The Experts below are selected from a list of 24 Experts worldwide ranked by ideXlab platform
Rosendo A Yunes - One of the best experts on this subject based on the ideXlab platform.
-
a new anti oedematogenic nor Pregnane Derivative isolated from mandevilla illustris
Planta Medica, 2002Co-Authors: Rivaldo Niero, Ricardo V Alves, Valdir Cechinel Filho, Joao B Calixto, Jane E Hawkes, Antonio Euzebio Goulart Santana, Rosendo A YunesAbstract:A new nor-Pregnane Derivative (2,6-dideoxy-3- O-methylpyranosylillustrol) (1), isolated from the ethyl acetate extract of Mandevilla illustris rhizomes, was identified by conventional spectral analysis and by chemical means. It markedly inhibited the rat paw oedema induced by carrageenan and, to a lesser extent, those induced by dextran, without affecting that caused by bradykinin.
Gabriele M. König - One of the best experts on this subject based on the ideXlab platform.
-
Caught between triterpene- and steroid-metabolism: 4α-carboxylic Pregnane-Derivative from the marine alga-derived fungus Phaeosphaeria spartinae.
Steroids, 2013Co-Authors: Mahmoud Fahmi Elsebai, Stefan Kehraus, Gabriele M. KönigAbstract:Abstract Investigation of the fungus Phaeosphaeria spartinae , an endophyte of the marine red alga Ceramium sp., led to the isolation of spartopregnenolone ( 1 ), a metabolite whose structure includes features of triterpenes and steroids, i.e. a Δ 8,9 double bond as occurring in lanosterol type triterpenoids, a carboxyl group at C-4 which is characteristic for intermediates on the way from triterpenes to steroids and an acetyl side chain as typical for Pregnane type steroids. The unusual structure of compound 1 was established from extensive spectroscopic investigations and is best described as a 4α-carboxy-8,9-pregnene Derivative.
Eugene Bratoeff - One of the best experts on this subject based on the ideXlab platform.
-
steroidal antiandrogens and 5alpha reductase inhibitors
Current Medicinal Chemistry, 1999Co-Authors: Eugene Bratoeff, Elena Ramirez, G Flores, E Murillo, Marisa CabezaAbstract:The purpose of this work is to synthesize a Pregnane Derivative with a high antiandrogenic effect or a high inhibitory activity for the enzyme 5 alpha-reductase type 2. Benign prostatic hyperplasia and prostate cancer are androgen dependent diseases which afflict a large percentage of the male population. Dihydrotestosterone 3, a 5 alpha-reductase metabolite of testosterone 2 has been implicated as a causative factor in the progression of these diseases, largely through the clinical evaluation of males who are genetically deficient of steroid 5 alpha-reductase enzyme. As a result of this study, the inhibition of this enzyme has become a pharmacological strategy for the design and synthesis of new drugs. The advent of finasteride 22 "figure 5" a 5 alpha-reductase inhibitor, has greatly alleviated the symptoms associated with benign prostatic hyperplasia. On the other hand, the discovery of cyproterone acetate 4 "figure 2" alone or in combination with the antiandrogens flutamide 14 "figure 3" or bicalutamide 21 has greatly reduced the misery of prostate cancer. Prostate cancer kills about 40,000 men in the USA and approximately 400,000 prostatectomies are performed each year. In our laboratory we have recently synthesized ten new progesterone Derivatives 17 alpha-acyloyloxy-6-halo (chloro, bromo) 16 beta-methyl-4, 6-pregnadiene-3, 20-diones (54a-54e and 55a-55e), "figure 10". These steroids were evaluated as antiandrogens and exhibited a much higher activity than the commercially available cyproterone acetate 4. The same compounds were also evaluated as 5 alpha-reductase inhibitors and showed a slightly higher inhibitory activity than that of finasteride 22, the drug of choice today for the treatment of benign prostatic hyperplasia In another study we synthesized several new 4-halo (bromo and chloro) 17 alpha-benzoyloxy and also 4-halo-17 alpha-acetoxy progesterone Derivatives (58-63) "figure 13". These compounds were prepared from the commercially available 17 alpha-acetoxy progesterone 56. The pharmacological evaluation of these steroids "figure 14" indicated that the 17 alpha-benzoyloxy Derivatives (4-chloro and bromo) 62 and 63 were very potent antiandrogens. On the other hand, the 4-halo (bromo and chloro) 17 alpha-acetoxy (58, 59) and the 17 alpha-benzoyloxy-4-chloro analog 63 showed a very high inhibitory activity for the enzyme 5 alpha-reductase type 2 "figure 15".
