9. Alkaloids present in Areca nut - Part IV

 

In the last couple of Blogs, the arecoline & other alkaloid contents in the green immature areca nut studied in different countries was discussed. In this Blog, arecoline & other alkaloid content of the areca fruits of 9-10 month’s maturity is discussed.

Shivashankar et al., (1968) from CFTRI Mysore, had studied the chemical composition of Chali (White supari) purchased from important areca growing regions of Kerala and Karnataka over two years (1964 to 1966). They had used rudimentary methods available at that time to estimate arecoline content. They concluded that the arecoline content varies between 0.1 to 0.7 % in Chali on dry weight basis, collected from different areca growing regions of Karnataka and Kerala state of India. 

Wang et al., (1997), had studied the arecoline content of areca nuts of 9-10 months’ maturity collected from Taiwan. They had reported the arecoline content of 0.16% in the ripened fruit on fresh weight basis. Jantarat et al., (2013) had reported an arecoline content of 0.094 % in 8 months old, matured nuts on fresh weight basis. They had collected the areca nut sample from Nakhon Si Thammarat, Thailand.

Chavan and Singhal (2013) had analyzed the arecoline content of Chali purchased from the local market in Mumbai using HPLC method. They had reported an arecoline content of 1.279% (12.79 mg/g).  Jain et al., (2017), have done a comprehensive study of arecoline content in Chali and various areca nut products sold in the market in China and India. They had reported an arecoline content of 0.064 to 0.222 % (dry weight) using advance LC-MS/MS method. Arecoline content of 0.119% was the median value and 0.127% was the mean value in the Chali (white supari) collected from the bulk traded in the Mumbai market. The arecoline content found in the Gutka samples produced and sold in India were 0.074 & 0.116 %. The arecoline content in the Bing lang purchased from Hunan province China were in the range of 0.107 to 0.144%.  Levels of Guvacine ranged from 0.139 to 0.816% dry weight, accounting for more than 50% of the total alkaloid content in most of the products. The levels of Arecaidine and Guvacoline ranged from 0.014 % to 0.170 % and 0.017 % to 0.099 % dry weight, respectively.

In conclusion, about a dozen alkaloids have been identified so far in areca nuts and Arecoline is considered as a key biologically active alkaloid among them. Its concentration will be high in the early developmental stage and decreases with maturity. Areca nut cultivated in Taiwan, China, Indonesia and Darwin Island, Australia, reported arecoline content on higher side (0.3% and above) in the unripe green nuts. Whereas the unripe green areca nuts studied in Thailand and India had lower arecoline content (less than 0.3%). Lot of variation (up to 400%) in arecoline concentration was found in areca nuts cultivated in different regions.  The analysis of various areca nut samples sold in the market revealed that the arecoline content in them is in the range of 0.064 to 0.222 % (0.64 to 2.22 mg/g). In one instance, the arecoline content was found to be as high as 1.279% (12.79 mg/g) in Chali sample collected from Mumbai market, India.

References:

Shivashankar et al., (1968). Physical and chemical characteristics of processed areca nuts. Journal of Food Science & Technology, Vol.  6, pp. 113-116.

Wang et al., (1997), Contents of Phenolics and Alkaloids in Areca catechu Linn. During Maturation, Journal of Agriculture & Food Chemistry. Vol. 45, pp. 1185-1188

Jantarat et al., (2013), A Simple and Rapid HPLC Technique for Determination of Arecoline in Areca Nut (Areca catechu L.) Extract, Walailak Journal of Science & Technology, Vol. 10(1), pp. 57-66.

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.

Jain et al (2017). Analysis of Alkaloids in Areca Nut-Containing Products by Liquid Chromatography−Tandem Mass Spectrometry. Journal of Agricultural and Food Chemistry, Vol. 65, pp. 1977−1983

8. Alkaloids present in Areca nut - Part III

In the last two Blogs, the arecoline content of green areca nuts of 6-7 months maturity has been discussed. In the current Blog, Arecoline and other alkaloids content of green nuts of 2-5 months maturity is being discussed. Areca nuts of this maturity is being utilized for consumption in Taiwan and China.
Wang et al., (1997), had studied the arecoline content of fresh areca nuts of 2 and 3 months’ maturity collected from Taiwan. They had reported the concentration of all the alkaloids in 2-3 months’ maturity as follows.

