title: Reduction of andrographolide and its stereostructure by NMR and X-ray study.
abstract: Andrographolide (1) on asymmetric reduction with nickel boride in situ led to the identification of a product as 12,13 R-dihydroandrographolide (3) in de (>96%). The structure and stereochemistry of compound 3 were established by NMR study and confirmed by X-ray crystallographic analysis. β-Substituent of γ-butyrolactone in andrographolide exerted diastereomeric selectivity in reduction. Neoandrographolide (2) under similar condition yielded 5.
authors.affiliation: Phytochemistry Division, Central Institute of Medicinal and Aromatic Plants, Lucknow, Uttar Pradesh, India.
authors.forename: Deepika
authors.initials: D
authors.lastname: Singh
authors.forename: Prabir K
authors.initials: PK
authors.lastname: Chaudhuri
mesh_terms: D018360:Crystallography, X-Ray; D004224:Diterpenes / Q000032:analysis*; D005960:Glucosides / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013764:Tetrahydronaphthalenes / Q000032:analysis*
chemical_list: D004224:Diterpenes; D005960:Glucosides; D013764:Tetrahydronaphthalenes; C030419:andrographolide; C082497:neoandrographolide