Muhammad Atif

University of Karachi, Kurrachee, Sindh, Pakistan

Are you Muhammad Atif?

Claim your profile

Publications (12)19.94 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Microbial catalysis is used in the commercial production of many bioactive steroids. Solid phase microbial fermentation of anabolic steroid, dihydrotestosterone (DHT, 1), was carried out with ascomycete fungal strain Fusarium oxysporum (NRRL-1392). Methods: Sabouraud-4% glucose-agar was used to cultivate the fungal cultures as solid phase medium. Substrate 1 was incubated with Fusarium oxysporum (NRRL-1392) for 8 days. Microbial transformed metabolites were purified by using column chromatographic technique. Results: Ascomycete fungal strain Fusarium oxysporum (NRRL-1392), transformed dihydrotestosterone (1) to four oxidative metabolites 2-5 using solid phase microbial transformation metod. During biotransformation process the hydroxy group was incorporated in inactivated methine carbon atoms at C-7 and C-11 positions. Their structures were elucidated by means of a homo and heteronuclear 2D NMR and by HREI-MS techniques as 17β-hydroxyandrosta-1, 4-dien-3-one 2, androsta-1, 4-diene-3, 17-dione 3, 7α, 17β-dihydroxyandrosta-1, 4-dien-3-one (4), and 11α-hydroxyandrosta-1, 4-diene-3, 17-dione 5. The relative stereochemistry of newly incorporated hydroxy groups were deduced by 2D NOESY experiment. Conclusion: In conclusion, microbial biocatalysis is an attractive alternative tool for the preparation of new bioactive steroids, which might be difficult to prepare by conventional chemical routes. Furthermore, microbial-catalyzed biotransformations can produce commercially valuable steroidal pharmaceuticals for the pharmaceutical industry. © 2015, International Journal of Pharmacy and Pharmaceutical Science. All rights reserved.
    No preview · Article · Jan 2015 · International Journal of Pharmacy and Pharmaceutical Sciences
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: A microbial biotransformation study was performed on trans-androsterone (1) using solid phase medium. In the present context, trans-androsterone (1), a sex hormone was fermented with two filamentous fungi, Rhizopus stolonifer (black bread mold) and Fusarium lini. Methods: Sabouraud-4% glucose-agar were used to cultivate the fungal cultures as solid phase medium. Substrate 1 was incubated with R. stolonifer (ATCC 10404) and F. lini (NRRL 68751) for 8 days. Microbial transformed metabolites were purified by using column chromatographic technique. Results: The metabolism study of 1 revealed that various metabolites were detected when incubated with filamentous fungi. A total of 3 transformed products were obtained. The reactions occurred that exhibited diversity; including selective hydroxylation at C-6 and C-7 along with oxidation occurs at C-3 positions. Their structure and identified on the basis of extensive spectroscopic data (NMR, HREIMS, IR and UV) as 3β,7β-dihydroxy-5α-androstan-17-one 2 in a good yield (58%), 6β-hydroxy-5α-androstan-3,17-dione 3, and 3β,6β-dihydroxy-5α-androstan-17-one 4. Conclusion: Solid phase microbial transformation method can successfully be used for the development of new steroidal drugs. The modified steroidal molecules could favor when compared to their natural counterparts due to several medicinal advantages. © 2015, International Journal of Pharmacy and Pharmaceutical Sciences. All Rights Reserved.
    No preview · Article · Jan 2015 · International Journal of Pharmacy and Pharmaceutical Sciences
  • Source
    Naik Khan · Muhammad Atif · Amal AlAboudi