 

Yuan et al., (2012) had studied the arecoline content of fresh areca nuts collected from twelve prominent areca growing districts of Hainan province of China and had analyzed those fresh nuts (perhaps 4-5 months’ maturity). They had also estimated the concentration of Arecaidine and Guvacine in them as follows.

Jantarat et al., (2013) had reported an arecoline content of 0.143 % in 3 months old fresh nuts.  They had purchased the areca nuts from Nakhon Si Thammarat, Thailand and had used HPLC to estimate the alkaloids. 

From the above cited reports, it is clear that the arecoline content in the green nuts of Taiwan (2-3 month's maturity) was in the range of 0.7 % (7 mg/g), whereas the arecoline content was mere 0.143% (1.43 mg/g) in the areca nut from Thailand. A significant variation was found in the arecoline content in the green nuts collected from Hainan China as well. The values were ranging between 0.217 to 0.764 % (2.17 to 7.64 mg/g)

References:

1.    Wang et al., (1997), Contents of Phenolics and Alkaloids in Areca catechu Linn. during Maturation, Journal of Agriculture & Food Chemistry. Vol. 45, pp. 1185-1188

2.     Yuan et al. (2012), Alkaloids from Areca (Betel) Nuts and Their Effects on Human Sperm Motility In Vitro. Journal of Food Science , Vol. 77 (4), pp. T70-78.

3.     Jantarat et al., (2013), A Simple and Rapid HPLC Technique for Determination of Arecoline in Areca Nut (Areca catechu L.) Extract, Walailak Journal of Science & Technology, Vol. 10(1), pp. 57-66.

                                                                                  ***

7. Alkaloids present in Areca nut - Part II

 

A study was undertaken by our team in NITK Surathkal in 2021 and 2022 to study the arecoline content in the unripe areca nuts of 6-7 months’ maturity. The areca nut samples were collected from various locations as explained in my Blog 4. Phenolic compounds present in Areca nut (Karnataka, India): Part – II (under the label Chemical constituents of Areca nut). The arecoline content of the fresh areca nut samples was determined immediately after the collection. Very sensitive HPLC method was employed to find the arecoline content in the samples. The results are presented below.

The median arecoline content among the 21 samples was 2.17 mg/g on Fresh weight (FW) basis. Sample from K. Hosur, Tarikere Taluk, Chickmagalur District had the highest arecoline content of 3.66 mg/g (0.366 %) on fresh weight basis. Whereas the sample from Gajanur, Shivamogga district had the lowest arecoline content of  0.71 mg/g (0.071%) on fresh weight basis.

In general, the arecoline content of all the samples analyzed in this study was on the lower side compared to the reports published elsewhere. Only three samples had the arecoline content more than 0.3 % out of 21 samples analyzed. In general, if areca nut is having 0.3% arecoline content (3.0 mg/g) is dried as it is, the dried nut would contain 0.75 % (7.5 mg/g) arecoline on dry weight basis. Interestingly, two samples had arecoline content less than 0.1%, which is a remarkable discovery.                                                                                                                                                                                                      

             ***

6. Alkaloids present in Areca nut - Part I

 

Arecoline, arecaidine, guvacine, and guvacoline are the most important and prominent alkaloids found in areca nut. Nicotine, dichroine, acatechu A, acatechu B, homoarecoline, N-ethyl-1,2,5,6-tetrahydro-1-methyl-3-pyridine carboxamide and arecatemines are some of the minor alkaloids found in some areca nuts. Arecoline is found to be the most important alkaloid among all, due to its role in modulating many physiological functions upon human consumption.

In humans, depending on the dose and individual responsivity, arecoline produces cognition-enhancing, psychostimulant, euphoric, pro-arousal, aphrodisiac, anxiolysis and sedative effects. In other words, arecoline produces enhanced alertness and learnability, enhances the mood, gives a feeling of great pleasure, causes awakening, stimulates the sexual desire, reduces anxiety and promote calmness. Arecoline has a wide spectrum of pharmacological effects beyond Central Nervous System modulating cardiovascular, digestive and endocrine systems as well.  Like nicotine, arecoline also evokes addiction and withdrawal symptoms (upon discontinuation). Withdrawal symptoms could be mood swings, anxiety, irritability and insomnia.

