New novel both are same at first look but to be more precise say in the case of natural products novel emphasise more on the integrity & unusuality for a class or some structural uniqueness or isolated as different chemical entity from a natural resource for the first time then that will fit the word "NOVEL" as something unique otherwise conventional "NEW".
A Novel Compound is any chemical entity that 1) has never been tested in animals; or 2) is
in preliminary stages of animal testing. Novel Compound status affects the evaluation of a compound for potential for adverse side effects and the animal monitoring intensity level. Novel Compound status will continue until the PI has collected a reasonable amount of data from observing animals at the maximum dose of a novel compound. If, at this stage, no adverse effects have been found, increased frequency monitoring can be reduced. If adverse effects have been found, monitoring will continue at a level necessary to prevent unnecessary pain or distress.
My previous comments applied to general usage of words like new, novel, innovation. It looks as if someone has now defined a new and specialized usage for the term Novel Compound.
Novel compounds are those which have not yet been discovered by either isolation and characterisation.
New compounds are those which have been discovered and then tested out with the current or existing compounds to find out whether they have similar properties.
A Novel Drug or a New Molecular Entity (NME) is an active compound, complex, molecule that previously has not been approved by the FDA/EMA. A Novel Drug or a New Molecular Entity (NME) is an active compound, complex, molecule that previously has not been approved by the FDA/EMA.
Novel compound means, it is not discovered in past and possess special or enhanced properties in specific field.
A new compound means it is just another chemical compound with different composition (not established previously) for addressing same problem with few advantages.,
Because there are many meanings and usages of the words 'novel and new', one must define before using them. In the case of the isolation and structure determination of natural products, a novel compound is one whose structure was discovered for the first time ever. A new compound is one whose structure has been discovered but was discovered for first time in a particular producer organism or genera. (I hope this has been helpful.)