The firms include Chinese company Fenchem Enterprises, which makes GreenShield brand beta glucan, California-based Cypress Systems, the supplier of BetaPrecise brand beta glucan, and Biotec Pharmacon and distributor of its Immutol product, Immunocorp, which is used in supplements including those marketed by Natrol.
Biothera, formerly Biopolymer Engineering, has successfully defended its patents in two previous actions against High Performance Living in 2002 and Levapan and Savoury Systems International the following year.
However Biothera president and chief executive officer Richard Mueller says patent infringements are a result of what has been, until recently, a very fragmented intellectual property landscape for the ingredient.
"The recognition of the importance of the immune system is growing rapidly and as a result the whole business of beta glucan is also growing rapidly," he told NutraIngredientsUSA.com.
"However early on there were many people involved in the R&D of beta glucan and some of the patents overlap," he added.
The firm has through two acquisitions gained a large bulk of the intellectual property on the use of beta 1,3/1,6 glucan derived from Baker's yeast (Saccharomyces cervisiae) and its use in supplements.
Mueller added that not enough attention is paid in the natural products business to "who really owns the rights to certain products".
The immune-boosting ingredient is Biothera's main source of revenue, supporting a clinical trial program for development of beta glucan-based drugs. It is currently growing by more than 300 per cent and used in a range of products including drinks.