Exploring Steroidal Saponin Composition and Morphometric Characteristics of Rhizomes from Trillium govanianum Wall. ex D. Don: Inference for Medicinal Properties and Genetic Stock Improvement.

Abstract

Trillium govanianum, a medicinal herb, exhibiting diverse morphometric traits and phytochemicals across developmental stages of plants. The changes in the chemical profile and steroidal saponin levels in the rhizome of T. govanianum across different developmental stages were previously unknown. This study categorizes rhizomes into three types based on scar presence: juvenile (5-10 scars, Type I), young (11-19 scars, Type II), and mature (21-29 scars, Type III). Rhizomes show varying sizes (length 1.2-4.7 cm, girth 0.3-1.6 cm), weight (0.18-5.0 g), and extractive yields (9.7-16.1 % w w-1), with notable differences in saponin content (5.95-21.9 mg g-1). Ultra-high performance liquid chromatography-MS/MS (UHPLC-QTOF-MS/MS)-based chemical profiling identifies 31 phytochemicals, mainly including diverse saponins. Ultra-high performance liquid chromatography coupled with evaporative light scattering detection (UHPLC-ELSD)-based quantitative analysis of seven key saponins reveals stage-specific accumulation patterns, with protodioscin (P) and dioscin (DS) predominant in mature rhizomes. Statistical analysis confirms significant variation (p=0.001) in saponin levels across developmental stages with chemical constituent protodioscin (P=4.03±0.03-15.76±0.14 mg g-1, PAve=9.79±3.03 mg g-1) and dioscin (DS=1.23±0.06-3.93±0.07 mg g-1, DSAve=2.59±0.70 mg g-1), with acceptable power (p=0.738; |δ|>0.5) statistics for effective sample size (n=27 samples used in the study) of T. govanianum. Principal Component Analysis (PCA) and Euclidean clustering further highlighted chemotype distinctions.