    [Show abstract] [Hide abstract]
    ABSTRACT: (-)-Alloisolongifolene (1) is a structural analogue of the naturally occurring longifolene. The microbial transformation of (-)-alloisolongifolene (1) by Cunninghamella elegans afforded two new metabolites, 3a-hydroxyalloisolongifolol (2) and 13-hydroxyalloisolongifolol (3). The structures of the metabolites were deduced on the basis of their spectral data, including 1D and 2D NMR, IR and HREIMS.
    Preview · Article · Sep 2014 · Oriental Journal of Chemistry
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Dehydroabietic acid (DHA, 1), a natural occurring diterpene resin acid, is an abundant resin acid in conifers, representing a natural wood protectant. The aim of this study was to use microbial cell cultures as tools for modification of 1 in order to obtain value-added functional derivatives. A scaled-up biotransformation of 1 by filamentous fungus Cunninghamella elegans, Rhizopus stolonifer, Gibberella fujikuroi, and Cephalosporium aphidicola were conducted for the first time. Three hydroxylated metabolites; 1-hydroxydehydroabietic acid (2); 15-hydroxy dehydroabietic acid (3); and 16-hydroxy dehydroabietic acid (4). The structure of the hydroxylated metabolites were elucidated by 1-D (1H, 13C) and 2-D NMR (COSY, HMBC, HMQC, NOESY) techniques and MS analyses. Dehydroabietic acid (1) and their transformed products 2-4 exhibited a promising -Glucosidase inhibitory activity. Compound 1 showed 38 times more active than the standard alpha-Glucosidase inhibitor, deoxynojirimycin. Compound 1 and its transformed metabolites 2-4 also showed significant antibacterial activities.
    Full-text · Article · Aug 2014 · Journal of Pharmacy and Pharmaceutical Sciences
  • Source
    Sadia Sultan · MUHAMMAD ATIF · SYED ADNAN ALI SHAH
    [Show abstract] [Hide abstract]
    ABSTRACT: Dehydroabietic acid (DHA, 1), a natural occurring diterpene resin acid, is an abundant resin acid in conifers, representing a natural wood protectant. The aim of this study was to use microbial cell cultures as tools for modification of 1 in order to obtain value-added functional derivatives. A scaled-up biotransformation of 1 by filamentous fungus Cunninghamella elegans, Rhizopus stolonifer, Gibberella fujikuroi, and Cephalosporium aphidicola were conducted for the first time. Three hydroxylated metabolites; 1β-hydroxydehydroabietic acid (2); 15-hydroxy dehydroabietic acid (3); and 16-hydroxy dehydroabietic acid (4). The structure of the hydroxylated metabolites were elucidated by 1-D (1H, 13C) and 2-D NMR (COSY, HMBC, HMQC, NOESY) techniques and MS analyses. Dehydroabietic acid (1) and their transformed products 2-4 exhibited a promising α-Glucosidase inhibitory activity. Compound 1 showed 38 times more active than the standard α-Glucosidase inhibitor Keywords: Microbial transformation, Dehydroabietic acid, Antibacterial activities, , deoxynojirimycin. Compound 1 and its transformed
    Full-text · Article · Jan 2014 · International Journal of Pharmacy and Pharmaceutical Sciences
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Andrographolide (1), the main crystalline bitter principle of Andrographis paniculata nees. (also known as rice bitter in the West Indies) was first isolated by Gorter, and characterized as trihydroxy lactone. It was also isolated from Holmskilodia sanguinea in very good yield. It possesses a wide range of biological activities, which is also important in the therapeutic fields including anti-inflammatory, anti-malarial, anti-viral, immuno-stimulant, anti-HIV, and cardiovascular properties. In the present study, we first time studied the microbial metabolism of andrographolide (1) with Cunninghamella elegans (TSY 0865) and Cephalosporium aphidicola (IMI-68689).
