Couple of
research groups have tried to identify the prominent phenolic compounds present
in the areca nut. Considering the fact that most of the phenolic compounds
present in areca nut are structurally similar to each other and exhibit similar physico-chemical
properties, identifying and quantifying them is not easy. It requires very
advanced instruments, expensive reagents and expertise. Hence, the number of
reports on this matter is very limited.
First
authentic report on the phenolic compounds present in areca nut was published by Govindarajan &
Mathew (1963). They were working in Central Food Technology Research Institute
(CFTRI) Mysore, and they tried to identify prominent phenolic compounds present
in Chali (White supari). They had identified Catechin, Epicatechin and Leucocyanidins,
using a very rudimentary “Paper chromatography method”. In 2013, Chavan &
Singhal from “Institute of Chemical Technology” Mumbai, confirmed the presence
of catechin and epicatechin in Chali (White supari) using advanced Liquid
Chromatography- Mass spectroscopy (LC-MS) method.
In China, Zhang
et al. (2014) had used most advanced High Performance Liquid Chromatography -
Mass Spectroscopy (HPLC-MS) to identify some of the prominent phenolic
compounds present in the areca nuts of 5 month's maturity. They had collected the areca
nut sample from Hainan Province of China. They have reported the presence of Epicatechin
and Syringic acid in the areca nuts of 5 month's maturity.
One more
recent report on the prominent phenolic compounds present in areca nut came
from Indonesia. Sari et al., (2020) had tried to identify and quantify the
prominent phenolic compounds present in unripe (green) areca nuts (6-7 months’
maturity) collected from West Kalimantan & West Papua and ripened areca
nuts (perhaps 9-10 months’ maturity), collected from Banda Aceh & North
Sumatra, Indonesia. They had used an advanced LC-MS analysis to quantify those
phenolic compounds. They have reported the presence of Catechin &
Epicatechin in all the four areca nut samples. In areca nut sample collected
from West Papua (6-7 months’ maturity), Sinapic acid, quercetin and resveratrol
were also reported. However, they were absent in the ripened areca nut samples.
Their results are presented below.
Song et al. (2022) have identified and quantified the prominent phenolic compounds present in the areca seed (after dehusking ) of the areca nuts of 5 month's maturity. They had chosen the areca nut samples from Hainan Province of China. They had used a most advanced UHPLC–MS/MS to identify and quantify the phenolic compounds. They too have reported the presence of large amount of Catechin and Epicatechin, which is in concurrence with the results of Zhang et al. (2014). Furthermore, they have reported the presence of a significant amount of Procyanidins, which was not reported by Zhang et al. (2014). Some major compounds reported by them are listed below.
Our recent
study of unripe green areca nut (6-7 months’ maturity) collected from Belur,
Sagar Taluk, Shivamogga district using a most advanced UHPLC-MS/MS confirmed
the presence of large number of flavonoids. This study was conducted in 2022 in our lab at NITK Surathkal, Karnataka, India. Altogether 61 compounds belong to
phenolic acids, flavonoids, proanthocyanidins, alkaloids, lignans, xanthones,
Sesquiterpenes classes were identified. Arecatannin B1, Catechin, Propelargonidin,
Procyanidin B2, 5,3'-Dihydroxy-6,7,4'-trimethoxyflavanone, Coniferyl alcohol
and Nubigenol were the prominent compounds found in areca nut of 6-7 month's maturity. Isorhamnetin,
Phloretin, Isoferulic acid, Hydroxybenzoic acids and syringic acid commonly
found in Chinese and Indonesian areca nuts were also identified.
References
1. Govindarajan & Mathew (1963). Polyphenolic
substances of arecanut-I. Chromatographic analysis of fresh mature nut. Phytochemistry.
Vol. 2. pp. 321t o 326
2. Chavan & Singhal (2013). Separation of polyphenols
and arecoline from areca nut (Areca catechu L.) by solvent extraction, its
antioxidant activity, and identification of polyphenols. Journal of Science of Food & Agriculture. Vol. 93(10), pp. 2580–2589.
3. Zhang et al. (2014). Optimization of extraction
conditions of areca seed polyphenols and evaluation of their antioxidant
activities. Molecules. Vol. 19(10), pp. 16416–27
4. Sari et al., (2020). Distinct phenolic, alkaloid and
antioxidant profile in betel quids from four regions of Indonesia, Scientific
Reports, Vol. 10:16254
5. Song et al., (2022). UHPLC-MS/MS identification,
quantification of flavonoid compounds from Areca catechu L. extracts and in
vitro evaluation of antioxidant and key enzyme inhibition properties involved
in hyperglycemia and hypertension. Industrial Crops & Products. Vol. 189,
pp. 115787.
***
