before now, i thought pregnanes were only found as by products of progesterone metabolism by the liver. i just went through an article " Two new pregnanes from Aglaia perviridis Hiern" by Yang et al. (2008), where it is reported that pregnanes are also found in Hiern. 

1. could these two types of pregnane have the same same structure/property

2. are there other sources of pregnane

3. does this same diversity apply to pregnanediones?