INTRODUCTION:

Sulawesi Island is a habitat for around 48 species of Etlingera, 7 of which are endemic to Southeast Sulawesi¹. Pharmacological studies have also been conducted on several species, such as Etlingera punicea², Etlingera paviena³, Etlingera fulgens², Etlingera elatior^4,5,6, Etlingera calophrys^7,8, Etlingera brevilabrum⁹ and Etlingera alba^10,11. Etlingera alba is an endemic plant of Southeast Sulawesi¹². Prior studies have shown that it has pharmacological activity, particularly antibacterial activity against Salmonella enterica and Escherichia coli, anti-inflammatory agent that reduces the level of swelling in the palm of rats^10,13, and an antioxidant that reduces 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals^11,14,15.

According to a study, free radicals are considered a major factor in aging, cancer, diabetes, skin tissue injury and hardening of the arteries^13,16. To neutralize these free radicals, antioxidant compounds have a function to prevent adverse effects of processes or reactions that cause excessive oxidation of the body's biological systems. Natural exogenous sources of antioxidants such as phenolics, flavonoids, carotenoids and vitamins are phytochemical compounds derived from plants¹⁷.

Previous studies reported that Etlingera contains phytochemical compounds such as phenolics^18,19, flavonoids^20,21,22, steroids^5,7,18, terpenoids¹⁹, alkaloids¹¹ and diarylheptanoids^23,24. Diarylheptanoid compounds have been shown to have activity as antioxidants^16,25,26. However, no systematic investigation has been reported on antioxidant components of Etlingera, especially E. alba to date.

To further explore antioxidants from E. alba stems, here we describe the isolation and characterization of three diarylheptanoids: yakuchinone A (1), 7-(4″-hydroxy-3″-methoxyphenyl)-1-phenyl-hept-4-en-3-one (2), and oxyphylacynol (3) (Figure 1). The three diarylheptanoids were first reported from the stem of E. alba. The molecular structures of secondary metabolites were explained based on spectroscopic techniques by comparing the data with the results reported in the literature. The antioxidant activity of all isolated compounds was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) test.

Figure 1. Chemical structures of compounds 1-3

MATERIALS AND METHODS:

Plant Material:

Etlingera alba stems were obtained from Punggaluku Village, Laeya District, South Konawe, Southeast Sulawesi (4°19ʼ26”S 122°28ʼ58”E, 325m). The species was determined at the Biological Research Center of the National Research and Innovation Agency (No. 1535/IPH.1.01/If.07/VIII/2019). E. alba usually grows in forests, areas on the edges of steep cliffs or under bamboo thickets, at an altitude of 66-960 meters above sea level. This plant is 3.6-5.3m tall with 13-27 leaves. The distance between leaf buds can reach 18-20cm. The diameter at the base of leaf buds is 5.5-7.5cm, the color is golden brown, and it has a velvet texture. The leaf sheaths are green with brown spots. The plant has lanceolate leaves, with a size of about 52-90 × 8-17.5 cm. This plant is glabrous, and the edges of the leaves are hairy and golden brown. The leaves are wavy or wrinkled, their pointed base are elongated, and the tip is tapered. Leaf stalks are 0.7-2.5cm long with a bare surface. The rhizome of E. alba is 2-5cm in diameter, dark orange-brown and covered with fine hairs at the base, and there are no stilt roots. Flowers are 4.2-5.6cm long. The petals are 2.1–2.9cm long, reaching 11–12 mm below the stamen heads, and are 10–22mm shorter than the corolla lobes. The color of the petals is creamy green with a hint of red at the tips, with 3 gaps of 0.2–0.5cm and fine hairs that are tightly adherent and scattered and most prominent on the lower parts. They also have 3 serrated tips. The corolla tube is 21-34mm long. It is white with fine hairs attached and scattered in the tube along the stamen tube. The fruit has a size of 8-15x 7-12cm and is oval or sometimes an ellipsoid. The length of the fruit stalk is 15-19cm with 33-42 fruits. The peduncle has a length of 7.2-10cm, while the spicules are 7-8.2 × 7.5-9cm. The color of the fruit is orange-red with a length of 2.0 × 1.7cm with 7-12 spines. The calyx is 1.9-2.0cm with a long stalk (pedicel) of 0.9cm¹.

