J. Chem Soc. Nigeria, Vol. 43, No. 4, pp 914 -921 [2018] DPPH Free Radical Scavenging Activities of Anthocleista djalonensis A. Chev and Isolation of Benzoic Acid O.O. Olubomehin 1* , E.O. Ajaiyeoba 2 , K. A. Abo 3 and E. D. Goosen 4 1 Department of Chemical Sciences, Olabisi Onabanjo University, Ago-Iwoye, Nigeria. 2 Department of Pharmacognosy, University of Ibadan, Ibadan, Nigeria 3 Department of Pharmacognosy & Phytotherapy, University of Port Harcourt, Nigeria. 4 Faculty of Pharmacy, Rhodes University, Grahamstown, South Africa. *Corresponding author: olubomehin.oseyemi@oouagoiwoye.edu.ng, +2348139619065 Received 30 Sepember 2018; accepted 28 October 2018, published online 06 November 2018 ABSTRACT Development of ethnomedicines from plants with strong antioxidant properties is increasing because reactive oxygen species (ROS) production and oxidative stress by free radicals have been linked to a number of human degenerative diseases, such as cancer, diabetes, inflammation, amongst others. Anthocleista djalonensis, used traditionally to treat diabetes, malaria, hernia, and hypertension was investigated for its free radical scavenging properties. The phytochemical screening results showed that both samples had anthraquinone derivatives. Alkaloids, saponin and flavonoids were present only in the leaves while tannins were absent in both. At 1 mg/mL, the stem bark crude extract gave an antioxidant activity of 25.42%, the leaf 4.42% while α-tocopherol gave 89.54%. Fraction C from which benzoic acid was isolated gave a 64.52% antioxidant activity. The antioxidant activity of this plant could be beneficial in the treatment of diabetes and hypertension. Different derivatives of benzoic acid from the stem bark of Anthocleista djalonesis could also be prepared and employed for antioxidant use. Keywords: Antioxidant, Anthocleista djalonensis, column chromatography, benzoic acid INTRODUCTION Reactive oxygen species (ROS) called free radicals are products of normal cellular metabolism (which can either be harmful or beneficial to the living system) and may also be introduced from the environment [1, 2]. It has been realised that many of the modern human diseases such as diabetes [3,4], Alzheimer’s disease [5], atherosclerosis [6], and cancer [7] are due to oxidative stresses initiated by free radicals [8,9]. Thus, development of ethnomedicines from plants with strong antioxidant properties has received much attention [10]. Anthocleista djalonensis A. Chev, belongs to the Loganiaceae family. It is a small candelabrum-shaped tree found in the semi-savannah tropical regions of West Africa, characterized by its inconspicuously spiny branches, secondary venation and creamy or white flowers [11, 12]. Some common vernacular names in Nigeria are ‘Kwarii’, ‘Okpokolo’ and ‘Sapo’ by the Hausa, Igbo and Yoruba respectively [13]. In Nigeria, particularly among the Ibo tribe, the seed, stem bark and root of A. djalonensis are widely used as antipyretic, laxative and remedy for various stomach disorders [14], while the Ibibios of Southern Nigeria use the leaves and stem bark as malaria remedy [15]. The root decoction of A. djalonensis and related species, A. vogelii and A. kerstingii have been used in the treatment of diabetes mellitus with a