Mixture as its melting point, may differ from those of the components. Some mixtures can be separated into their components by using physical (mechanical or thermal) means. Azeotropes are one kind of mixture that usually pose considerable difficulties regarding the separation processes required to obtain their constituents (physical or chemical processes or, even a blend of them). Mixtures can be either homogeneous or heterogeneous. A homogeneous mixture is a type of mixture in which the composition is uniform and every part of the solution has the same properties. Examples of homogeneous mixtures include alloys and alcohol in water. A heterogeneous mixture
Phomoxanthone A PXA and PXB were discovered in 2001, and their preparation by isolation from "Phomopsis" fungal cultures was described in the corresponding publication. Briefly, a MeOH extract of a "Phomopsis" culture is mixed with HO and washed with hexane. The aqueous phase is then dried and the residue is dissolved in EtOAc, washed with HO, concentrated and repeatedly purified by size-exclusion chromatography. The resulting mixture of PXA and PXB is separated by HPLC. A modified method, in which the initial extraction is done with EtOAc instead of MeOH and the drying step is skipped, was described in 2013. Phomoxanthone A was