Figure 2. Etlingera alba stems were obtained from Punggaluku Village, Laeya District, South Konawe, Southeast Sulawesi (4°19ʼ26”S 122°28ʼ58”E, 325 m).

Figure 3. Etlingera alba A.D. Poulsen

Sample Preparation:

Sample preparation was carried out by first collecting the stems of E. alba and then sorting them from other plant materials/parts. Next, they were washed, wet sorted, chopped, dried and dry sorted. The sample was dried in the sun and covered with a black cloth for 5-7 days. Once it had been dry, the sample was then crushed with an electric chopper to produce simplicia in the form of elongated fine fibers. Then, it was stored in a clean, dry container and protected from light.

Isolation of Secondary Metabolite Compounds:

The isolation encompassed several stages: maceration extraction, fractionation, and purification. One kg of simplicia was macerated with methanol until the simplicia was completely submerged in the solvent. The maceration was carried out for 3 × 24hours. It was repeated until a clear filtrate was obtained. The results of the maceration were then separated from the simplicia dregs using Whatman filter paper and then evaporated using a vacuum rotary evaporator (Buchi Rotavapor R-210 Germany) at a temperature of 40-45°C with a speed of 65-90rpm to obtain a thick extract of 33grams. The viscous extract was then fractionated with vacuum liquid chromatography (VLC) using a 10cm column, silica gel stationary phase (250g), and a mixture of n-hexane:ethyl acetate (8:2, 5:5, 2:8) and methanol 100% which produced 4 fractions: A (0.56g), B (1.98g), C (4.72g), and D (32.7g). Fraction B was then purified using a preparative centrifuge (Chromatotron model 7924T) on a stationary phase of silica gel PF254 containing gypsum and a mobile phase of n-hexane:ethylacetate (8:2) to produce 272mg of yakuchinone A (1) and 42mg of 7-(4″-hydroxy-3″- methoxyphenyl)-1-phenyl-hept-4-en-3-one (2). Further purification of fraction C using preparative centrifuges on the stationary phase of silica gel PF254 containing gypsum and the mobile phase of n-hexane:chloroform:methanol (7:2:1) produced 41 mg of oxiphylacinol (3).

Molecular Structure Determination:

To determine the structure of isolated compounds, spectroscopic techniques were used. Liquid chromatography-tandem mass spectroscopy (LC-MS/MS) analysis used Xevo G2-XS QTOF (Waters Corporation, Milford, USA) to determine the mass. Spectrums were measured using a fourier transform infra-red (FT-IR) (Alpha II-Bruker, Billerica, MA, USA) spectrometer. Proton nuclear magnetic resonance (¹H NMR) and carbon-13 nuclear magnetic resonance (¹³C NMR) spectra were determined using FT NMR spectrometer (JEOL JNM-ECZ500R/S1, Japan) at 500.159 MHz (¹H) and 125.765 MHz (¹³C).

Yakuchinone A (1) was obtained as yellow liquid. Its molecular formula is C₂₀H₂₄O₃. LC-MS/MS (m/z) 313.18 [M+H]⁺, 179.07, 161.11, 151.09 and 133.11. FT-IR spectrum in KBr ν_max (cm^-1) 3410 (O-H), 3031(C-H alkenes), 2925, 2902 (C-H alkanes), 1705 (C=O), 1600, 1490 (C=C aromatic), 1440 (C-C alkanes), 1249 (C-O aryl ethers) dan 1087 (C-O alcohol). ¹H NMR (CDCl₃, 500.159 MHz) and ¹³C NMR (CDCl₃, 125.765 MHz) in Table 1.

7-(4″-hydroxy-3″- methoxyphenyl)-1-phenyl-hept-4-en-3-one (2) was also obtained as yellow liquid. Its molecular formula is C₂₀H₂₂O₃. LC-MS/MS (m/z) 311.16 [M+H]⁺, 205.09, 177.09, 133.07 and 105.07. FT-IR spectrum in KBr ν_max (cm^-1) 3396 (O-H), 3028(C-H alkenes), 2921, 2911 (C-H alkanes), 1702 (C=O), 1625, 1554, 1499 (C=C aromatic), 1442 (C-C alkanes), 1251 (C-O aryl ether) dan 1091 (C-O alcohol). ¹H NMR (CDCl₃, 500.159 MHz) and ¹³C NMR (CDCl₃, 125.765 MHz) in Table 1.

