Surprised that one has answered your post.
These are all organic substances that provide sugars, growth regulators, vitamins, nutrients etc. Though not consistent in analysis has been very useful in the culture of many orchids. You can look at the book by Arditti (Microprogatation of Orchids) it has portions on the basic analysis of some of these.
Just consider what human and animals get from eating these stuff! Though plants have a different set of essential requirements, there are some similarities.