Natural preservative, Purinol™
Magnolia officinalis bark has been used for an important ingredient in traditional medicine system of Asia. The main ingredients are two biphenolic compounds, magnolol and honokiol, which have been reported to have various biological activities .
We have studied natural anti-microbial products and developed, Purinol™, a standardized composition with magnolol and honokiol at a 1:1 ratio from Magnolia officinalis bark. Purinol™ was evaluated for its anti-microbial activity against Staphyllococcus aureus, Propionibacterium acne, Candida albicans, Aspergillus niger and Tricophyton metagrophytes  and showed strong MIC (minimum inhibitory concentration) value at 10 (S. aureus), 10 (P. ance), 20 (C. albican), 40 (A. niger) and 4 (T. metagrophytes) µg/ml respectively. All tests showed 5˜200 times higher antimicrobial activity than methyl paraben and similar activity to erythromycin and amphotericin.
The Purinol™ was also evaluated by human primary irritation test at 1.0% topical application and was shown to be safe without any irritancy.
References: 1. BeomSeok, C. et al. (1997) Planta Med. 64: 367–369
2. Park, J. et al. (2004) Eur J Pharmacol. 496(1–3):189–195