Oxiphylacinol (3) was obtained as yellow liquid. Its molecular formula is C₂₀H₂₆O₃. LC-MS/MS (m/z) 315.20 [M+H]⁺, 181.09, 163.11, 151.08 and 133.10. FT-IR spectrum in KBr ν_max (cm^-1) 3385 (O-H), 2933, 2857 (C-H alkanes), 1602, 1515 (C=C aromatic), 1453 (C-C alkanes), 1271 (C-O aryl ether) dan 1034 (C-O alcohol). ¹H NMR (CDCl₃, 500.159 MHz) and ¹³C NMR (CDCl₃, 125.765 MHz) in Table 1.

Table 1. ¹³C and ¹H NMR data of compounds 1-3

S.No	δ_C (ppm)			δ_H(ppm) (ΣH, m, J (Hz))
S.No	1	2	3	1	2	3
1	29.6	29.9	31.7	2.81 (2H, t, 7.5)	2.83 (2H, m)	2.71; 2.57 (2H, m)
2	44.7	42.2	39.6	2.67 (2H, t, 7.5)	2.81 (2H, m)	1.73 (2H, m)
3	210.4	199.8	71.5	-	-	3.62 (1H, m)
4	43.0	130.8	37.6	2.38 (2H, t, 7.0)	6.10 (1H, d, 16.0)	1.49 (2H, m)
5	23.5	146.4	25.5	1.59 (2H, m)	6.83 (1H, dt, 7.0 and 16.0)	1.51; 1.33 (2H, m)
6	31.1	34.2	31.9	1.59 (2H, m)	2.53 (2H, t, 8)	1.63; 1.48 (2H, m)
7	35.8	34.5	36.1	2.59 (2H, t, 7.0)	2.76 (2H, t, 8)	2.61 (2H, m)
1'	133.1	142.3	134.2	-	-	-
2'	111.2	128.4	111.2	6.67 (1H, d, 1.5)	7.16 (2H, m)	6.70 (1H, s)
3'	146.5	128.6	146.6	-	7.28 (2H, m)	-
4'	144.0	126.3	143.9	-	7.19 (1H, m)	-
5'	114.4	128.6	114.5	6.81 (1H, d, 8.0)	7.28 (2H, m)	6.83 (1H, d, 8.0)
6'	120.8	128.4	121.1	6.64 (1H, dd, 2.0 and 8.0)	7.16 (2H, m)	6.68 (1H, d, 2.5)
3'-OCH₃	56.0	-	56.1	3.84 (3H, s)	-	3.87 (3H, s)
1"	142.3	133.2	142.7	-	-	-
2"	128.4	111.2	128.6	7.14 (1H, m)	6.69 (1H, d, 2.0)	7.18 (1H, m)
3"	128.5	146.4	128.5	7.26 (1H, m)	-	7.27 (1H, m)
4"	125.8	144.0	125.9	7.17 (1H, m)	-	7.18 (1H, m)
5"	128.5	114.4	128.5	7.26 (1H, m)	6.81 (1H, d, 8.0)	7.27 (1H, m)
6"	128.4	120.9	128.6	7.14 (1H, m)	6.66 (1H, dd, 2.0 and 8.0)	7.18 (1H, m)
3"-OCH₃	-	56.0	-		3.85 (3H, s)	-

Antioxidant Activity by DPPH Radical-Scavenging Assay:

The radical inhibition properties were determined based on previously reported methods^27,28 by microdilution method²⁹. Samples were diluted at various concentrations (200.0, 100.0, 50.0, 25.0, 12.5, 6.25, 3.12 and 1.56µg/mL) in DMSO solvent. One tenth mM DPPH radical solution (HIMEDIA) was prepared in 100 mL DMSO. As much as 200μL of sample solution was put into a 96 well micro plate and then 200μL of DPPH solution was added. The mixture of the two solutions was incubated at room temperature in the dark for 30 minutes. Absorbance was determined using a UV Vis spectrophotometer (Genesys 150 UV Vis, Thermo Scientific, USA) at 517nm. The obtained value was then calculated against the absorbance of the blank which was the absorbance of the sample (200μL) and dimethyl sulfoxide (DMSO) solvent (200μL). DPPH solution (200μL) in DMSO solvent (200μL) was the control in this test. DPPH inhibitory activity was calculated based on the equation:

Inhibitory activity (%) = (ADC-ATS)/ADC x 100%

where ADC is the absorbance of the DPPH control and ATS is the absorbance of the test sample in radicals.

