Genetic diversity and camphor profiling of Curcuma caesia roxb.: identification of elite genotypes and in silico prediction of gastroprotective mechanisms.

Curcuma caesia Roxb (Black Turmeric) is an underexploited medicinal species with recognized ethnobotanical use in gastrointestinal disorders. This study integrates morphological characterization, validated camphor quantification, and computational anti-ulcer evaluation across 21 genotypes collected from diverse Indian agro-climatic zones. Genotypes were cultivated at Coimbatore and Bhavanisagar and characterized using DUS guidelines. Significant morphological variation was observed in plant height (27.81-107.08 cm), rhizome traits, and essential oil yield (0.20%-0.62%), indicating high genetic diversity. GC-MS profiling identified 30 bioactive metabolites, with camphor emerging as the predominant constituent. Quantification using D-camphor standard revealed substantial genotypic variation in camphor content, ranging from 5.19% (GKK-6) to 33.84% (GTE-18), with high concentrations also recorded in GMR-2 (30.35%), GMN-10 (26.41%), and GCA-5 (24.44%). Molecular docking studies against ulcer-associated targets predicted camphor's superior binding affinity for MMP9 (-7.8 kcal/mol) compared to ranitidine (-6.3 kcal/mol), with stable hydrogen bonding interactions involving TYR A:111 and TYR A:458. Molecular dynamics simulations over 100 ns confirmed stable camphor-MMP9 interactions with minimal RMSD deviation (0.20-0.25 nm) and persistent hydrogen bonding, providing computational support for investigating its potential gastroprotective role in mucosal healing. While in silico predictions suggest plausible mechanisms aligning with traditional ethnomedicinal use, these computational findings require experimental validation through in vitro enzyme inhibition assays and in vivo gastric ulcer models. This study provides a phytochemical and computational foundation for hypothesis-driven investigation of camphor's potential gastroprotective properties, identifying elite C. caesia genotypes (GTE-18, GMR-2, GMN-10) for breeding programs targeting enhanced camphor content and subsequent biological validation.