Anatomical and Chemical Analysis of Moringa oleifera Stem Tissue Grown under Controlled Conditions

Abstract

Moringa oleifera is a relatively well-studied ethnobotanical species, but information is limited regarding its stem anatomy and the production potential of phytochemicals from bark tissue. Knowing that variation exists in the production of chemical defenses by plants with growing conditions and with developmental stages, M. oleifera was grown under controlled conditions to characterize stem tissues and to determine if stem bark contained the correct phytochemical compounds to be of value in medicinal treatments. We used microscopy to characterize the stem anatomy of M. oleifera and analyzed stem bark extracts using FTIR and GC to identify 4-(α-L-rhamnosyloxy)-benzyl isothiocyanate (moringin) and benzylamine (moringine) in tissue. We found the stems to be in transition between juvenile and mature stages of development at 4 months old under the growth conditions used. In 7-month-old stems, we found the presence of moringin in all bark samples and did not find any moringine. These results indicate that M. oleifera bark of 7-month-old trees grown in greenhouse conditions may be valuable for drug development.