Test samples showing antioxidant activity with % inhibition above 50% were then determined for IC₅₀ values using Graphpad Prism 5 (Graphpad Software®, La Jolla, Canada, USA). The positive control used in this test is ascorbic acid.

RESULT AND DISCUSSION:

Compound 1 was obtained as yellow oil. This isolate, based on the identification of the FT-IR spectrum, showed absorption at ν_max 3410 cm^-1 for the hydroxyl group (OH), 3031 cm^-1 for the C-H alkene group, 2925 and 2902 cm^-1 for the C-H group of alkanes, 1705 cm^-1 for the carbonyl group (C=O), 1600 and 1490 cm^-1 for aromatic carbon groups, 1440 cm^-1 for C-C alkane groups, and ν_max 1249 and 1087 cm^-1 for C-O ether and alcohol groups. Interpretation of ¹³C NMR data with DEPT technique showed 18 carbon signals representing 20 carbon atoms including one methyl carbon (CH₃: δC 56.0ppm), six methylene carbons (CH₂: δC 44.7, 43.0, 35.8, 31.1, 29.6 and 23.5ppm), eight carbon metin (CH: δC 128.5 (two symmetric carbons), 128.4 (two symmetric carbons), 125.8, 120.8, 114.4 and 111.3ppm) and five quarter carbon (cq: δC 210.4, 146.5, 144.0, 142.3 and 133.1ppm). The carbonyl ketone is shown at the quaternary carbon δC 210.4, while the methyl with a large chemical shift indicates that the methyl binds to the oxygen atom to form methyl oxide. Protons at chemical shifts above 5ppm (δH 7.26, 7.17, 7.14, 6.81, 6.67 and 6.64ppm) are deshielded by the anisotropic effect of the alkene groups identified in the ¹³CNMR signal (CH: δC 128.5, 128.4, 125.8,120.8, 114.4 and 111.3ppm). The proton signal with a singlet multiplicity (s) at the chemical shift δH 3.84ppm consisting of three protons indicates a methyl proton that is deshielded by the presence of an atom with a large electronegativity (oxygen). This oxygen-bonded methyl forms a methoxy group attached to the quaternary carbon. Four proton signals with triplet (t) and multiplet multiplicity respectively at chemical shift δH 1.52 –2.81ppm (J = 7.0 – 8.0 Hz) indicate that these protons are close to each other and there are other protons around their chemical environment. Based on these data and the comparison of their spectral data with those in the literature^8,30,31, compound 1 is determinate as yakuchinone A.

Compound 2 was obtained as yellow oil. The identification of the FT-IR spectrum showed absorption at ν_max 3396 cm^-1 for the hydroxyl group (OH), 3028 cm^-1 for the C-H alkene group, 2921 and 2911 cm^-1 for the C-H alkane group, 1702 cm^-1 for the carbonyl group (C=O), 1625.1554 and 1499 cm^-1 for the aromatic carbon group, 1442 cm^-1 for the C-C alkane group, and 1251 and 1091 cm^-1 for the C-O ether and alcohol groups. ¹³C NMR data showed the presence of one carbon methyl oxide (CH₃: δC 56.0 ppm), four methylene carbons (CH₂: δC 42.2, 34.5, 34.2 and 29.9 ppm), ten carbon methine (CH: δC 146.4, 130.8, 128.6 (2 symmetric carbons), 128.4 (2 symmetric carbons), 126.3, 120.9, 114.4 and 111.2 ppm) and five quaternary carbons (Cq: δC 199.8, 146.4, 144.0, 142.3 and 133.2 ppm). The carbonyl group of a ketone is shown at the quaternary carbon δC 199.9 ppm. Proton on sliding chemistry δH 7.28, 7.19, 7.16, 6.83, 6.81, 6.69, 6.66 and 6.10 ppm derived from alkene groups which were identified at δC 146.4, 130.8, 128.6, 128.4, 126.3, 120.9, 114.4 and 111. A proton signal at 2 ppm at chemical shift δH 3.85 ppm with singlet multiplicity (s) indicates methyl oxide protons. With regards to these data and the comparison of their spectral data with those in the literature^8,32, compound 2 is determinate as 7-(4″-hydroxy-3″-methoxyphenyl)- 1-phenyl-hept-4-en-3-one.