    No preview · Article · Jan 2014 · International Journal of Pharmacy and Pharmaceutical Sciences
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The fungal transformation of cedryl acetate (1) was investigated for the first time by using Cunninghamella elegans. The metabolites obtained include, 10β-hydroxycedryl acetate (3), 2α, 10β-dihydroxycedryl acetate (4), 2α-hydroxy-10-oxocedryl acetate (5), 3α,10β-dihydroxycedryl acetate (6), 3α,10α-dihydroxycedryl acetate (7), 10β,14α-dihydroxy cedryl acetate (8), 3β,10β-cedr-8(15)-ene-3,10-diol (9), and 3α,8β,10β -dihydroxycedrol (10). Compounds 1, 2, and 4 showed α-glucosidase inhibitory activity, whereby 1 was more potent than the standard inhibitor, acarbose, against yeast α-glucosidase. Detailed docking studies were performed on all experimentally active compounds to study the molecular interaction and binding mode in the active site of the modeled yeast α-glucosidase and human intestinal maltase glucoamylase. All active ligands were found to have greater binding affinity with the yeast α-glucosidase as compared to that of human homolog, the intestinal maltase, by an average value of approximately -1.4 kcal/mol, however, no significant difference was observed in the case of pancreatic amylase.
    Full-text · Article · Feb 2013 · European Journal of Medicinal Chemistry
  • [Show abstract] [Hide abstract]
    ABSTRACT: Microbial transformation of (20S)-20-hydroxymethylpregna-1,4-dien-3-one (1) by four filamentous fungi, Cunninghamella elegans, Macrophomina phaseolina, Rhizopus stolonifer, and Gibberella fujikuroi, afforded nine new, and two known metabolites 2-12. The structures of these metabolites were characterized through detailed spectroscopic analysis. These metabolites were obtained as a result of biohydroxylation of 1 at C-6β, -7β, -11α, -14α, -15β, -16β, and -17α positions, except metabolite 2 which contain an O-acetyl group at C-22. These fungal strains demonstrated to be efficient biocatalysts for 11α-hydroxylation. Compound 1, and its metabolites were evaluated for the first time for their cytotoxicity against the HeLa cancer cell lines, and some interesting results were obtained.
    No preview · Article · Jul 2011 · Steroids
  • [Show abstract] [Hide abstract]
    ABSTRACT: Transformation of lynestrenol (19-nor-17alpha-pregn-4-en-20-yn-17beta-ol) (1) was carried out by incubation with Cunninghamella elegans to obtain 19-nor-17alpha-pregn-4-en-20-yn-3-one-10beta,17beta-diol (2), 19-nor-17alpha-pregn-4-en-20-yn-3-one-6beta,17beta-diol (3), and 19-nor-17alpha-pregn-4-en-20-yn-3beta,6beta,17beta-triol (4). Metabolite 4 was identified as a new compound. These metabolites were structurally characterised on the basis of spectroscopic techniques.
    No preview · Article · Jan 2010 · Natural product research
  • [Show abstract] [Hide abstract]
    ABSTRACT: Microbial transformation of the sesquiterpene (-)-guaiol (1) [1(5)-guaien-11-ol] was investigated using three fungi, Rhizopus stolonifer, Cunninghamella elegans, and Macrophomina phaseolina. Fungal transformation of 1 with Rhizopus stolonifer yielded a hydroxylated product, 1-guaiene-9 beta,11-diol (2). In turn, Cunninghamella elegans afforded two mono- and dihydroxylated products, 1-guaiene-3beta,11-diol (3) and 1(5)-guaiene-3beta,9 alpha,11-triol (4), while Macrophomina phaseolina produced two additional oxidative products, 1(5)-guaien-11-ol-6-one (5) and 1-guaien-11-ol-3-one (6). All metabolites were found to be new compounds as deduced on the basis of spectroscopic techniques. Compounds 1-6 were evaluated for their activity against several bacterial strains.
