خالد محمد ناجي سعيد

Khalid Mohammed Naji Saeed

Associate Professor


Name: Khalid Mohammed Naji Saeed

Date of birth: 06-11-1972

Place of Birth: Ibb, Yemen

Nationality: Yemeni

Marital status: Married

Address: Chemistry Department, Faculty of Science,

                 Sana’a University, Sana’a, Yemen.

Tel: +967 777904480



Dr. Khaled Mohammad Naji joined the Department of Chemistry, Faculty of Science, Sana’a University in September 1991 to study a Bachelor’s degree (Chemistry/Biology) and graduated in July 1995 after obtaining first rank of his class with a grade of very good with honors. He was appointed as an instructor in the Department of Chemistry on July 23, 1997. In 2000, he awarded one of the Indian cultural exchange scholarship to study a master’s degree at Bangalore University – India. He obtained MSc in biochemistry in May 2002 and then completed his doctoral study at the same university from 2003 until his defensed his doctoral thesis on 28 October 2008. In February 2009, he was appointed as assistant Professor of Biochemistry at the Department of Chemistry, University of Sana’a, then He was promoted as Associate Professor in April 2016. During this period, he has taught many different chemistry subjects for undergraduate and graduate students in different departments and faculties of the university, including the faculty of Science, Education and Agriculture, as well as the Faculty of Pharmacy. Dr. Khaled took over many administrative tasks and activities and participated in many academic committees in the department and the faculty, the most prominent of which was his work as the youth pioneer of the faculty of Science during 2012 – 2018. Dr. Khaled Naji has supervised a lot of postgraduate research students for master’s and doctoral degrees. His research topics varied, in the different areas of biochemistry research, including the developing of new methods for measuring plant antioxidants, as well as studies of the effect of some extracts of some Yemeni medicinal plants and their therapeutic effects for some chronic diseases and various toxic effects. In addition to biodegradation and enzymes research. Also, some studies were carried on the on the effect of khat on its abusers. Dr. Khaled has published many research papers in peer-reviewed international journals with impact factor (Q1 and Q2). Currently, Dr. Khaled is working as a visiting scientist at the University of Konstanz, Germany, after he awarded and conducted a post-doctoral fellowship (Post-Doc) during Oct 2018 – Dec 2020.



Post-Doctoral (PD): University of Konstanz, Germany 11/2018 – 12/2020.

PhD (Biochemistry): Bangalore University, India. 2003- 2008. Awarded 28/10/2008.

Thesis Title: Response of Horse gram (Mycrotyolma uniflorum) to abiotic stress

MSc (Biochemistry): Bangalore University. Awarded 31/7/2002.

Thesis Title: Partial purification and characterization of esterase from Dolichos lablab seeds

BSc (Chemistry & Biology), Sana’a University, Sana’a, Yemen. Awarded 7/1995. (3.52 Honors)



– Arabic: Mother tongue

– English: (Speaking- Reading- listening) – Excellent

– German: Basic



Research experience:

  • Working on cutting edge research in Biodegradation of xenobiotics including Cloning and expression of secondary metabolite enzymes involved in phthalate and isophthalate degradation by some anaerobic bacteria using the ultimate techniques such as LC-MS and GC-MS. (2018 Nov- 2021 Dec) Konstanz university, Germany.
  • Supervisor of many PhD and MSc students in different topics of Biochemistry and physiology including antioxidants measurements, activity of some Yemeni medicinal plants, impact of Khat chewing effect, purification of some hydrolytic enzymes and biodegradations of some environmental pollutants. (2009-2018) Sana’a University
  • Ph D research work, Bangalore University, India (2003-2008)


Technical experience & research skills:

Protein Chemistry

  • Expression and purification of recombinant proteins, quantification of proteins polyacrylamide gel electrophoresis, western blots, ELISA, ultracentrifuge techniques
  • Enzyme assays, using LC-MS, GC-MS

Molecular biology

  • General DNA manipulations, restriction enzyme digestion, DNA/RNA extraction and purification
  • PCR and RT-PCR techniques, agarose gel electrophoresis,
  • Cloning, reverse transcription.

Microbiology techniques

  • Isolation and identification of aerobic and anaerobic bacteria, use of light microscope, glove box and Widdel techniques.