Arecoline content in Green Areca nuts (6-7 month's maturity)

Many research groups have studied the arecoline content in areca nuts cultivated in various geographical locations and at various level of maturity. Mathew et al., (1964) from CFTRI Mysore, had studied the arecoline content of areca nuts of 6-7 months maturity collected from Kyatsandra, Mysore, Thirthahalli and Vittal in Karnataka state and Pudupady in Kerala state of India.  They have concluded that the arecoline content was in the range of 0.14 to 0.19 %.

Huang and Mcleish (1989) had reported an arecoline content of 0.3-0.63 % in fresh areca nuts (perhaps 6-7 months’ maturity) collected from Darwin, Australia using HPLC method. This was the first report of use of HPLC for estimating arecoline. They had estimated the arecaidine (0.31-0.66%), guvacoline (0.03-0.06%) and guvacine (0.19 0.72%) in those samples as well.

Sari et al., (2020) had studied the arecoline content of unripe green areca nuts (6-7 months’ maturity) collected from two different regions of Indonesia. They had reported an arecoline content of 0.44 & 0.69 % (on dry weight basis).

References:

1.  Mathew et al. (1964) Studies on Arecanut: Part I - Changes in Chemical Composition & Physical Characteristics of Nuts with MaturityIndian Journal of Technology, Vol. 2, No.3, pp. 90-96

2.    Huang and McLeish (1989). High-performance liquid chromatographic determination of the alkaloids in betel nut, Journal of Chromatography, 415, pp. 447-450.

3.   Sari et al., (2020). Distinct phenolic, alkaloid and antioxidant profile in betel quids from four regions of Indonesia, Scientific Reports, Vol. 10:16254

                                                                              ***

5. Phenolic compounds present in Areca nut: Part – III

 

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.

                                                                          ***

4. Phenolic compounds present in Areca nut (Karnataka, India): Part – II

A comprehensive study on the Total Phenolic Compounds” Present in the unripe (Green) areca nuts of 6-7 month’s maturity was carried out in my lab by my team in NITK Surathkal. Generally, the harvesting season for green nuts starts in September and continues up to December for making Red Supari (Kempadike) in Karnataka State. The fresh nuts of 6-7 months’ maturity harvested by the farmers for making “Red Supari” (kempadike) were collected from various districts of Karnataka in Dec 2021 & Nov 2022. The locations were chosen so that most of the prominent, traditional Red Supari producing Taluks were covered in this study. The goal was to study the effect of geographical locations on the chemical constituents of the areca nut. The sample locations are pictorial represented below.

The total phenolic content of the fresh areca nut samples was determined immediately brought to the lab under frozen state and the chemical constituents were determined the next day.

The data is presented below.

Lot of variations in the phenolic content was noticed among the samples. The areca nuts cultivated in the relatively dry regions of Shivamogga, Davanagere, Chickmagalur and Haveri districts had higher phenolics compared to other regions.

                                                                        *** 

3. Phenolic compounds present in Areca nut : Part - I

 

Areca nut contains a large number of phenolic compounds in substantial quantity. Flavonoids (flavones, flavanones, flavanols, flavonols), phenolic acids and polyphenols (procyanidins, areca tannins etc.) are some of the important classes of phenolic compounds found in areca nuts. These compounds are responsible for the dark brownish color in the boiled nuts (Red supari). They impart astringent taste, and they turn red in the presence of lime. Most of the perceived therapeutic properties of areca nut are attributed to these flavonoids, phenolic acids and polyphenols. Almost all of them are highly potent antioxidants. A brief account of proven health benefits of some of the prominent phenolic compounds present in areca nut shall be posted in subsequent Blogs.

Very few reports are available on the systematic study of total phenolic compounds present in the areca nuts at its developmental stages. A brief account of those reports is presented below.

Thailand

Total phenolic content of areca nuts cultivated in Nakhon-Pathom province of Thailand was estimated by Wetwitayaklung et al., (2006).  They have used a standard method to extract and analyze the phenolic content of areca nuts of maturity 1 month to 8 months. They have reported that the total phenolics is in the range of 8 mg/g (by weight on dry basis) in the 1-month-old nut, reaches 10.5 mg/g at the 4th month and reaches 7 mg/g in the 8th month areca nut. The results of their study are presented below. 

