Infrared spectroscopy study of the ethanolic leaf extracts of Artocarpus heterophyllus and Litchi chinensis

doi:10.15406/mojabb.2017.01.00029

MOJ

eISSN: 2576-4519

Applied Bionics and Biomechanics

Research Article Volume 1 Issue 5

Infrared spectroscopy study of the ethanolic leaf extracts of Artocarpus heterophyllus and Litchi chinensis

Saifuddin AHM,¹

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Ruhul Mahbub MD,¹ Sharmin Akter Mst,¹ Jannatul Fardous²

¹Department of Pharmacy, Jahangirnagar University, Bangladesh
²Department of Pharmacy, Commilla University, Bangladesh

Correspondence: AHM Saifuddin, Department of Pharmacy, Jahangirnagar University, Savar, Dhaka- 1342, Bangladesh

Received: January 12, 2017 | Published: December 13, 2017

Citation: Saifuddin AHM, Mahbub RMD, Akter SM, et al. Infrared spectroscopy study of the ethanolic leaf extracts of Artocarpus heterophyllus and Litchi chinensis. MOJ App Bio Biomech. 2017;1(5):189–190. DOI: 10.15406/mojabb.2017.01.00029

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Abstract

A phytochemical study has been conducted using infrared spectroscopy to distinguish different chemical moieties present in leaves of Artocarpus heterophyllus (Jack fruit) and Litchi chinensis (Litchi). Both of these trees are widely known in the world and have various pharmacological activities. However, both leaf extracts were analyzed using FTIR and interpreted from the obtained spectrum. Both leaves are supposed to have –OH, -NH₂ groups as they give a wide peak in higher region wavelength (3400-3200cm¹). Meta-substituted aromatic ring and imides may be present in litchi leaf extract as peaks were found in 850-700cm^-1 and near 1700cm^-1 respectively, but not in jackfruit leaf. While phenol group is present in the spectrum of jackfruit leaf extract only. Asymmetric methyl group is present in both leaf extract as gives absorption in the 2957-2851cm^-1 region.

Keywords: phytochemical study, leaf extracts, ftir, spectrum, asymmetric methyl group

Abbreviations

FT, fourier transform; IR, infrared; FTIR, fourier transforms infrared

Introduction

Infrared spectroscopy is a standard method of analytical pharmacy and chemistry which provides the images of vibration of atoms of compound Dole et al.¹ Fourier transform (FT) infrared (IR) spectrometers were commercially introduced in 1970. They were characterized by peculiar analytical performances that mainly consisted in the use of trace sample (down to 100ng), high throughput measurements without sample destruction and with minimal sample preparation Bellisola et al.² Artocarpus heterophyllus (Jack-fruit), belonging to family ‘Moraceae’ Taylor et al.³ It is known as ‘Kathal’ in Bangladesh and found in most of the part in Bangladesh. The young fruits are acrid, astringent, carminative and tonic. The ripe fruits are sweet, cooling, laxative, an aphrodisiac and tonic. The bark is useful in fever, boils, wounds, skin diseases. The jackfruit is considered an invasive species in Brazil, especially in the Tijuca Forest National Park in Rio de Janeiro Lakheda et al.⁴

Litchi chinensis (Litchi) is a tropical and subtropical fruit native to South East Asian countries and now widely cultivated throughout the world Duan et al.⁵ Litchi or lychee, a fruit with a rough brown pericarp surrounding a white flesh (aril), is popular for its delicious taste and possible health benefits Jiang et al.⁶ Various biologically active constituents are present in different parts of lychee (leaves, flower, fruit, pericarp and seed). These compounds are reported to exhibit several pharmacological activities Taak et al.⁷

Materials and method

Collection of plant material

The jackfruit and litchi leaves were collected from Jahangirnagar University campus, Bangladesh. The leaves were dried and crushed manually with the wooden arrangement and made in powder form.