Natural products

  • Medicinal plants, Extraction, fractionation, identification and quantification active compounds


Peer Review experience:

  • Inner and external Examiner for the PhD and MSc thesis.
  • Examiner for the graduation projects, Faculty of Pharmacy, Sana’a University. 2016- 2017.
  • Editor of Faculty of Science Bulletin (FSB) –Sana’a University. 2012- 2015
  • Technical editor of the following journals:
  • Pakistan Journal of Biological Sciences, Journal of Biological Sciences, Asian Journal of Biochemistry, Journal of Pharmacology and Toxicology and American Journal of Biochemistry and Molecular Biology
  • Reviewer for many international journals e. g Substance Use and Misuse, Full peer review details are available at my peer-review page:


Teaching Experience:

Associate/ assistant professor of Biochemistry:  Sana’a University (2009 – 2018).


– BSc. Chemistry and Biology: General Chemistry, General Biochemistry (Chemistry of Biomolecules), Metabolism, Basic Enzymology, Medical Biochemistry, Biochemical techniques, Organic Chemistry for Biologists, Graduation project supervisor.

– B. Pharma, Faculty of Pharmacy, (2015-2018): the following subjects

General Biochemistry, Medical Biochemistry, Metabolism, Basic Enzymology, Clinical Biochemistry.

Postgraduate students: 2012 – 2018 (MSc. Microbiology):

Protein purification techniques and enzymology (Including enzyme kinetics, assays, and applications)

Instructor: Department of Chemistry, Sana’a University (1997 – 2000)

Tutoring laboratory practical classes including the following practical subjects: General Chemistry, Organic Chemistry (identification and synthesis of organic compounds), Biochemistry and Analytical Chemistry.


Academic Administrative Experience

  • – Head of Chemistry department 2012-2013
  • – Youth Pioneer, Faculty of Science, Sana’a University, 2012 – 2018
  • – Head of postgraduate committee, Chemistry dept. Faculty of Science, Sana’a Univ. 2013- 2018
  • – Member of student affair committee, Faculty of Science, Sana’a Univ. 2012- 2018
  • – Member of the admission committee, Faculty of Pharmacy, Sana’a University. 2015-2018.


Consultation Experience

– Head of the National Cosmetics standards committee, YSMO, Sana’a- Yemen. (Member of GCS). 2011-2018

– Member of the national Fabrics & Leathers Standards committee, YSMO, Sana’a- Yemen. (Member of GCS). 2012- 2018

– Head of the National Detergents & Chemicals Standards Committee, YSMO, Sana’a- Yemen. (Member of GCS). 2014 – 2018.



  • Fellowship of Baden-Württemberg fund for persecuted scholar (BWFPS) 2018
  • Award scholarship of Indian Council for cultural relations (ICCR), 2000
  • First rank of BSc. (Honor) Chemistry Dept. Faculty of Science, Sana’a University 1995


Training Courses & Workshop

  • “Instructional strategies, Instruction techniques and methods of evaluation” Training program for Sana’a University faculties, Center of undergraduate instruction development, Sana’a University, Sana’a. (04-18) August, 2009.
  • Training in RNAi techniques associated with stress physiology “RNAi Technology and applications” short term training course for Mid-Career Scientists & UG/PG Faculty. Held in Maharani’s Science College for Women – Bangalore – India. February (10-25) 2014.

Online webinar:

  1. – Preparation of your manuscript, Elsevier publishing campus. 19-Apr 2016
  2. – How to become A reviewer and what do editor expect. Elsevier publishing campus. 23 Mar 2017.
  3. – How to write an abstract and improve your article. Elsevier publishing campus. 5 Dec. 2017


