Patterns of Biflavonoid Accumulation in Ginkgo (Ginkgo biloba L.) Leaves from 90 Trees and Their Variation with Age, Gender, and Location

Biflavonoids are dimeric flavonoids recognized for their diverse biological activities and significant pharmacological potential, with ginkgo (Ginkgo biloba L.) serving as a primary natural source. This study presents a comprehensive spatiotemporal characterization of the biflavonoid profile across a diverse population of 90 trees. High-resolution chromatographic analysis quantified five major biflavonoids, revealing a consistent hierarchical abundance: sciadopitysin > isoginkgetin > ginkgetin > bilobetin > amentoflavone. Notably, sciadopitysin emerged as the predominant constituent (1532.89 ± 544.13 µg/g dw). To decode the complex drivers of metabolite accumulation, we integrated Principal Component Analysis (PCA) with Piecewise Linear Regression (PLR). PCA confirmed a robust chemical structure, explaining 71.5% of the total variance, where Factor 1 represents a general biflavonoid gradient and Factor 2 captures localized environmental influences. The PLR models (R2 = 0.75–0.83) identified tree age as a primary negative regulator, showing a significant decline in total biflavonoids as trees mature beyond the 30-year reproductive threshold. While sexual dimorphism and location exhibited compound-specific nonlinear effects, younger trees (10–30 years) demonstrated the highest biosynthetic plasticity and potency. These findings establish a predictive framework for optimizing the pharmaceutical harvest of ginkgo leaves, highlighting that age-related physiological shifts, rather than gender or broad geography, are the critical determinants of biflavonoids yield.