Figure 4. ¹³C NMR spectroscopy of compounds 1-3 (Joel, 125 MHz)

Compound 3 was obtained as yellow oil. Identification of the FT-IR spectrum showed absorption at ν_max 3385 cm^-1 for the hydroxyl group (OH), 2933 and 2857 cm^-1 for the C-H alkane group, 1602 and 1515 cm^-1 for the aromatic carbon group, 1453 cm^-1 for the C-C alkane group and 1271 and 1034 cm^-1 for the C-O ether and C-O alcohol groups. ¹³C NMR data showed the presence of one carbon methyl oxide (CH₃: δC 56.1 ppm), six methylene carbon (CH₂: δC 39.6, 37.6, 36.1, 31.9, 31.7 and 25.5 ppm), nine carbon methine (CH: δC 128.6, 128.6, 128.5, 128.5, 125.9, 121.1, 114.5, 111.2 and 71.5 ppm) and four quaternary carbons (Cq: δC 146.6, 143.9, 142.7 and 134.2 ppm). The hydroxyl group is shown on the methine carbon δCH 71.5 ppm. Protons at chemical shifts δH 7.27, 7.18, 6.82, 6.70 and 6.68 ppm are protons from the alkene group identified at δC 128.6, 128.6, 128.5, 128.5, 125.9, 121.1, 114.5 and 111.2 ppm. Proton signal at chemical shift δH 3.87 ppm with singlet multiplicity (s) indicates methyl oxide protons. Based on these data and the comparison of their spectral data with those in the literature³³, compound 3 is determinate as oxiphylacinol.

Diarylheptanoids are a group of secondary metabolites with two aromatic rings connected by seven linear carbon chains in their molecular structure. This group of compounds is known to exist only in a few species of plants in a limited family, especially in Zingiberaceae, including E. alba species. Etlingera alba is endemic to Southeast Sulawesi and the same species has never been found in other areas¹². However, several diarylheptanoids have also been recognized from other species such as E. elatior and E. calophrys with different structures³⁴. The difference in structural diversity lies in the substituents in the aromatic ring and heptane chain, as well as the number of double bonds in the heptane chain. The diversity of structures due to differences in substituents will certainly form different pharmacological properties.

The pharmacological properties as antioxidants of the three compounds were tested using the DPPH method, and the results are shown in Figure 6. Compound 1 showed very strong antioxidant activity in neutralizing free radicals with IC₅₀ values of less than 50µg/mL, while compounds 2 and 3 showed strong activity in neutralizing free radicals with IC₅₀ values in the range of >50–100µg/mL^35,36,37. Considering the structural approach, this activity was most likely caused by the presence of hydroxyl substituents in the aromatic ring. Compounds that have one or several hydroxyl groups can inhibit oxidation and reduce free radical compounds that can damage cells. Antioxidants function as reducing agents. They are easily oxidized by free radicals because they have double bonds. In the presence of OH groups attached to these double bonds, free radicals will capture hydrogen atoms and cause the formation of oxygen radicals which will then be delocalized through resonance, resulting in stable radicals³⁸. These pharmacological properties indicate that the isolated compounds are most likely to be good lead compounds of the antioxidant agents in this plant.

Figure 5. ¹H NMR spectroscopy of compounds 1-3 (Joel, 500 MHz)

Figure 6. Antioxidant activity of compounds 1-3

CONCLUSION:

The results can be concluded that the compounds yakuchinone A, 7-(4″-hydroxy-3″-methoxyphenyl)-1-phenyl-hept-4-en-3-one and oxyphylacynol are diarylheptanoids compounds from E. alba stems that provide antioxidant effects with a very strong ability to reduce free radicals.

CONFLICT OF INTEREST:

None declared.

ACKNOWLEDGMENTS:

The authors acknowledge the Directorate of Research Halu Oleo University for supporting this research trough scheme Penelitian Dasar Internal 2023 with contract number 029.b/UN29.18/KU/2023 awarded to Dr. Wahyuni.

REFERENCES:

1. Droop, J. Book review - Etlingera of Sulawesi. 2013. In: Poulsen, A.D. (Ed.), Edinburgh Journal of Botany, vol. 70. Nat Hist Pub (Borneo), Malaysia. 2012. DOI:10.1017/S096042861300019X£52.