    No preview · Article · Jun 2007 · Journal of Natural Products
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Microbial transformation of 11α-hydroxyprogesterone (1) with Cunninghamella elegans, Gibberella fujikuroi, Fusarium lini, and Candida albicans yielded 11α,15α,16α-trihydroxypregn-4- ene-3,20-dione (3), 11α-hydroxy-5α-pregnane-3,20-dione (4), 6β ,11α-dihydroxypregn-4-ene-3,20- dione (5), 11α-hydroxypregna-1,4-diene-3,20-dione (6), 11α,17β -dihydroxyandrost-4-en-3-one (7), and 11α,15α-dihydroxypregn-4-ene-3,20-dione (8). On the other hand, microbial transformation of 17α-hydroxyprogesterone (2) with Cunninghamella elegans and Fusarium lini yielded 11α,17α- dihydroxypregn-4-ene-3,20-dione (9), and 17α-hydroxypregna-1,4-diene-3,20-dione (10). The structures of the metabolites 3 - 10 were deduced on the basis of spectroscopic methods. Compound 3 was identified as a new metabolite, which exhibited a promising inhibitory activity against the α-glucosidase enzyme.
    Full-text · Article · Apr 2007
  • [Show abstract] [Hide abstract]
    ABSTRACT: The microbial transformation of levonorgestrel (1) by Cunningham elegans resulted in the formation of five hydroxylated metabolites, 13-ethyl-10beta, 17beta-dihydroxy-18,19-dinor-17alpha-pregn-4-en-20-yn-3-one(2), 13-ethyl-6beta,17beta-dihydroxy-18,19-dinor-17alpha-pregn-4-en-20-yn-3-one (3) 13-ethyl 6beta, 10beta, 17beta-trihydroxy-18,19-dinor-17alpha-pregn-4-en-20-yn-3-one (4) 13-ethyl-15alpha-17beta-dihydroxy-18,19-dinor-17alpha-pregn-4-en-20-yn-3-one (5) and 13-ethyl-11alpha, 17beta-dihydroxy-18,19-dinor-17alpha-pregn-4en-20-yn-3-one. The fermentation of one with Rhizopus stolonifer, Fusarium lini and Curvularia lunata afforded compound 2 as a major metabolise. These metabolites were structurally characterized on the basis of spectroScopic techniques. Metabolite 6 was identified as a new compound. Compounds 2 2 ad 5 displayed inhibitory activity against the acetylcholinesterase ( AChE, EC. 3.1.1.7) with IC50 values of 79.2 and 24.5 microM, respectively. The metabolites 2 and 5 also showed inhibitory activity against the butyryLcholinesterase ( BChE, E.C 3.1.1.8) with IC50 values ranging between 9.4 and 309.8 microM.
    No preview · Article · Nov 2006 · Natural Product Research
  • [Show abstract] [Hide abstract]
    ABSTRACT: The microbial transformation of oral contraceptive norethisterone (1) by Cephalosporium aphidicola afforded an oxidized metabolite, 17α- ethynylestradiol (2), while the microbial transformation of 2 by Cunninghamella elegans yielded several metabolites, 19-nor-17α-pregna-1,3,5 (1O)-trien-20-yne-3,4,17β-triol (3), 19-nor-17β-pregna-1,3,5 (10)-trien-20-yne-3,7α,17β-triol (4), 19-nor-17α-pregna-1,3,5 (10)-trien-20-yne-3,11α,17β-triol(5), 19-nor-17α-pregna-1,3,5 (10)-trien-20-yne-3,6β,17β-triol (6) and 19-nor-17α-pregna-1,3,5 (10)-trien-20-yne-3,17β-diol-6β-methoxy (7). Metabolite 7 was found to be a new compound. These metabolites were structurally characterized on the basis of spectroscopic techniques.
    No preview · Article · Mar 2004

Publication Stats

65 Citations
19.94 Total Impact Points

Top co-authors View all

Institutions

  • 2007-2014
    • University of Karachi
      • International Center for Chemical and Biological Sciences
      Kurrachee, Sindh, Pakistan
  • 2006
    • H.E.J. Research Institute of Chemistry
      Kurrachee, Sindh, Pakistan