Q.62 Identify the CORRECT combination(s) of plant natural products and the categories
they belong to.
(A) Dhurrin − Phenolic compounds
(B) Farnesene − Terpenoids
(C) Naringenin − Cyanogenic glycosides
(D) Vincristine − Alkaloids

Correct options: (B) and (D).

Farnesene belongs to terpenoids, while vincristine is an alkaloid, making these the accurate pairings among the given choices.​

Option Analysis

(A) Dhurrin − Phenolic compounds: Incorrect. Dhurrin is a cyanogenic glycoside found in sorghum, functioning as a defense metabolite that releases hydrogen cyanide upon hydrolysis, not a phenolic compound.​

(B) Farnesene − Terpenoids: Correct. Farnesene is a sesquiterpene, a class of terpenoids, present in apple coatings and essential oils, contributing to scents and acting as pheromones.​

(C) Naringenin − Cyanogenic glycosides: Incorrect. Naringenin is a flavanone flavonoid, a type of phenolic compound abundant in citrus fruits, known for antioxidant properties.​

(D) Vincristine − Alkaloids: Correct. Vincristine is a vinca alkaloid from Catharanthus roseus, used in chemotherapy for its microtubule-disrupting effects.​

Plant natural products categories play a crucial role in CSIR NET Life Sciences, helping students classify secondary metabolites like cyanogenic glycosides and terpenoids for defense, pharmacology, and ecology. These compounds, derived from biosynthetic pathways, showcase plants’ chemical diversity.​

Key Classifications

• Dhurrin: Classified as cyanogenic glycosides, not phenolics; biosynthesized from tyrosine in sorghum for herbivore deterrence via HCN release.​

• Farnesene: Terpenoid (sesquiterpene); imparts apple aroma and serves as an aphid alarm pheromone.​

• Naringenin: Flavonoid (flavanone) phenolic; offers antioxidant benefits in citrus.​

• Vincristine: Alkaloid from periwinkle; targets cancer by halting mitosis.​

Exam Relevance

In competitive exams, distinguishing plant natural products categories avoids errors—e.g., dhurrin is never phenolic, unlike naringenin. Terpenoids like farnesene arise from isoprene units.​