Indonesia

One more recent study on the estimation of chemical constituents of areca nuts was reported from Indonesia. Sari et al., (2020) had studied the total phenolic content of unripe (green) areca nuts (6-7 months’ maturity) collected from West Kalimantan and West Papua and ripened areca nuts (perhaps 9-10 months’ maturity), collected from Banda Aceh & North Sumatra, Indonesia. The phenolic content was in the range of 10.88 mg/g to 21.67 mg/g on dry weight basis. The unripe (green) nut collected from West Papua province of Indonesia had the highest phenolic content 21.67mg/g on dry basis, whereas the unripe (green) nuts from West Kalimantan had only 10.8 mg/g of Phenolic compounds. The mature areca fruits from North Sumatra & Banda Aceh had phenolic content of 11.1 mg/g & 12.2 mg/g respectively.

China

A recent study on the total phenolic present in the areca nuts of 5 months maturity has been reported by Song et al., (2022). They had chosen the areca nut samples from Hainan Province of China and they analysed the phenolic content of the seed after separating the husk. They reported the total phenolic content of 36.3 mg/g on dry weight basis. In another study, Wang et al., (2023) had analysed the total phenolic content of areca nut (with husk) of 5 months maturity, collected from 11 prominent areca growing regions of Hainan Province of China. They had used High Performance Liquid Chromatography (HPLC) method to determine the phenolic content. They have reported an average value of 36 mg/g (on dry weight basis). As they had estimated the Phenolic content of areca nut along with the husk, the values seem to be highly inflated.

From the aforesaid literatures, it is clear that there is a great variability in their concentrations in areca nuts cultivated in different regions of the world. The values varied from 6.98 mg/g (8-month sample from Thailand) to 36.3 mg/g (5-month sample from China). The unripe (green) areca nuts of 4 to 5 months maturity have the highest concentration of Phenolic compounds. Interestingly, the areca nut of 4-5 months maturity is harvested and processed to make flavoured Bing lang in China (Refer my Blog No. 6 & 7 under the label “Global areca nut production”).   

References:

1.     1.  Wetwitayaklung et al., (2006). The study of antioxidant capacity in various parts of Areca catechu L. Naresuan University Journal, Vol. 14 (1), pp. 1-14.

2.    2. Sari et al., (2020). Distinct phenolic, alkaloid and antioxidant profile in betel quids from four regions of Indonesia, Scientific Reports, Vol. 10:16254

3.    3. 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.

4.   4.Wang et al., (2023). Evaluation of Areca Quality Based on Principal Component and Hierarchical Cluster Analyses in Hainan, China. HORTSCIENCE, Vol. 58(6), pp. 699–703.

***

2. Major constituents of Areca nut (Supari)

The major constituents of the areca nut are carbohydrates, lipids, proteins, crude fiber, phenolic compounds (flavonoids, phenolic acids and polyphenols), alkaloids and mineral matter. Jayalakshmi & Mathew (1982) have reported that the unripe areca nut of 6-7 months’ maturity will generally have a moisture content in the range of 69.4–74.1% (by weight) whereas the ripe fruit will have moisture content in the range of 38.9–56.7 %. The moisture content will vary depending upon the variety, agroclimatic conditions and the agriculture practices.

The major chemical of unripe green (6-7 months’ maturity) and ripe areca nuts are given below on dry weight basis except for moisture (Adapted from Jayalakshmi & Mathew (1982)). Rudimentary analytical techniques and instruments available at that time were utilized to estimate the components. Nevertheless, the following Table gives the rough estimation of major components. 