2. Nagappan, T., Tatin, Y., and Skornickova, J. L. Investigation on bioactive potential of selected Wild Ginger, Genus Etlingera from Tasik Kenyir, Terengganu. Greater Kenyir Landscapes: Social Development and Environmental Sustainability: From Ridge to Reef. 2018; 75–82. https://doi.org/10.1007/978-3-319-92264-5_7

3. Tachai S, Nuntawong N. Uncommon secondary metabolites from Etlingera pavieana rhizomes. Nat Prod Res. 2016 Oct;30(19):2215-9. doi: 10.1080/14786419.2016.1146884. Epub 2016 Feb 22. PMID: 26901239.

4. Chan, Eric W.C., Lim, Y. Y., and Wong, S. K. Phytochemistry and pharmacological properties of Etlingera elatior: A review. Pharmacognosy Journal. 2011; 3(22), 6–10. https://doi.org/10.5530/pj.2011.22.2

5. Wahyuni, Grashella, S.H.L., Fitriah, W.O.I., Malaka M.H., Fristiohady A., Imran, and Sahidin, I. Antibacterial and antioxidant potentials of methanol extract and secondary metabolites from Wualae rhizome (Etlingera elatior). Current Research Bioscience and Biotechnology. 2019; 1(1), 13-16.

6. Fristiohady, A., Sadrun, B., Wahyuni, Yusuf, M.I., Malik, F., Purnama L.O.M.J., Bafadal, M., Leorita, M., Jabbar, A., and Sahidin, I. 2020. Hepatoprotective activity etlingera elatior (Jack) R.M. Smith extract against CCl4-induced hepatic toxicity in male wistar rats, Research Journal of Pharmacy and Technology. 2020; 13(10): 4585-4590.

7. Sahidin, I., Wahyuni, Malaka, M. H., Jabbar, A., Imran, and Manggau, M. A. Evaluation of antiradical scavenger activity of extract and compounds from Etlingera calophrys stems. Asian Journal of Pharmaceutical and Clinical Research. 2018; 11(2): 238–241. https://doi.org/10.22159/ajpcr.2018.v11i2.22535

8. Sahidin, I., Wahyuni, Rahim, A.R., Arba, M., Yodha, A.W.M., Rahmatika, N.S., Sabandar, C.W., Manggau, A.M., Khalid, R.M., Almuqarobbun, L.O.M.R., Rosandy, A.R., Chahyadi, A., Hartati, R., and Elfahmi. Radical scavenger and antimicrobe of diarylheptanoids and steroids from etlingera calophrysrhizome. Sustainable Chemistry and Pharmacy. 2022; 29: 100767.

9. Mahdavi, B. Chemical constituents of the aerial parts of Etlingera brevilabrum (Zingiberaceae). Der Pharma Chemica. 2014; 6(2): 360–365.

10. Hamsidi, R. Wahyuni, W., Sahidin, I., Apriyani, A., Harsono, H., Azizah, N. A., Malik, F., Yodha, A. W. M., Purnama, L. O. M. J., and Fristiohady, A. Suppression of proinflammatory cytokines by etlingera alba (A.D.) Poulsen rhizome extract and its antibacterial properties. Advances in Pharmacological and Pharmaceutical Sciences. 2021; 1-6

11. Wahyuni, Diantini, A., Ghozali, M., Subarnas, A., Julaeha, E., Amalia, R., and Sahidin, I. Phytochemical screening, toxicity activity and antioxidant capacity of ethanolic extract of etlingera alba rhizome. Pakistan Journal of Biological Sciences. 2021; 24(7): 807–814.

12. Wahyuni, Ajeng Diantini, Mohammad Ghozali, Anas Subarnas, Euis Julaeha, Riezki Amalia, Adryan Fristiohady, Andini Sundowo, Sofa Fajriah, Yuni Elsa Hadisaputri, Raden Maya Febrianti, Fauzia Azzahra, Agung W.M. Yodha, I. Sahidin.. In-Vitro Anticancer Activity Of Chemical Constituents From Etlingera Alba Poulsen Against Triple Negative Breast Cancer And In Silico Approaches Towards Matrix Metalloproteinase-1 Inhibition. Indonesian Journal of Science and Technology. 2022; 7(2): 2528-1410. https://doi.org/10.17509/ijost.v7i2.50547

13. S. Shanthi, M. Sahina Begum, M.Senthuja. In- vitro Antioxidant and Anti-aging activity of a Traditional Ayurvedic Formulation. Research Journal of Pharmacy and Technology. 2023; 16(8): 3521-4. doi: 10.52711/0974-360X.2023.00581

14. Pradeep Kumar Samal. Investigation of Antioxidant activity of Butea monosperm barks. Research J. Pharm. and Tech 6(6): June 2013; 610-613.

