Tissue-specific and maturity-dependent distribution of pyridine alkaloids in Areca triandra

Areca nuts (seeds of Areca catechu L.) are a traditional and popular masticatory in India, Bangladesh, Malaysia, certain parts of China, and some other countries. Four related pyridine alkaloids (arecoline, arecaidine, guvacoline, and guvacine) are considered being the main functional ingredients in areca nut. Until now, A. catechu is the only known species producing these alkaloids in the Arecaceae family. In the present study, we investigated alkaloid contents in 12 Arecaceae species and found that only Areca triandra Roxb. contained these pyridine alkaloids. We further analyzed in more detail tissue-specific and development-related distribution of these alkaloids in leaves, male and female flowers and fruits in different stages of maturity in A. triandra by ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry. Results revealed that the alkaloids were most abundant in young leaves, the pericarp of ripe fruits and the endosperm of unripe fruits in developmental stage 2. Abundance of the 4 different alkaloids in A. triandra fruits varied during maturation. Pericarps of ripe fruits had the highest arecaidine concentration (4.45 mg g^-1) and the lowest guvacoline concentration (0.0175 mg g^-1), whereas the endosperm of unripe fruits of developmental stage 2 contained the highest guvacoline concentration (3.39 mg g^-1) and the lowest guvacine concentration (0.245 mg g^-1). We conclude that A. triandra is useful in future as a further valuable source of Areca alkaloids.