depending on the purpose, if you plan to develop it as food supplement then usually is not patented; if you plan to develop it as a modern drug, i.e., a pure chemical entity, then follows the international patent law. If it is a mixture extract, it may be difficult to patent it.
I'll give an example of Taxol, the cancer drug first isolated from the Pacific Yew tree. You can either describe the chemical substance and the steps required to extract and purify it for use (method of use), or describe how you alter a naturally-occurring substance for a new, not found in nature, chemical entity (adding a CH3- or Pegylation). This would be a new composition of matter patent. Either way, you need a patent attorney eventually.