15. Gulzar Ahmed Rather, Anima Nanda, Ezekiel Raj, N. Mathivanan, K. Thiruvengadam, Mohmmad Ashaq Sofi, B. K. Nayak. Determination of Phytochemicals, in vitro Antioxidant and Antibacterial activity of Lavandula angustifolia Mill. Research Journal of Pharmacy and Technology. 2023; 16(3): 1161-6.

16. Ritu Paliwal, Veena Sharma, Pracheta, Sadhna Sharma. Elucidation of Free Radical Scavenging and Antioxidant Activity of Aqueous and Hydro-Ethanolic Extracts of Moringa oleifera Pods. Research J. Pharm. and Tech. 2011; 4(4): 566-571.

17. Jabbar A, Wahyuono S, Puspitasari I, Sahidin I. Free radical scavenging activity of methanol extract and compounds isolated from stems of Etlingera rubroloba A.D Poulsen. International Journal Of Pharmaceutical Research. 2021; 13(1): 1099-1105. doi:org/10.31838/ijpr/2021.13.01.478

18. Jabbar A, Hamzah H, Nandini E, et al. The Effectiveness of Begonia Multangula Blume Leaf Ethanol Extract as Polymicrobial Antibiofilm on Catheters. Egyptian Journal of Chemistry. 2022; 65(13). doi:10.21608/ejchem.2022.118622.5341

19. Y MI, Diantini A, Ghozali M, Sahidin I, Fristiohady A. Immunomodulatory Potency Etlingera rubroloba A.D. Poulsen Fruit Ethanol extract against Macrophage Phagocytic Activity and CD4 Levels in Wistar Male Rats. Research Journal of Pharmacy and Technology. 2022; 15(9): 4067-4072. doi:10.52711/0974-360X.2022.00682

20. Jabbar A, Wahyuono S, Puspitasari I, Sahidin I. Xanthine Oxidase Inhibitory Activity and DPPH radical scavenging Assay of isolated compound from Etlingera rubroloba (Blume) A.D Poulsen stem. International Journal of Pharmaceutical Research. 2021; 13(1): 1994-2002. doi:https://doi.org/10.3188/ijpr/2021.13.01.316

21. Jabbar A, Sahidin I, Monstavevi S, Malaka M, Malik F, Ilyas MY. Antioxidant and Anti-Inflammatory Activity of Ethanol Extract Stem of Etlingera rubroloba A.D. Poulsen. Pakistan Journal of Biological Sciences. 2022; 25(10): 885-891. doi:10.3923/pjbs.2022.885.891

22. Somanjana Khatua, Snigdha Paul, Krishnendu Acharya. Mushroom as the Potential Source of New Generation of Antioxidant: A Review. Research J. Pharm. and Tech. 2013; 6(5): May 496-505

23. Jabbar A, Hamzah H, Nandini E, et al. The Effectiveness of Begonia Multangula Blume Leaf Ethanol Extract as Polymicrobial Antibiofilm on Catheters. Egyptian Journal of Chemistry. 2022; 65(13). doi:10.21608/ejchem.2022.118622.5341

24. BP Muley, SS Khadabadi, NB Banarase, HA Sawarkar. The Antioxidant Activity of the Leaves and Petals of Calendula officinalis Linn. Research J. Pharm. and Tech. 2009; 2(1): 173-175.

25. Tiwari VK, Mishra BB. Opportunity, Challenge and Scope of Natural Products in Medicinal Chemistry. Research Signpost; 2011.

26. Wahyuni W, Yusuf MI, Malik F, Lubis AF, Indalifiany A, Sahidin I. Immunomodulatory Effects of Ethanol Extract of Melophlus sarasinorum Sponge Against Phagocytosis Activity of Macrophage Cells on Balb/C Male Mice. Galenika Journal of Pharmacy. 2019; 5(2): 147-157. doi:10.22487/j24428744.2019.v5.i2.13611

27. Chetan S. Sonawane, Sushama D. Patil, Deepali M. Jagdale, Leena Patil, Vilasrao J. Kadam. In Vitro Antioxidant Activity of Methanolic Extract of Leaves of Ornamental Plant Epipremnum aureum Linn. Research J. Pharm. and Tech. 2011; 4(8): 1237-1239.

