2020

• Fatma Elzahraa Metwally, Amal A. A. Mohamed, Usama A. Mahalel, Mohamed G. Sheded (2020). Evaluation of Certain Cosmopolitan Hydrophytes in the Nile River, Aswan District for Their Ecological and Bioactivity Potentials: A Review. International Journal of Scientific & Technology Research, 9: 1599-1606.
• Ibrahim B. Abdel-Farid, Usama A. Mahalel, Mohamed S. Massoud, Mohamed M. Rowezek, Hazem M. Ali, Khaled F. ElMassrym, Ahmed H. El-Ghorab, Mohamed Jahangir, Mariam Allach, Ibrahim L. Sabouni (2020). Metabolomic characterization and antioxidant activity of three varieties of Olea europaea growing in Aljouf region, Saudi Arabia. Sylwan, 164: 61-85.
• Ghada A. Taha, Ibrahim B. Abdel-Farid, Hassan A. Elgebaly, Usama A. Mahalel, Mohamed G. Sheded, May Bin-Jumah, Ayman M. Mahmoud (2020). Metabolomic profiling and antioxidant, anticancer and antimicrobial activities of Hyphaene thebaica.  Processes 8: 1-14. (Impact Factor: 1.963 (2018))

2019

• -Ridha Ben Saida, Arafa I. Hamed, Milena Masullo, Abdullah S. Al-Ayed, Mahmoud F. Moustafa, Usama A. Mahalel, Sonia Piacente. (2019). Flavone C-glycosides from Vaccaria pyramidata: Structure elucidation by spectroscopy and theoretical calculations. Phytochemistry Letters, 29:119-124. (Impact Factor: 1.338).
• -Sabry A. El-Naggar, Usama A. Mahalal, Ibrahim B. Abel-Farid (2019). Phytochemical analysis and anticancer activity of some medicinal plants grown in the Kingdom of Saudi Arabia. Pakistan Journal of Pharmaceutical Sciences, 2019. Proof. (Impact Factor 0.596).

2018

• -Ahlam Zakaria, Fatma F. Abdel-Motaal, Usama A. Mahalel. (2018). Antifungal activity of Ficus sycomorus L. extracts against dermatophytes and other associated fungi isolated from Camels ringworm lesions.

2017

• -Arafa I. Hamed, Ridha Ben Said, Abdullah S. Al-Ayed, Jaroslaw Moldoch, Usama A. Mahalel, Ayman M. Mahmoud, Hassan A. Elgebaly, Andy J. Perez & Anna Stochmal. (2017). Fingerprinting of strong spermatogenesis steroidal saponins in male flowers of Phoenix dactylifera (Date Palm) by LC-ESI-MS. Natural Product Research, pp1-8, 2017. (Impact Factor 1.999).
• -Ridha Ben Said, Arafa I. Hamed, Usama A. Mahalel, Abdullah Sulaiman Al-Ayed, Mariusz Kowalczyk, Jaroslaw Moldoch, Wieslaw Oleszek, Anna Stochmal (2017). Tentative Characterization of Polyphenolic Compounds in the Male Flowers of Phoenix dactylifera by Liquid Chromatography Coupled with Mass Spectrometry and DFT with Evident Free Radical Scavenging Activity. International Journal of Molecular Science, 2017, 18(3), 512-529. (5-Year Impact Factor: 4.183).
• -Ridha Ben Said, Arafa I. Hamed, Khaled Essalah, Abdullah S. Al-Ayed, Salima Boughdiri, Bahoueddine Tangour, Mariusz Kowalczyk, Jaroslaw Moldoch, Usama A. Mahalel, Wielsow Oleszek, Anna Stochmad (2017). Fast characterization of C-glycoside acetophenones in Medemia argun male racemes (an Ancient Egyptian palm) using LC-MS analyses and computational study with their antioxidant effect. Journal of Molecular Structure, 1145: 230-239. (Impact Factor: 2.120).
• -Sabry A. El-Naggar, Usama A. Mahalal, Ibrahim B. Abel-Farid (2017). Phytochemical analysis and anticancer activity of some medicinal plants grown in the Kingdom of Saudi Arabia. Pakistan Journal of Pharmaceutical Sciences, (Impact Factor 0.596).

2016

• -Masulloa M., Hamed, I.A., Usama A. Mahalel, Pizzaa C., Piacente S. (2016). Phenolic Compounds from the Fruits of Medemia argun, a Food and Medicinal Plant of Ancient Egypt. Natural Product Communications, 11: 279-282. (5 Year Impact Factor: 0.554).
• -Abdel-Farid I.B., Usama A. Mahalel, Jahangir M., Elgebaly A.H., El-Naggar1 A.S. (2016). Metabolomic profiling and antioxidant activity of Opophytum forsskalii. Aljouf University Science and Engineering Journal, 3: 19-24.

