Each plant has a unique composition of compounds. The main compounds present in a plant are carbohydrates, terpenoids, alkaloids, steroids, chlorophylls, carotenoids, phenolic compounds like flavonoid pigments, organic acids, lipids, amino acids etc. 

For your species you first prepared extracts using solvents of different polarity then perform qualitative tests to know the class of compounds present in your sample. For this use can read my papers too. Hope it will be helpful to you.

Thanks Vinesh!

The HPLC-DAD-ESI/MS(n) analysis of Jacaranda caroba revealed the presence of four dicaffeoyl acid derivatives and nine flavonoids, comprising quercetin, kaempferol and isorhamnetin derivatives. Twelve compounds are isolated from Jacaranda genus. Although isorhamnetin-3-O-rhmanoside-7,4'-di-O-glucoside and quercetin-3-O-(2-pentosyl)hexoside are the main metabolites in both aqueous and hydromethanolic extracts.  Calendula officinalis contains saponins, polyphenols, chlorophyll, flavonoids resins, and essential oils.

Thanks Ravi! Very interesting you answer.

Dear Paula Rodrigues Fontes de Sousa Moraes

Please find important literature related with your query.

Thanks

http://www.ncbi.nlm.nih.gov/pubmed/23524314

Dear Neeraj,

thank you so much!!!

Dear Paula

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Kindly see the following RG links.

Article Calendula Officinalis-An Important Medicinal Plant with Pote...

Article Evaluation of Biologically Active Compounds from Calendula o...

Article Phenolic compounds from Jacaranda caroba (Vell.) A. DC.: App...