm2 mol−1 in DMF suggested the presence of non-electrolyte species. The powder XRD studies indicated that Co(II) complex is amorphous, whereas Cu(II) and Zn(II) complexes are crystalline. The results of antibacterial and antifungal screening studies indicated that Li(HL) and its metal complexes are active, but CuL(H2O) is most active among them. Copyright © 2010 John Wiley & Sons, Ltd.
Siangguan Teoh - One of the best experts on this subject based on the ideXlab platform.
-
inner coordination sphere tin iv complexes with some o n n terdentate n 2 hydroxybenzaldehyde 1 amino 2 phenyleneimine and n 2 hydroxy 1 naphthaldehyde 1 amino 2 phenyleneimine and o n n o quadridentate n n bis 2 hydroxybenzaldehyde 1 2 phenylenediim
Polyhedron, 1997Co-Authors: Siangguan Teoh, Guan-yeow Yeap, Laiwan FoongAbstract:From the reactions of SnCl 4 with organotin(IV) chlorides (RSnCl 3 , R 2 SnCl 2 and R 3 SnCl, where R = Bu, Me and Ph) with N -(2-hydroxybenzaldehyde)-1-amino-2-phenyleneimine, N -(2-hydroxyl-1-naphthaldehyde)-1-amino-2-phenyleneimine, N , N ′-bis(2-hydroxybenzaldehyde)-1,2-phenylenediimine and N , N ′-bis(2-hydroxy-1-naphthaldehyde)-1,2-phenylenediimine a series of complexes have been synthesized and characterized, respectively, by microanalytical, IR, and 1 H NMR spectroscopic methods. The Ph 2 SnCl 2 reacted with N -(2-hydroxy-1-naphthaldehyde)-1-amino-2-phenyleneimine giving Ph 2 Sn(NAPPDI) [where NAPPDI = deprotonated N , N ′-bis(2-hydroxy-1-naphthaldehyde)-1,2-phenylenediimine], wherein the former Schiff base exhibit a facile intramolecular CN bond cleavage and intermolecular CN bond formation.