  • Dowman S., Naji K. M, Al-Mahdi, A. Y., Humid, A. Physicochemical characteristics and total phenols for some famous Yemeni honey and the extent of conformity with regional and international standards. 8th Scientific conference of The Yemeni Biological Society, IBB University, IBB, Yemen September 13-15. (2014)
  • Naji, K. M., Al-Maktari, M. A., Al-Hazmi, S. M., Assessment of some biochemical constituents in blood of people chewing Khat (Catha edulis) in Sana’a city, Yemen. 7th Scientific conference of The Yemeni Biological Society, held in Cultural center, Sana’a, Yemen. Sep. 28-29 (2010)
  • Naji, K. M.  and Devaraj V. R. Biochemical responses of tissue cultured and normal seedlings of Horse gram (Macrotyloma uniflorum) under drought stress, a comparative study. 6th Scientific conference of The Yemeni Biological Society Taiz- Yemen. November 14-15. (2009)
  • Naji, K. M.  and Devaraj V. R. “Antioxidant Enzymes and Antioxidants of Horse gram (Macrotyloma uniflorum) During Abiotic Stress. 75 th Annual meeting of society of biological chemists held in Jawahar Lal Nehru University (JNU) New Delhi, INDIA. December 18-20. (2006)
  • Naji, K. M.  and Devaraj V. R. Antioxidants and Antioxidant enzymes of horse gram (Macrotyloma uniflorum) during high temperature stress. National conference of Chemistry, held at Chemistry dept. Bangalore University Bangalore, India. September 27-29. (2006)
  • Naji, K. M.  and Devaraj V. R. Effect of high temperature stress on Horse gram (Macrotyloma uniflorum)”. The Life science symposium on “Molecular biology of stress response and its applications” sponsored by DAE-BRNS held at Bhabha Atomic research center (BARC) – Mumbai, India. December 19-21. (2005)



