For chemical defence against herbivores, Calotropis has

Calotropis, also known as milkweed or rubber bush, is a plant species that possesses chemical defence mechanisms
Against herbivores. Calotropis produces toxic secondary metabolites called cardiac glycosides. They affect the heart and can be harmful to animals, if ingested. They interfere with the functioning of the heart by inhibiting the activity of the sodium-potassium ATPase. This disruption can lead to cardiac arrhythmias and other adverse effects, potentially deterring herbivores from consuming Calotropis.
(2) Strychnine is a highly toxic alkaloid that is found in certain plant species, particularly in the Strychnos genus.
Strychnine acts as a neurotoxin, affecting the central nervous system, but it is not the chemical defense mechanism of Calotropis.
(3) Ricin is a highly toxic protein that is derived from the seeds of the castor oil plant (Ricinus communis). Ricin inhibits
Protein synthesis within cells, leading to cell death.
(4) Quinine is a bitter-tasting alkaloid that is naturally present in certain plant species, such as the Cinchona tree. It is
Commonly known for its use in treating malaria.