-
17α acetoxy 17β methyl 16β phenyl d homo 4 6 pregnadiene 3 17a dione synthesis and crystal structure determination of a new rearranged Pregnane Derivative
Journal of Chemical Crystallography, 1998Co-Authors: Manuel Sorianogarcia, Simon Hernandezortega, Eugene Bratoeff, Norma Valencia, Elena Ramirez, G FloresAbstract:The title compound is C29H34O4, tetragonal, P43, a = b = 10.310(1), c = 23.871(2)A. The A, B, C, and D rings adopt envelope, half-chair, chair, and distorted chair conformations, respectively. The phenyl ring is planar. The methyl substituents at the A/B, C/D, and at C(17) are axial; and the –OCOCH3 group at C(17) and phenyl ring at C(16) are equatorial. The molecules in the crystal are held together by van der Waals forces and several C–H···O hydrogen bond interactions.
G Flores - One of the best experts on this subject based on the ideXlab platform.
-
steroidal antiandrogens and 5alpha reductase inhibitors
Current Medicinal Chemistry, 1999Co-Authors: Eugene Bratoeff, Elena Ramirez, G Flores, E Murillo, Marisa CabezaAbstract:The purpose of this work is to synthesize a Pregnane Derivative with a high antiandrogenic effect or a high inhibitory activity for the enzyme 5 alpha-reductase type 2. Benign prostatic hyperplasia and prostate cancer are androgen dependent diseases which afflict a large percentage of the male population. Dihydrotestosterone 3, a 5 alpha-reductase metabolite of testosterone 2 has been implicated as a causative factor in the progression of these diseases, largely through the clinical evaluation of males who are genetically deficient of steroid 5 alpha-reductase enzyme. As a result of this study, the inhibition of this enzyme has become a pharmacological strategy for the design and synthesis of new drugs. The advent of finasteride 22 "figure 5" a 5 alpha-reductase inhibitor, has greatly alleviated the symptoms associated with benign prostatic hyperplasia. On the other hand, the discovery of cyproterone acetate 4 "figure 2" alone or in combination with the antiandrogens flutamide 14 "figure 3" or bicalutamide 21 has greatly reduced the misery of prostate cancer. Prostate cancer kills about 40,000 men in the USA and approximately 400,000 prostatectomies are performed each year. In our laboratory we have recently synthesized ten new progesterone Derivatives 17 alpha-acyloyloxy-6-halo (chloro, bromo) 16 beta-methyl-4, 6-pregnadiene-3, 20-diones (54a-54e and 55a-55e), "figure 10". These steroids were evaluated as antiandrogens and exhibited a much higher activity than the commercially available cyproterone acetate 4. The same compounds were also evaluated as 5 alpha-reductase inhibitors and showed a slightly higher inhibitory activity than that of finasteride 22, the drug of choice today for the treatment of benign prostatic hyperplasia In another study we synthesized several new 4-halo (bromo and chloro) 17 alpha-benzoyloxy and also 4-halo-17 alpha-acetoxy progesterone Derivatives (58-63) "figure 13". These compounds were prepared from the commercially available 17 alpha-acetoxy progesterone 56. The pharmacological evaluation of these steroids "figure 14" indicated that the 17 alpha-benzoyloxy Derivatives (4-chloro and bromo) 62 and 63 were very potent antiandrogens. On the other hand, the 4-halo (bromo and chloro) 17 alpha-acetoxy (58, 59) and the 17 alpha-benzoyloxy-4-chloro analog 63 showed a very high inhibitory activity for the enzyme 5 alpha-reductase type 2 "figure 15".
-
17α acetoxy 17β methyl 16β phenyl d homo 4 6 pregnadiene 3 17a dione synthesis and crystal structure determination of a new rearranged Pregnane Derivative
Journal of Chemical Crystallography, 1998Co-Authors: Manuel Sorianogarcia, Simon Hernandezortega, Eugene Bratoeff, Norma Valencia, Elena Ramirez, G FloresAbstract:The title compound is C29H34O4, tetragonal, P43, a = b = 10.310(1), c = 23.871(2)A. The A, B, C, and D rings adopt envelope, half-chair, chair, and distorted chair conformations, respectively. The phenyl ring is planar. The methyl substituents at the A/B, C/D, and at C(17) are axial; and the –OCOCH3 group at C(17) and phenyl ring at C(16) are equatorial. The molecules in the crystal are held together by van der Waals forces and several C–H···O hydrogen bond interactions.
Rivaldo Niero - One of the best experts on this subject based on the ideXlab platform.
-
a new anti oedematogenic nor Pregnane Derivative isolated from mandevilla illustris
Planta Medica, 2002Co-Authors: Rivaldo Niero, Ricardo V Alves, Valdir Cechinel Filho, Joao B Calixto, Jane E Hawkes, Antonio Euzebio Goulart Santana, Rosendo A YunesAbstract:A new nor-Pregnane Derivative (2,6-dideoxy-3- O-methylpyranosylillustrol) (1), isolated from the ethyl acetate extract of Mandevilla illustris rhizomes, was identified by conventional spectral analysis and by chemical means. It markedly inhibited the rat paw oedema induced by carrageenan and, to a lesser extent, those induced by dextran, without affecting that caused by bradykinin.