Aloe vera: Quantification of key metabolites for identity and quality assessment

Aloe vera is a medicinal plant with a wide range of uses from topical application to soothe burns to oral consumption to aid digestion. It is added to a wide range of health and beauty products. The quality and safety of dietary supplements has been emphasized since the 2007 FDA cGMP ruling, which states that manufacturers must ensure identity, purity, strength, and composition of their products. Botanical material is highly variable depending on species and growing conditions which make evaluation of these materials challenging. For analyzing Aloe vera extract in detail, components include glucose, acetylated mannose polymers, and malic acid. As the material ages, degradation products include acetic acid, lactic acid, formic acid, and fumaric acid. Common additives include the preservatives sodium benzoate and potassium sorbate. Depending on the formulation, other additives such as glycerol may be present. Nuclear magnetic resonance spectroscopy provides an effective means of evaluating botanical material as a result of its ability to be used as (1) a fingerprinting tool and (2) for quantitative analysis. Presented here is the implementation of a ¹H-NMR spectroscopy-based method [1] to evaluate Aloe vera in the Assure-RMS software package to provide a fully automated analysis of Aloe vera samples. The automated analysis will be described, first presenting the readily quantitated components, emphasizing the features of the spectra of these components that lend themselves to robust analysis. Then more problematic components will be examined. Strategies to improve the quantitation, including additional data and more sophisticated analysis, will be discussed.

References: [1] Jiao et al. (2010)J. of the AOAC International, Vol. 93, p 842–848.