The Rehmannioside A, with the CAS registry number 81720-05-0, has molecular formula C₂₁H₃₂O₁₅. Its formula weight is 524.47. What's more, its systematic name is called (1aS,1bS,2S,5aR,6S,6aS)-6-hydroxy-1a-(hydroxymethyl)-1a,1b,2,5a,6,6a-hexahydrooxireno[4,5]cyclopenta[1,2-c]pyran-2-yl 6-O-α-D-galactopyranosyl-β-D-glucopyranoside.

Physical properties of Rehmannioside A: (1)ACD/LogP: -3.77; (2)# of Rule of 5 Violations: 3; (3)ACD/LogD (pH 5.5): -3.77; (4)ACD/LogD (pH 7.4): -3.77; (5)ACD/BCF (pH 5.5): 1; (6)ACD/BCF (pH 7.4): 1; (7)ACD/KOC (pH 5.5): 1; (8)ACD/KOC (pH 7.4): 1; (9)#H bond acceptors: 15; (10)#H bond donors: 9; (11)#Freely Rotating Bonds: 16; (12)Index of Refraction: 1.692; (13)Molar Refractivity: 112.92 cm³; (14)Molar Volume: 294.6 cm³; (15)Surface Tension: 109.1 dyne/cm; (16)Density: 1.78 g/cm³; (17)Flash Point: 478.1 °C; (18)Enthalpy of Vaporization: 143.17 kJ/mol; (19)Boiling Point: 867 °C at 760 mmHg; (20)Vapour Pressure: 4.54E-35 mmHg at 25°C.

You can still convert the following datas into molecular structure:
(1)SMILES: O(C[C@H]4O[C@@H](O[C@@H]3O\C=C/[C@H]2[C@H](O)[C@@H]1O[C@]1(CO)[C@H]23)[C@H](O)[C@@H](O)[C@@H]4O)[C@H]5O[C@@H]([C@H](O)[C@H](O)[C@H]5O)CO
(2)InChI: InChI=1/C21H32O15/c22-3-7-11(25)13(27)15(29)19(33-7)32-4-8-12(26)14(28)16(30)20(34-8)35-18-9-6(1-2-31-18)10(24)17-21(9,5-23)36-17/h1-2,6-20,22-30H,3-5H2/t6-,7-,8-,9-,10+,11+,12-,13+,14+,15-,16-,17+,18+,19+,20+,21-/m1/s1
(3)InChIKey: DTNSOISBYQKHCS-XTOBSYSVBN