Extraction

The plant materials were sun-dried first and then, dried in an oven at reduced temperature (<700C) to make suitable for grinding. The powdered plant materials were submerged in sufficient volume of ethanol in an air-tight flat-bottomed container for seven days, with occasional shaking and stirring. The extracts were then filtered and dried in an electrical water bath. Fourier transforms infrared (FTIR) spectroscopy: Fourier transform infrared (FTIR) spectra were recorded using FTIR spectrophotometer (IR prestige- 21, Shimadzu). The samples (JFL_Extract and Lit_Extract) were previously ground and mixed thoroughly with potassium bromide (an infrared transparent matrix) in a ratio of 1:100. The KBr discs were prepared by compressing the powders at a pressure of 6 tons for 5min in a hydraulic press (Shimadzu, Japan). Twenty-five scans for Artocarpus heterophyllus and thirty-eight scans for Litchi chinensis were obtained at a resolution of 1cm^-1, from 4000 to 500cm^-1.

Results and discussion

The spectrum (Figure 1) obtained from FTIR. It is found that absorption vibration took place in the whole infrared region (4000cm^-1 to 667cm^-1). Most of the absorption peaks are found in the frequency of 1700 cm^-1 to 1000 cm^-1 for both of the extracts. This indicates the presence of nitro compounds, esters, ethers, primary, secondary and tertiary alcohols generally Sharma et al.⁸ From the JFL_Extract spectrum, the appearance of the medium band in 3500 -3300 cm^-1 regions, we can assume the presence of –OH,-NH₂ group. Besides this band on 3301 cm^-1 indicates the existence of alkyne stretches (≡C-H) with strong intensity Pavia et al.⁹ Combination and overtone absorption occurs in the 2957-2851cm^-1 region. This absorption may be due to C-H stretching from methyl or methylene groups. Absorption is asymmetric as absorption took place in higher wavelength Sharma et al.⁸ Absorption peaks in the fingerprint region (the region below 1500cm^-1) here indicates the presence of some different functional groups viz. alcohols, esters, lactones, anhydrides Pavia et al.⁹ Absorption in this region particularly 1350^-1000cm^-1 takes place due to C-O stretching. Peaks in this region also recommend existence of phenol group here as phenols absorb near 1200cm^-1 Sharma et al.⁸ and such peaks are present in the spectrum (1166cm^-1 and 1224cm^-1).

Figure 1 FTIR spectrograms of, (A): Jack fruit leaves (JFL_Extract); (B): Litchi leaves extract (Lit_Extract).

Spectrum for Lit_Extract is quite similar to the previous one. Presence of –OH, -NH2 group is possible here also as a wide peak is present in 3404 cm^-1 region with medium intensity. An interesting finding in this spectrum is that combination and overtone absorption occurs in a 2851-2958 cm^-1 region which is same as the jackfruit leaf extract. So methyl or methylene groups are present here as the result of C-H stretching. Numbers of absorption peaks are higher in fingerprint region, and absorption took place in 1500-667 cm^-1 wavelength. Absorption below 1000cm^-1 indicates the presence of aromatic ring and also is very useful for identifying the type of substitution in the aromatic ring Sharma et al.⁸ In this spectrum absorption peaks in 668.3cm^-1, 720.4cm^-1 and 830.3cm^-1 are found, and we can assume that meta-substituted benzene ring is present. Because absorption in 850-710cm^-1 and 750-700cm^-1 recognizes meta-substituted compounds and mono-substitution of benzene ring respectively. Esters, aldehydes, ketones, imides may be present in litchi leaf due to absorption in 1900^-1650 cm^-1 region as a result of C=O stretching. Presence of imides is possible, as several two strong bands (doublet) found near 1700cm^-1 wavelength Sharma et al.⁸

Conclusion

From the above discussion and spectrum analysis, it is clear that different functional groups are present in both jack-fruit and litchi leaf. Presence of phenol groups in jackfruit leaf extract emphasizes its antioxidant properties and its use for different therapeutic purposes, e.g., fever, wound healing, skin diseases. Moreover, the substituted aromatic ring structure is present in litchi leaf while absent in jack-fruit leaf as per spectrum analysis. Further study on both of these leaf constituents may help to discover a new molecule for medicinal use.