It depends on the plant species and the contained phytochemicals.

I.e. for Hypericum I would use hypericin, hyperforin and phloroglucinols and flavonoids common in species of this genus. If you plan to analyse a Gentiana the choice may fall to secoiridoids (i.e gentiopicroside, swertiamarin) and xanthones.

The standards selected are the possible compouds from you extract. You use them to confirm the presence of this compounds.

Regards

G.

Thanx Alessandro Venditti and Grzegorz Boczkaj for your nice answers.

Actually I want to perform HPTLC fingerprinting of some parts of Dioscorea bulbifera. Can you Please suggest something regarding the same

Dear Musadiq please find attached file may be helpfual for you.

The seroid diosgenin is the best known constituent of this species but also other classes of natural products have been identified such as saponins, phenolics (flavonoids, phenolic acids, diphenylethanoids, arylheptanoids, phenanthrene derivative, etc), diterpenoids. It depends also on the plant organs you want to analyse.

It is possible that several of these compounds are not commercial therefore you should purify them (and identifiy with suitable methods) to have the necessary standards. The following papers may be useful to have an idea about the phytochemicals contained in this apecies.

Tapondjou, L.A., et al., 2013. Steroidal saponins from the flowers of Dioscorea bulbifera var. sativa. Phytochemistry, 95, pp. 341-350.

Liu, H., et al., 2011. Phenolic compounds from the rhizomes of dioscorea bulbifera. Chemistry and Biodiversity, 8(11), pp. 2110-2116.

Kuete, V., et al., 2012. Antibacterial activities of the extracts, fractions and compounds from Dioscorea bulbifera. BMC Complementary and Alternative Medicine, 12,228.

Liu, H., et al., 2010. Norclerodane diterpenoids from rhizomes of Dioscorea bulbifera. Phytochemistry, 71(10), pp. 1174-1180.

Shi, W., et al., 2018. Metabolism of five diterpenoid lactones from: Dioscorea bulbifera tubers in zebrafish. RSC Advances, 8(14), pp. 7765-7773.

Phytochemical reference standards (PRS) should have uniform distribution with or without biological activity. this is the criteria for selection.

its uniform distribution will help taxonomically identification and quality control purposes.

Secondary metabolites are diverse, it depend on what you are targeting. You need to do literature searching to find the most predominant compounds in the plant that you are working on. However, there are few metabolites that are common to many plants e.g Quercetin, Rutin, Gallic acid