Group Leader
Prof. Olorunfemi Abraham Eseyin
Department of Pharmaceutical and Medicinal Chemistry
Faculty of Pharmacy
University of Uyo
Nigeria
E-mail: olorunfemieseyin@uniuyo.edu.ng
Phone: +2348065161478
Dr. Ekarika johnson
Dr Ekarika Clement Johnson is an experienced researcher in natural products chemistry and pharmaceutical analysis and a thorough bred academic. He holds B.Sc. degree in Chemistry from University of Calabar where he obtained the Prize for the best graduating student in 1985; M.Sc. and Ph.D in Pharmaceutical and Medicinal Chemistry from Ahmadu Bello University, Zaria. He is currently the Acting Head of Department of Pharmaceutical and Medicinal Chemistry University of Uyo and Editor of reputed academic journals including; NIJOSPHASR and JDPS. He has research interest in tropical medicinal plants from which he has isolated useful compounds some of which have been published in international and local Journals. He is a member of professional and research groups like Chemical Society of Nigeria and Science Teachers Association of Nigeria, Western Africa Network of Natural Products Research Scientists (WANNPRES) as well as Drug Discovery and Research Group of University of Uyo.
Visible online via the following links:
1. https://www.researchgate.net/profile/Ekarika_Johnson
2. https://uniportal.academia.edu/Rikajohnsonhttps://www.linkedin.com/in/ekarika-johnson-
3. LIVE DNA: 234.16796
4. Orchid Id: 0000-0002-0932-5245
5. Web of Science id: U-1780-2019
Email: ekarikajohnson@uniuyo.edu.ng; rikaisable@gmail.com
Some of his Published Works are
1. Dosunmu, M. I. &Johnson, E. C. (1995), Chemical Evaluation of Nutritive Value and Changes in the Ascorbic Acid content during Storage of the Fruit of Bitter Kola (Garcinia kola); Food Chem., 54, 67 – 71
2. Choudhury M. K., Haruna A. K., Johnson, E. C., & Houghton P. J., (1997), Structural Elucidation of Columbin; A Diterpene from the Rhizomes of Aristolochia albida; Ind. J. Pharm. Sci. (Jan. – Feb.) 34 - 37
3. Choudhury, M. K., Johnson, E. C., & Agbaji A. S., (2000), Chemical Investigation of the bark of Commiphora africana (Bursaraceae), Ind. J. Pharm. Sci. (Jul. – Aug.), 3
4. Johnson, E. C., Eseyin, O. A., Udobre, A. S. & Ike P., (2011), Antibacterial Effect of Methanolic Extract of the Root of Aspilia africana, Nig. J. Pharm & Appl. Sci. Res. (NIJOPHASR) 1 (1): 44-50
5. Eseyin, O. A., Ebong, A., Udobre, A., Johnson, E.& Udo, I. (2012), Changes in Some Pharmacokinetics Parameters of Chloroquine by Gnetum Africana; Maced J. Med. Sci. http//dx.doi.org/10.3889/MJMS.1857-5773.2012.0220.
6. Johnson, E., Choudhury, M., Eseyin O. A. & Udobre A.S. (2012), Pharmacological Studies of the bark of Commiphora africana (Burseraceae), J. Pharmacol. And Toxicol.7 (1): 52-57
7. Etim, E. I., Johnson, E. C., Akwaowo, A. E. and Dent, C. (2014), Artemisinin Combination Therapy on some Liver Biochemicals in Nigerian Male Subjects World J. Applied Sci. And Tech.5 (1) 41 - 48
8. Eseyin O. E., Etiemmana G. C., Enobong M., Ebong A., Etim I., Udobre A. S., Johnson E., Attih, E. and Effiong A. (2015) Evaluation of some Antioxidant Properties of Some Commonly Eaten Vegetables in Akwa Ibom State of Nigeria, Annual Research& Review in Biology5(2): 165-173.
9. Olawale H. O. and Johnson E. C. (2015) Glucolipid from the ethyl acetate fraction of Acalypha wilkesiana var. lace-acalypha (Muell & Arg) J. Pharmacy & Bioresources 12(1), 48-53 (2015) http://dx.doi.org/10.4314/jpb.v12i1.7
10. Eseyin O. E., Etiemmana G. C., Enobong M., Ebong A., Etim I., Udobre A. S., Johnson E., Attih, E. and Effiong A. (2015) Evaluation of some Antioxidant Properties of Some Commonly Eaten Vegetables in Akwa Ibom State of Nigeria, Annual Research& Review in Biology5(2): 165-173.
11. Udobre, A.S., Udoh, A.E., Etim, E.I., Umoh, U.F. and Johnson, E.C., (2016)
GC-MS Analysis of Six Bioactive Compounds Isolated From The Ethanol Leaf Extract of Andrographis Paniculata( Acanthaceae) Chemistry Research Journal1(2):6-10 Available online www.chemrj.org
12. Udobre, A.S., Etim, E.I., A.E.Udoh, Umoh, U.F. and Johnson,E.C.(2016). Elevation of chloroquine potency by administering it along with dapsone in mice infected with plasmodium berghei. Journal of Pharmaceutical and Biological SciencesISSN: 2320-1924; CODEN: JPBSEV Published by Atom and Cell Publishers ©. Available online at: http://www.jpabs.org/ Original Article 4(4): 121-125.
