By Dr. Qi Jia
Univera Pharmaceuticals, Inc.

In recent years, Aloe vera and related products have drawn a great attention from cosmetic, nutroceutical and pharmaceutical industries. Aloe vera gel, which is generated in the mucilaginous cells of the inter central zone of the leaf, has been very well documented for its wound-healing¹, anti-inflammatory^2,3 and immune-stimulatory⁴ activities. However, the small organic compounds, which predominantly exist in the pericyclic cells underneath the leaf skin, have been ignored as impurities due to their color and gastrointestinal irritation. Because of low gel production or lack of understanding of chemistry and pharmacology, only a handful of aloe species out of more than 300 total breeds are commercially utilized.

Decades of scientific studies on Aloe chromones reveal hundreds of structures with anti-inflammation⁵, anti-ulcer⁶, tyrosinase inhibition⁷, skin protection⁸, laxative effect⁹ and other biological activities. Analyses of aloe chromones in different aloe species also have been reported^10,11.

The scientific investigation conducted in UPI is to discover new chemicals with anti-inflammation and other therapeutical potentials, to fully utilize natural aloe materials, and to explore new usage for diversified Aloe species.

Five representative compounds were isolated as QC and biolocial study standards from three different species of Aloe by using preparative HPLC, CCC and other routine chromatography methods: Aloesin (I), Aloeresin A (II), and Barbaloin (IV) from dried latex of the leaves of A. ferox, Aloenin (III) from dried whole leaves of A. arborescens and Aloeresin E (V) from the dry rind of A. The purity and chemical structures of the chromones were confirmed by HPLC and spectroscopic methods.

Thirty five Aloe plants were harvested from Koniff Nursery. Fresh collected aloe leaves were chopped to small pieces and freeze-dried. The dry leaves were ground and extracted by following the standard extraction protocol. The chromone contents in the methanol extracts were analyzed with HPLC. In-vitro anti-inflammatory assays are conducted on the alcohol and aqueous extracts. The bioasssay results and phytochemical studies of representative aloe species will be discussed in detail.

The manufacturing process of bioactive chromones from different aloe species has been developed efficiently and economically in UPI. Large-scale isolation of anti-inflammatory minor component - Aloeresin E is one of the examples¹². The pilot scale process started with extraction of 22.4 kg of Aloe vera dry rind. The exclusive technology in UPI allowed 20-fold enrichment of Aloeresin E from crude extract. A simple filtration followed by solvent partition further removed 75% of remaining impurities. After column chromatography, the compound reached supreme purity.

In conclusion, Aloe chromones are important bioactive components in natural sources. A comprehensive study could introduce new raw materials for manufacturing of bioactive chromones, could reveal a unique chemical content for further investigation, and could lead the discovery of new therapeutic agents with bioassay directed isolation. Consequently, it would convey more understanding and appreciation of the natural wonder-Aloe.

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