28. Sandip Sutariya, Vidhi Pansuriya, Malika Sharma, AB Bajpai, Amit Gupta. Antimicrobial, Antioxidant and Anti-inflammatory potential of flavonoid and terpenoid from Gymnosporia montana. Research Journal of Pharmacy and Technology. 2023; 16(4):1945-0.

29. Solichah AI, Anwar K, Rohman A, Fakhrudin N. Phytochemical Profile and Antioxidant Activity of Some Artocarpus Genus Plants in Indonesia. Journal of Food and Pharmaceutical Sciences. Published online July 26, 2021:443-460. doi:10.22146/jfps.2026

30. Ning An, Hong-wu Zhang, Li-zhen Xu, Shi-lin Yang, dan Zhong-mei Zou. New diarylheptanoids from the rhizome of Alpinia officinarum Hance. Food Chemistry. 2010; 119 (2).

31. Gulzar Ahmed Rather, Anima Nanda, Ezekiel Raj, N. Mathivanan, K. Thiruvengadam, Mohmmad Ashaq Sofi, B. K. Nayak. Determination of Phytochemicals, in vitro Antioxidant and Antibacterial activity of Lavandula angustifolia Mill. Research Journal of Pharmacy and Technology. 2023; 16(3):1161-6.

32. Han, J., T., Sang Y., L., Youn H., L., Nam-In B, Antioxidative diarylheptanoids from the fruits of Alpinia oxyphylla, Food Science and Biotechnology. 2007; 16 (6).

33. Lin, R. J., Yen, C. M., Chou, T. H., Chiang, F. Y., Wang, G. H., Tseng, Y. P., Wang, L., Huang, T. W., Wang, H. C., Chan, L. P., Ding, H. Y., and Liang, C. H. Antioxidant, anti-adipocyte differentiation, antitumor activity and anthelmintic activities against Anisakis simplex and Hymenolepis nana of yakuchinone A from Alpinia oxyphylla. BMC Complementary and Alternative Medicine. 2013; 13. https://doi.org/10.1186/1472-6882-13-237

34. Wahyuni, Ajeng Diantini, Mohammad Ghozali, Sahidin. Etlingera Genus: Phytochemical Screening And Anticancer Activity. Jurnal Farmasi Sains dan Praktis. 2021; 7(3): 343-355

35. Yodha, A.W.M., Badia, E., Musdalipah, M., Setiawan, M. A., Daud, N. S., Fusvita, A., Fristiohady, A., and Sahidin, I. Essential Oils of Alpinia monopleura and Their Antibacterial and Antioxidant Activity. Molekul. 2023; 18(1): 80–88. https://doi.org/10.20884/1.jm.2023.18.1.6265

36. Imran, Wahyuni, Adryan Fristiohady, Mesi Leorita, M. Hajrul Malaka, Muhammad Ilyas Y, Musadar, Nur Syifa Rahmatika, Ahmad Darmawan, Sofa Fajriah, Agung W. Mahatva Yodha, Sahidin I. Radical Scavenger and Anti-diabetic Potencies of Etlingera elatior Fruits growing in South East Sulawesi-Indonesia. Research Journal of Pharmacy and Technology. 2022; 15(5): 2141-6. doi: 10.52711/0974-360X.2022.00355

37. Sandip Sutariya, Vidhi Pansuriya, Malika Sharma, AB Bajpai, Amit Gupta. Antimicrobial, Antioxidant and Anti-inflammatory potential of flavonoid and terpenoid from Gymnosporia montana. Research Journal of Pharmacy and Technology. 2023; 16(4): 1945-0.

38. Sumit Phulera, Neelam Gurung, Kavita Maria Arora, Gaurav Kumar, Loganathan Karthik, Kokati Venkata Bhaskara Rao. Evaluation of Phytochemical Composition, Antioxidant and Cytotoxic Activity of Ipomoea fistulosa Leaves (Convolvulaceae). Research J. Pharm. and Tech. 2014; 7(4): 454-459.

Received on 26.09.2023 Modified on 18.03.2024

Research J. Pharm. and Tech 2024; 17(9):4394-4400.

DOI: 10.52711/0974-360X.2024.00679