As per the report of Mathew et al., (1964) from CFTRI Mysore, who had studied the composition of areca nuts harvested at 2 months, 4-5 months, 6-7 months and 9 months’ maturity collected from Kyatsandra, Mysore, Thirthahalli and Vittal in Karnataka state and Pudupady in Kerala, the lipid (oil) content of the areca nut increased from a low, 1-4 %, in the tender stages to a high, 10-15 %, in the ripe stage. Similarly, the polysaccharide (starch and cellulose) content also starts with a low value at the tender stage and increases progressively until at ripe stage. Crude fibre (cellulose and hemicellulose) starts with a very low value (1-2 %) and with maturity and ripening fibre will be formed continuously and the rate of formation increases until the ripe areca nut showed a value of about 15 %. Rapid protein accumulation happens till the fruits are 3 months old and thereafter the value remained more or less constant. Phenolic substances start with a high value in the early stage and progressively decrease during the developmental stage and reaches the lowest value in the fully ripened fruit. The considerable increase in the hardness of the nut coincides with drop in moisture content and build-up of polysaccharides and crude fibre. Lignification (formation of lignin) and high degree of polyphenol polymerization occur in matured fruit, contributing to the larger insoluble residue and increased hardness of the nut. While the trend in changes of physical and chemical properties with maturity for the samples from different regions was the same, individual variations in relative proportion of constituents were significant.

The study by Jayalakshmi & Mathew (1982) and Mathew et al. (1964) clearly demonstrates that the protein content, lipid content and crude fiber content will be highest in the mature fruit (9-10 months maturity) which is used for making Chali (White supari) and Niradike (Doma, fermented Areca nut). Water content in the areca nut keeps decreasing during the developmental stage and reaches the minimum value in the matured fruit compared to its early stages.

Other major constituents such as Phenolic compounds and alkaloids shall be discussed in my subsequent Blogs.

Reference:

1.      Jayalakshmi A, Mathew AG (1982) Chemical composition and processing. In: Bavappa KVA, Nair MK, Kumar TP (eds) The areca nut palm. Central Plantation Corps Research Institute, Kerala, pp 225–244.

2.      Mathew A.G, Venkataramu S.D, Govindarajan V.S (1964). Studies on Arecanut: Part I - Changes in Chemical Composition & Physical Characteristics of Nuts with Maturity. Indian Journal of Technology, Vol. 2, No.3, pp. 90-96.

***

1. Chemical constituents of Areca nut

A handful of research papers are available on the composition of areca nut. However, only a couple of papers can be considered for all the practical purposes as they used standard protocols and sophisticated instruments ensuring reproducibility and sensitivity. 

Review of processing practices of areca nut in various major areca growing regions of the world shows that areca nut is harvested at four different stages of maturity.

1.      Unripe areca nut of 2-3 months maturity (In Taiwan and consumed fresh with husk)

2.      Unripe areca nuts of 4-5 months maturity (In China, sliced and smoke dried)

3.      Unripe areca nuts of 6-7 months maturity (In India, Indonesia, boiled and sundried)

4.      Ripe areca fruits of 9-10 months maturity (In India, Bangladesh, Bhutan, Malysia, Thailand, Indonesia etc. sundried or fermented.)

Areca nut is processed in four different ways, after harvesting, as follows.

1.      Unripe areca nuts of 4-5 months maturity: Sliced and smoke dried. Steeped in sugar, mint syrup to impart flavour and dried. Marketed as Bing lang in sachets in China.

2.       Unripe areca nuts of 6-7 months maturity: Boiled in Chogaru/Kali repeatedly and sundried, sold as Red Supari (Kempadike) in India and Indonesia.

3.      Ripe areca fruits of 9-10 months maturity: Dehusked and sun dried, sold as White Supari (Chali) in India, Bangladesh, Bhutan, Malysia, Thailand, Indonesia etc.

4.      Ripe areca fruits of 9-10 months maturity: Fermented under the earth or in water tanks, sold as Niradike or Doma in India (assam, Meghalaya) & Bhutan.

Considering the fact that areca nut is harvested at different stages of maturity and processed by different methods, chemical composition of the final product is bound to change substantially. Hence it is not possible to state a one general composition of areca nut, which is applicable to all the varieties. Furthermore, the agroclimatic conditions also known to influence the composition of the areca nut to a great extent, especially with respect to some of the important active principles. Areca nut of India is found to possess different chemical composition in comparison to areca nut of Indonesia and elsewhere. Unfortunately, the reports on all these varieties are not available. However, I am going to make an effort to present the composition of areca nut in my subsequent posts under the label "Chemical constituents of areca nut". 

***