Secondary Metabolite Dynamics in <i>Datura stramonium:</i> Integrated Histochemistry, Gas Chromatography–Mass Spectrometry Analysis, and Quantitative Assessment

Datura stramonium exhibits broad pharmaceutical significance due to its secondary metabolites. The present study investigates the localization of secondary metabolites in Datura stramonium during growth stages from germination to fruiting through histochemical and quantitative approaches, complemented by GC–MS analysis. Alkaloids were detected in the mesophyll of leaves, outer phloem of stems and roots, and endodermis of roots, extending to vessel walls and xylem fibers. Notably, the flowering stage exhibited a pronounced accumulation of alkaloids in the xylem parenchyma of leaves and stems and in the stem pith. As the secondary growth developed in the root at the second month and in the stem at the third month, alkaloids became evident in the medullary rays. In the stem, significant alkaloid accumulation occurred in the inner phloem at flowering and fruiting stages. Flavonoids were traced in the mesophyll and xylem parenchyma of leaves throughout growth, while phenolics were localized in the mesophyll and idioblasts of the midrib in the fruiting stage. Quantitative estimations revealed the highest concentrations of alkaloids, flavonoids, and phenolics in the leaves during the flowering stage, while the fruits exhibited the highest alkaloid content in the fruiting stage. Twenty‐two alkaloids were identified in Datura stramonium organs during different growth stages using GC–MS analysis. The identified alkaloids belonged mainly to the tropane class, with minor contributions from piperidine, pyrrolidine, and steroidal alkaloids. Alkaloid composition varied among plant organs and developmental stages, with atropine and hyoscine as the dominant compounds. Also, monitoring alkaloidal content changes through GC–MS suggested the possible presence of a biosynthetic pathway for tropacocaine in Datura stramonium . Tropacocaine exhibited central nervous system activity as an anesthetic, so it is used principally in spinal anesthesia. These findings enhance our understanding of spatial and temporal dynamics, time‐course deposition and development of secondary metabolites, aiding in maximizing therapeutic efficacy.