2015

• -Elamir M.F. Hegazy, Tarik A. Mohamed, Abdelsamed I. ElShamy, Abou-El-Hamd H. Mohamed, Usama A. Mahalel, Eman H. Reda, Alaa M. Shaheen, Wafaa A. Tawfik, Abdelaaty A. Shahat, Khalid A. Shams, Nahla S. Abdel-Azim, Fayza M. Hammouda (2015). Microbial biotransformation as a tool for drug development based on natural products from mevalonic acid pathway: A review. Journal of Advanced Research, 6: 17–33. (Impact factor: 5.045).
• -Usama A. Mahalel (2015). Allelopathic effect of saponins isolated from Trigonella hamosa L. and Solanum lycopersicum L. on germination and growth of Allium cepa L. Catrina Journal, 12: 95 -99.

2014

• -Hamed A.I., Masullo M., Pecio L., Gallotta D., Usama A Mahalel, Pawelec S., Stochmal A., Piacente S. (2014). Unusual Fernane and Gammacerane Glycosides from the Aerial Parts of Spergula fallax. Journal of Natural Products, 77: 657-62. (Impact Factor: 4.257).

2012  

• -Hamed A.I., Janda B., Usama A. Mahalel, Stochmal A., Oleszek W. (2012). Profiles of Steroidal Saponins from the Aerial Parts of Tribulus pentandrus, T. megistopterus subsp. pterocarpus and T. parvispinus by LC-ESI-MS/MS. Phytochemical Analysis 23, 613-21. (Impact Factor: 1.693).
• -Hamed A.I., Perrone A., Usama A. Mahalel, Oleszek W., Stochmal A., Piacente S. (2012). Oleanane glycosides from the roots of Alhagi maurorum. Phytochemistry Letters, 5:782-787. (5-Year Impact Factor: 1.338).

2011

• -Maldinia M., Montoroa P., Hamed A. I., Usama A. Mahalel. Oleszek W., Stochmal A., Piacente S. (2011) Strong antioxidant phenolics from Acacia nilotica: Profiling by ESI-MS and qualitative–quantitative determination by LC–ESI-MS. Journal of Pharmaceutical and Biomedical Analysis 56, 228– 239. (Impact Factor: 2.983)
• -Hamed A.I., Masullo M, Sheded M.G., Usama A. Mahalel. Tawfik M. A., Perrone A., Piacente S. (2011) Triterpene saponins from Salsola imbricate. Phytochemistry Letters 4, 353-356. (Impact Factor: 1.338).
• -Bakheet S. H.M., Abdel-Motaal F.F., Usama A. Mahalel. (2011). Antifungal effects of Ficus sycomorus and Pergularia tomentosa aqueous extracts on organs in Bufo regularis treated with Aspergillus niger. Tissue and Cell, (43): 398-404. (Impact Factor: 1.553).
• -Usama A. Mahalel (2011) Antibacterial sensitivity for some chemically diverse steroidal glycosides in vitro. Journal of Agriculture and Social Science, 8:24:28.

2007

• -Alaa El-Din Salah, Usama A. Mahalel and Hamed A.I. (2007) Protective Role of Trigonella hamosa Saponins Against Diabetic Perturbations and Complications in Rats. Natural Product Communications (NPC), (2): 811-816. (Impact Factor: 0.554).
• -Mohamed-Elamir F. Hegazy, Abou El-Hamd H. Moahmed, Fayza M. Hammouda, Nahed M.Hassan, Usama A. Mahalel, Ali M. El-Halawany,  Ahmed A. Mahmoud,  Joe Karchesy, Toshifumi Hirata and Ahmed A. Ahmed (2007): Genus Chrysothamnus: a source of bioactive  compounds. Natural Product Communications (NPC), (2): 951-975. (Impact Factor: 0.554).

2006

• -Hamed A. I., Plaza A., Usama A. Mahalel. Springuel I. Oleszek W., Pizza C. and Piacente S. (2006): Cardenoloide Glycosides from Pergularia tomentosa and their proapoptotic activity in Kaposis Sarcoma cells. Journal of Natural Products.69:1319-1322. (Impact Factor: 4.257)
• Usama A. mahalel, Mahmoud F. M. Moustafa and Soad El-Zayat (2006): Biodetermination of saponins by using Trichoderma viride. Journal of Catrina (2):33-36.

2000

• -El-Otify A.M. and Usama A Mahalel (2000): Ecological Studies on the soil algae of Wadi Allaqi Biosphere Reserve area in Southern Desert, Egypt. Journal of Phycol. Vol. (1):107-119.