13. Johnson, E.C., Ilyas, M. Eseyin, O.A., Etim, E.I. Udobre, A.S. Udoh, A.E. Edem, E.O. (2016) Isolation, Characterization and Anti-Diabetic Potentials of Oleanolic Acid from the Leaves of Aspilia africana (Pers) C.D Adams (Asteraceae). Journal of Pharmaceutical and Medicinal Research 2(2) (2016) 62–65. (Journal homepage: www.jacsdirectory.com/jpmr )
14. Johnson, E. C., Ilyas, M., Sule, M. I. Eseyin, O. A. Oladimeji, H O., Etim, E. I. and Udobre, A. S.(2016). Antimicrobial activity of compounds isolated from the leaves of Aspilia africana (Pers.) C. D. Adams (Asteraceae) Afr. J. Pharmacol. Ther.5(3): 149-154 (Open Access to full text available at http://journals.uonbi.ac.ke/ajpt)
15. Udobre, A.S., Udoh, A.E., Etim, E.I., Umoh, U.F. and Johnson, E.C., (2016)
GC-MS Analysis of Six Bioactive Compounds Isolated From The Ethanol Leaf Extract of Andrographis Paniculata( Acanthaceae) Chemistry Research Journal1(2):6-10 Available online www.chemrj.org
16. Etim, E., Udobre, A., Johnson, E., Udoh, A. and Essien, E. (2016) Development and Validation of UV Spectrophotometric Method for the Determination of Artesunate and Dihydroartemisinin by Coupling; The Pharma innovation Journal; 5 (8): 4-7. (Available online @ www.thepharmajournal.com.)
17. Johnson, E. C, Etim, E. I., and Archibong, E. O. (2017) Isolation and Anti-oxidant Potentials of Parahydroxybenzaldehyde from the Methanol Leaf Extract of Aspilia Africana (Pers.) C.D. Adams (Asteraceae) Nigerian Journal of Pharmaceutical and Applied Science Research, (NIJOPHASR) 6(1):26-32.
18. Eseyin, A. Akaninyene D, Thomas S. P, Attih, E., Essien E., Johnson E., Abdul Sattar M Z, Ahmad A., Sheryar A & Akpan U. (2017): Phytochemical analysis and antioxidant activity of the seed of Telfairia occidentalis Hook (Cucurbitaceae), Natural Product Research, DOI: 10.1080/14786419.2017.1308366
19. Olorunfemi A. Eseyin, Akaninyene Daniel, Thomas S. Paul, Emmanuel Attih, Essien Emmanuel, Johnson Ekarika, Abdul Sattar Munavvar Zubaid, Ahmad Ashfaq, Sheryar Afzal & Akpan Ukeme (2017): Phytochemical analysis and antioxidant activity of the seed of Telfairia occidentalis Hook (Cucurbitaceae), Natural Product Research, DOI: 10.1080/14786419.2017.1308366
20. Attih, E. E., Oladimeji, H. O. and Johnson, E. C. (2017) Optimized Validated Methods for the Evaluation of Artemisinin Derivatives in Pharmaceuticals Using Redox Reactions Nigerian Journal of Pharmaceutical and Applied Science Research, (NIJOPHASR) 6(2):69-75.
21. Ekarika Johnson, Anwanabasi Udoh, Emmanuel Etim, Emmanuel Attih and Imoiboho Williams (2018) Phytochemical Studies, Proximate and Mineral composition of Ethanol Leaf Extract of Duranta repens Linn (Verbenaceae) Research J. Phytochem. 12: 1-6
22. Attih, E. E., Johnson, E. C., Ambe, D. A., Umoh, A and Akpan A., (2018) Sensitive Titrimetric and Spectrophotometric Determination of Artesunate in Pharmaceuticals using Chloramine T as Oxidimetric reagent, Journal of Chemical and Pharmaceutical Research 10(2): 11-19
23. Ubobre, A. S., Etim, E. I., Udoh, A. E. and Johnson, E. C. (2018), Chemical Constituents of Tetrapleura tetraptera (Fabaceae) and their Antimicrobial Activities, Nigerian Journal of Pharmaceutical and Applied Science Research, (NIJOPHASR) 7(1): 52-55
24. Richard. A Ukpe and Ekarika C. Johnson. (2019)Assessment of levels of Heavy Metals in Mechanic Village Dumpsite (along Imiringe Road) in Yenagoa.Nigerian Journal of Pharmaceutical and Applied Science Research, 8(2): 103-106
25. Ekarika Johnson, Emmanuel Etim, Anwanabasi Udoh and Olorunfemi Eseyin (2019) The Proximate Composition, Mineral Element Contents and Physicochemical Properties of the Flower Oil of Aspilia africana (Pers.) C. D. Adams (Asteraceae) Nigerian Journal of Pharmaceutical and Applied Science Research, 8(2): 84-88
26. Emmanuel Attih and Ekarika Johnson (2019) Developed and Validated Spectrophotometric Methods for the Evaluation of Artesunate and Dihydroartemisinin in Tablets Using Potassium Permanganate. Nigerian Journal of Pharmaceutical and Applied Science Research, 8(2): 25-32