  1. Naji, K. M., Al-Khatib, B. Y., Al-Haj, N. S., D’souza M. R. Hepatoprotective Activity of Melittin on Isoniazid- and Rifampicin-Induced Liver Injuries in Male Albino Rats. BMC Pharmacology & Toxicology 2021. 22 (1), 1-11
  2. Naji, K. M., Thamer, F. H., Numan, A. A., Dauqan, E. M., Alshaibi, Y. M., D’souza, M. R.  Ferric-Bipyridine Assay: A novel spectrophotometric method for measurement of antioxidant capacity. Heliyon, (2020) 6: e03162
  3. Shediwah, F. M. H., Naji, K. M., Gumaih, H. S., Alhadi, F. A., Al-Hammami, A. L., D’souza, M. R. Antioxidant and antihyperlipidemic activity of Costus speciosus against atherogenic diet-induced hyperlipidemia in rabbits. Journal of Integrative Medicine. (2019) 17:181-191
  4. Al.Maqtari, M. A., Naji, K. M., Ali, L. K., Extraction and Immobilization of Proteolytic Enzymes from Local Yemeni Bean Seeds (Dolichos Lablab L.). American Research Journal of Biosciences (2019) 5:1-6
  5. Marea, S., Naji, K. M., Gawli, K., Rajesha, J. Protective Effect of Secoisolariciresinol Diglycoside in Carbon Tetrachloride Induced Hepatotoxicity in Rats. Journal of Clinical & Cellular Immunology. (2018) 9:567-573.
  6. Mohammed, F., Abdulwali, N., Guillaume, D., Tenyang, N., Ponka, R., Al-Gadabi, K., Naji, K. M. Chemical composition and mineralogical residence of sesame oil from plants grown in different Yemeni environments. Microchemical Journal (2018)140: 269–277
  7. Abdullah, Q. Y., Edrees, W. H., Al-kaf, A. G., & Naji, K. M. Biodegradation of Paracetamol by Native Bacterial Strains Isolated from Yemeni Pharmaceutical Wastewater Plant in Sana’a. Chronicles of Pharmaceutical Science (2018) 2:512-522.
  8. Al-Maydama, H. M., Abduljabbar, A. A., Al-Maqtari, M. A., Naji. K. M. Study of Temperature and Irradiation Influence on the Physicochemical Properties of Aspirin. Journal of Molecular Structure (2018) 1157:364–373.
  9. Edrees, W. H., AL-Kaf, A G., Abdullah, Q. Y., Naji. K. M., Isolation and Identification of a New Bacterial Strains Degrading Paracetamol Isolated from Yemeni Environment. Clinical Biotechnology and Microbiology (2018) 1:257–70
  10. Edrees, W. H., Qais Y. Abdullah, Naji, K. M., AL-Kaf, A. G., Biodegradation of Paracetamol by Native Fungal Species Inhabiting Wastewater of a Pharmaceutical Factory in Sana’a, Yemen. Universal Journal of Pharmaceutical Research (2018) 2:35–41.
  11. Thamer, F. H., Dauqan, E. M. A., Naji, K. M. The effect of drying temperature on the antioxidant activity of thyme extracts. Journal of Food Technology and Preservation (2018) 2:15-19.
  12. Naji, K. M., Al-Shaibani, E. S., Alhadi, F. A., D’souza, M. R. Hepatoprotective and antioxidant effects of single clove garlic against CCl 4-induced hepatic damage in rabbits. BMC Complementary and Alternative Medicine (2017) 17: 411.
  13. Al-Maqtari, M. A., Naji, K. M., Ali, L. K., Purification and Characterization of Proteolytic Enzymes from Local Yemeni Bean Seeds (Dolichos Lablab l.). Journal of Modern Science & Engineering (2017) 1:8–13.
  14. Al-Kaf, A. G., Naji, K. M., Abdullah, Q. Y. M., Edrees, W. H. A. Occurrence of Paracetamol in Aquatic Environments and Transformation by Microorgan-isms: A Review. Chronicles of Pharmaceutical Science (2017) 1:341-355.
  15. Dauqan, E. M. A., Thamer, F. H., Naji, K. M., Alshaibi, Y. Different Extraction Methods and Antioxidant Properties of Thyme (Thymus vulgaris L.) Herb. International Journal of Chemical Science (2017) 1:110–116.
  16. Wadhah H. A. E., Abdullah, Q. Y. M., AL-Kaf, A. G., Naji, K. M., A Review on Comparative Study Between the Physicochemical and Biological Processes for Paracetamol Degradation” Universal Journal of Pharmaceutical Research (2017) 2:18-27
  17. Naji, K. M., & V R. Devaraj. Alteration of amylase and phosphatase in Macrotyloma uniflorum under influence of cadmium, mercury and zinc stress. Malaysian Journal of Biochemistry & Molecular Biology (2016) 2:8-14.
  18. Naji, K. M., Maher A. Al-Maqtari, Adnan A. Al-Asbahi, Qais Y. M. Abdullah, Nagesh B. R, V R Devaraj Effect of daily chewing soft buds and leaves of Catha edulis (Khat) on the antioxidant defence system and oxidative stress markers in blood Arabian Journal for Science and Engineering (2015)40 :1-6
  19. Naji, K. M., Qais Yusuf A, Aida Q. Al-Zagri, Saeed M. Alghalebi. Evaluating the biodeterioration enzymatic activities of fungal contamination isolated from some Ancient Yemeni mummies preserved in the national museum Biochemistry Research Journal. (2014) 2014:1-9
  20. Naji, K. M., Devaraj V. R., Biochemical Response Trends of Macrotyloma uniflorum, Lam. Subjected to Dehydration Stress in Different Growth Conditions, World Applied Sciences Journal (2013) 28:934-941.
  21. Al-Ashwal, R. H., Al-Maqtari, M. A., Naji, K. M., Al-wsabai, N. A., Al-Hazmy, S. M., Potential Health Effects of Daily Khat Leaves Chewing: Study on The Biochemical Blood Constituents Changes among Adults, in Sana’a city, Yemen. International Journal of Biochemistry and Biotechnology (2013) 2:461-463
  22. Naji, K. M., Al-Maqtari, M. A., Abdullah, Q. Y. Influence of Khat on the Level of Clinical Biomarkers in Blood of Khat Chewers; Faculty of Science Bulletin, Sana’a University (2012) 24:103-109.
  23. Al-Asbahi, A. Ali, Al-Maqtari, M. A., Naji, K. M., ABA biosynthesis defective mutants reduce some free amino acids accumulation under drought stress in tomato leaves in comparison with Arabidopsis plants tissues; Journal of Stress Physiology & Biochemistry (2012) 8:179-192.
  24. Al Maqtari, M. A., Naji, K. M., Al Hazmi, S. M., Identification and Characterization of α-Amylase from Yemeni Bean (Dolichos Lablab L.) Seeds. Jordan Journal of Chemistry (JJC) (2011) 6:219-229
  25. Naji, K. M., Devaraj, V. R., Antioxidant and other biochemical defense responses of Macrotyloma uniflorum (Lam) Verdc. (Horse gram) induced by high temperature and salt stress; Brazilian Journal of Plant Physiology (2011) 23:187-195
  26. Naji, K. M., Devaraj, V. R., Partial Purification and Characterization of Newly Expressed Guaiacol Peroxidase from dehydrated Seedlings of Horse Gram (Macrotyloma Uniflorum) Tissue Culture; Faculty of Science Bulletin, Sana’a University (2009) 22:39:48.



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