Title: Hyoscyamine
CAS Registry Number: 101-31-5
CAS Name: [3(S)-endo]-a-(Hydroxymethyl)benzeneacetic acid 8-methyl-8-azabicyclo[3.2.1]oct-3-yl ester
Additional Names: 1aH,5aH-tropan-3a-ol(-)-tropate (ester); 3a-tropanyl S-(-)-tropate; l-tropic acid ester with tropine; l-tropine tropate; daturine; duboisine; l-hyoscyamine
Trademarks: Cystospaz (Alcon); Levsin (Kremers-Urban)
Molecular Formula: C17H23NO3
Molecular Weight: 289.37
Percent Composition: C 70.56%, H 8.01%, N 4.84%, O 16.59%
Literature References: Anticholinergic. From Hyoscyamus niger L., Atropa belladonna L., Datura stramonium L., and other Solanaceae: Ladenburg, Ann. 206, 274 (1881). Identity with duboisine and daturine: Beckurts, Apoth. Ztg. 27, 683 (1912). Obtained by resolution of atropine: Werner, Miltenberger, Ann. 631, 163 (1960). Prepd from (-)-acetyltropoyl chloride and atropine hydrochloride: Fodor et al., Acta Chim. Acad. Sci. Hung. 28(4), 409 (1961), C.A. 61, 1903g (1964). Configuration: Fodor, Csepreghy, Tetrahedron Letters no. 7, 16 (1959). Comprehensive description: F. J. Muhtadi, Anal. Profiles Drug Subs. Excip. 23, 153-228 (1994).
Properties: Silky, tetragonal needles from evaporating alc. Keep well closed and protect from light and heat; easily racemized. mp 108.5°. [a]D20 -21.0° (alc). pKa (21°) 9.7. One gram dissolves in 281 ml water (pH 9.5), 69 ml ether, 150 ml benzene, 1 ml chloroform. Freely sol in alcohol, dil acids. uv max (methanol): 247, 252, 258, 264 nm (A1%1cm 5.18, 5.70, 6.12, 5.10). Absorption spectra: Dobbie, Fox, J. Chem. Soc. 103, 1194, 1195 (1913).
Melting point: mp 108.5°
pKa: pKa (21°) 9.7
Optical Rotation: [a]D20 -21.0° (alc)
Absorption maximum: uv max (methanol): 247, 252, 258, 264 nm (A1%1cm 5.18, 5.70, 6.12, 5.10)
Derivative Type: Hydrobromide
CAS Registry Number: 306-03-6
Molecular Formula: C17H23NO3.HBr
Molecular Weight: 370.28
Percent Composition: C 55.14%, H 6.53%, N 3.78%, O 12.96%, Br 21.58%
Properties: Deliquescent crystals, mp 152°. pH 5.4 (1 in 100). Levorotatory. Very sol in water. One gram dissolves in 3 ml alcohol, 1.2 ml chloroform, 2260 ml ether.
Melting point: mp 152°
Derivative Type: Hydrochloride
Molecular Formula: C17H23NO3.HCl
Molecular Weight: 325.83
Percent Composition: C 62.67%, H 7.42%, N 4.30%, O 14.73%, Cl 10.88%
Properties: Crystals. Poisonous! mp 149-151°. Freely sol in water, alcohol.
Melting point: mp 149-151°
Derivative Type: Methyl bromide
Additional Names: N-Methylhyoscyaminium bromide
Molecular Formula: C17H23NO3.CH3Br
Molecular Weight: 384.31
Percent Composition: C 56.25%, H 6.82%, N 3.64%, O 12.49%, Br 20.79%
Properties: Crystals, mp 210-212°. Freely sol in water, dil alc; slightly sol in abs alc.
Melting point: mp 210-212°
Derivative Type: Sulfate dihydrate
CAS Registry Number: 6835-16-1
Trademarks: Egacene; Egazil Duretter; Peptard (3M Pharma)
Molecular Formula: (C17H23NO3)2.H2SO4.2H2O
Molecular Weight: 712.85
Percent Composition: C 57.29%, H 7.35%, N 3.93%, O 26.93%, S 4.50%
Properties: Needles from alcohol, mp 206° when dry. [a]D15 -29° (c = 2). pH 5.3 (1 in 100). One gram dissolves in 0.5 ml water, about 5.0 ml alcohol. Very slightly sol in chloroform, ether.
Melting point: mp 206° when dry
Optical Rotation: [a]D15 -29° (c = 2)
Therap-Cat: Antispasmodic.
Keywords: Antimuscarinic; Antispasmodic.
Hyoscyamus Hypalon? Hypaphorine Hypochlorous Acid Hypoglycine A

Systematic (IUPAC) name
(8-methyl-8-azabicyclo[3.2.1]oct-3-yl) 3-hydroxy-2-phenylpropanoate
Clinical data
Trade names Anaspaz, Levbid, Levsin
AHFS/Drugs.com monograph
MedlinePlus a684010
Pregnancy cat. C
Legal status Prescription Only (S4) (AU) Prescription only (US)
Routes Oral, Injection
Pharmacokinetic data
Bioavailability 50% Protein binding
Metabolism Hepatic
Half-life 3–5 hrs.
Excretion Urine
CAS number 101-31-5 YesY
ATC code A03BA03
PubChem CID 154417
DrugBank DB00424
ChemSpider 10246417 YesY
ChEBI CHEBI:17486 YesY
Chemical data
Formula C17H23NO3 
Mol. mass 289.375 g/mol
 N (what is this?)  (verify)

Hyoscyamine (also known as daturine) is a tropane alkaloid. It is a secondary metabolite found in certain plants of the Solanaceae family, including henbane (Hyoscyamus niger), mandrake (Mandragora officinarum), jimsonweed (Datura stramonium), tomato (Solanum lycopersicum) and deadly nightshade (Atropa belladonna). It is the levorotary isomer of atropine (third of the three major nightshade alkaloids) and thus sometimes known as levo-atropine. Hyoscyamine should not be confused with hyoscine, an older alternate name for the related nightshade-derived anticholinergic scopolamine for which it is the precursor.

Brand names for hyoscyamine include Symax, HyoMax, Anaspaz, Egazil, Buwecon, Cystospaz, Levsin, Levbid, Levsinex, Donnamar, NuLev, Spacol T/S and Neoquess.