can you give specific example of a biological-based chemical
One good example for biological based chemical that we normally use is ethanol. C2H5OH.
Ethanol can be produced by a variety of biological sources. The ancient method was to ferment the sap from the plants like coconut and other related trees.
But nowadays ethanol is widely produced by using malt, rice and sugar cane, those ethanol are for drinking as a beverage. But as you might be aware of there is bioethanol which is used as fuel.
Bioethanol is produced mainly by using corn, biological wastes such as rice straw and corn stover.
Biologically based chemicals are the venom's, toxins and poisons that come from the bodies of living things like animals, insects and plants.
A specific example of such is Batrachotoxin produced by the (Phyllobates terriblis) dart frog. Epibatibine is also from a frog, the Ecuadorian tree frog.
Latrodectism is the poisoning from the black willow spider. Leiurus quinquestriatus hebraeus a scorpion injects into it's prey Charybdotoxin.
There are many other living things that have poisons. Like snakes, lizards, other frogs, many insects and plants like poison ivy.