ABSTRACT
ABSTRACT Melatonin (N-acetyl-5-methoxytryptamine), an indole compound of tryptophan precursor, is ubiquitous in the plant kingdom. The objectives of the current study were to isolate, purify, and characterize a bioactive tryptamine derivative from Varuna (Crataeva nurvala Buch-Ham), a wellexplored traditional Indian medicinal plant with historical evidence of efcacy in the treatment of neurological and antioxidant deciency-related disorders. In this study, a chloroform fraction of C. nurvala stem bark was analyzed using column chromatography and thin-layer chromatography (TLC), which lead to the isolation of melatonin, a biogenic indoleamine. The structure of the isolated compound was determined by various spectroscopic analyses, such as ultraviolet (UV), infrared (IR), carbon nuclear magnetic resonance (13C NMR), proton nuclear magnetic resonance (1H NMR), two-dimensional correlated spectroscopy (2-D COSY), and mass spectroscopy. Mass spectroscopy of the isolated compound showed a parent molecular ion (M+) peak at m/z 233.2 g/mol, corresponding to the molecular formula C13H16N2O2. In the 1H NMR spectrum, singlet (s) at δH 3.79 corresponds to 3 H of -OCH3, multiplet (m) at δH 6.7, 7.0, 7.7 denotes 4 Ar. protons, singlet (s) at δH 1.9 is assigned to 3 H of -CH3CO, triplet (t) at δH 2.8 corresponds to 2 H of N-CH2, multiplet (m) at δH 3.27 denotes 2 H of indolyl CH2, singlet (s) at δH 10.41 is assigned to 1 H of NH indole, and singlet (s) at δH 8.01 corresponds to 1 H, NH of secondary amide. 13C NMR showed the presence of a total of 13 carbon atoms. Based on physical and spectral characteristics, the isolated compound was identied and reported for the rst time as N-acetyl-5-methoxytryptamine (melatonin) from C. nurvala. With this background, the chapter is designed to provide an overview of phytomelatonin, specically on its distribution and occurrence, isolation, and structural elucidation.
