Metabolite Profiling of Aquilaria malaccensis Leaf Extract Using Liquid Chromatography-Q-TOF-Mass Spectrometry and Investigation of Its Potential Antilipoxygenase Activity In-Vitro

Abstract

The Aquilaria malaccensis species of the genus Aquilaria is an abundant source of agarwood resin and many bioactive phytochemicals. Recent data regarding the chemical constituents and biological activities of Aquilaria leaves led us to attempt to qualitatively profile the metabolites of Aquilaria malaccensis leaves from a healthy, noninoculated tree through phytochemical screening, GC-MS, and LC/Q-TOF-MS. The present work is also the first to report the antilipoxygenase activity of A. malaccensis leaves from healthy noninoculated tree and investigate its toxicity on oral mucosal cells. A total of 53 compounds were tentatively identified in the extract, some of which have been described in literature as exhibiting anti-inflammatory activity. A number of compounds were identified for the first time in the extract of A. malaccensis leaf, including quercetin, quercetin-O-hexoside, kaempferol-O-dirhamnoside, isorhamnetin-O-hexoside, syringetin-O-hexoside, myricetin, tetrahydroxyflavanone, hesperetin, sissotrin, and lupeol. The antilipoxygenase assay was used to determine the lipoxygenase (LOX) inhibitory potential of the extract, while a WST-1 assay was conducted to investigate the effect of the extract on oral epithelial cells (OEC). The extract implied moderate anti-LOX activity with IC50 value of 71.6 µg/mL. Meanwhile, the cell viability of OEC ranged between 92.55% (10 µg/mL)–76.06% ± (100 µg/mL) upon treatment, indicating some potential toxicity risks. The results attained encourage future studies of the isolation of bioactive compounds from Aquilaria malaccensis leaves, as well as further investigation on the anti-inflammatory mechanisms and toxicity associated with their use.

Aquilaria malaccensis Lam. Thymelaeaceae

“…It should be noted that many publications have published the species under the synonym Aquilaria agallocha. Major secondary metabolites reported include alkaloids, benzophenones, coumarins, fatty acids, flavonoids, steroids, saponins, tannins, terpenoids, tocopherols, and xanthones (Batubara et al 2018;Chen et al 2012;Eissa et al 2020;Nik Wil et al 2014;Said et al 2016).…”

“…Eissa et al (2018) also carried out an identification of the leaf extracts which shows the presence of many other compounds including 1-nitro-9,10-dioxo-9,10dihydro-anthracene-2-carboxylic acid diethylamide, 1-pyrazolidinethiocarboxanilide, 4-ethyl-3-propyl-, 1,1,1,3,5,5,5-heptamethyltrisiloxane, 1,2-dihexylcyclopropene, 1,2,5oxadiazol-3-amine,4-(3-methoxyphenoxy), 1,4-bis(trimethylsilyl)benzene, 1,4-eicosadie ne, 1,6:3,4-dianhydro-2-deoxy-β-d-lyxo-hexopyranose, 1,6,10-dodecatrien-3-ol,3,7,11trimethyl-,(E)-, 1H-cycloprop[e]azulene, decahydro-1,1,7-trimethyl-4-methylene-, 2(4H)-benzofuranone,5,6,7,7a-tetrahydro-4,4,7a-trimethyl-, 2-hexadecene,3,7,11,15-te tramethyl-,[R-[R*,R*-(E)]], 2-propanol,1-chloro-,phosphate (3:1), 3-nonene, 4,8,12,16-Tetramethylheptadecan-4-olide, 4(1H)-pteridinone, 2-amino-6-methyl-, 5-methyl-1,3diazaadamantan-6-one, 5-methyl-2-pyrazinylmethanol, 8-dodecenol, 9-borabicyclo [3.3.1]nonane, 9-[3-(dimethylamino)propyl]-, 10-methyl-E-11-tridece-1-ol acetate, 13-te tradecen-1-ol acetate, 17-octadecynoic acid, methyl ester, D-erythro-pentose,2-deoxy-, cyclohexan-1,4,5-triol-3-one-1-carboxylic acid, α,α,4-trimethylbenzyl carbanilate, α-D-Mannopyranoside, methyl 3,6-anhydro-, acetic acid, behenic alcohol, bicyclo[3.1.1]he ptane,2,6,6-trimethyl-,[1R-(1α,2β,5α)]-, bicyclo[10.8.0]eicosane, cis-butanoic acid,3oxo-, propyl ester, carane,4,5-epoxy-,trans, cyclodecanol, decane,1-fluoro-, ditetradecyl ether, eicosane,9-octyl-, ethanone,2-(2-benzothiazolylthio)-1-(3,5-dimethylpyrazolyl)-, fumaric acid,2-chloropropyl tridecyl ester, fumaric acid,2-decyl tridecyl ester, hexane dioic acid, bis(2-ethylhexyl) ester, hexadecanoic acid, methyl ester, cis-9-hexadecenoic acid, isoheptadecanol, methyl N-(thioformyl)dithiocarbamate, octanal, phthalic acid,8chlorooctyl isobutyl ester, phthalic acid, butyl cycloheptyl ester, phthalic acid, dodecyl e thyl ester, phthalic acid, butyl hexyl ester, phytol, piperidine, 3,5-dimethyl-, silicic acid, diethyl bis(trimethylsilyl) ester, sulfurous acid,2-propyl undecyl ester, tetraacetyl-d-xylonic nitrile, tetradecanal, (5-Isopropyl-2-methylphenoxy)trimethylsilane, (3,7,7-trimethylbicyclo[2.2.1]hept-2-yl)-methanol, and [1,2,4]-triazolo[4,3-a][1,3,5]-triazine,5,7-diace tylamino-3-methyl-. The study on the anti-inflammatory activity of the leaf extracts was carried out again (Eissa et al 2020) in which many other compounds have been found using GCMS and LC/Q-TOF-MS. The GCMS analysis yielded many detected che mical compounds including 1-ethynyl-1-cyclohexanol, 1,1,3,3-tetramethyl-1,3-disiletane , 1,2-dipentylcyclopropene, 3,4-dihydroxy-3,4-dimethylhexane-2,5-dione, 3,4,5,6,7-pe ntahydroxy-1-phenoxyheptan-2-one, 4-cyclopropylmethylbenzonitrile, 4-ethyldecane, 5-methyl-2-(1-methylethylidene)cyclohexan-1-one oxime, 9-octadecenoic acid, 1H-imidazole-4-acrylamide, 2R,3S-9-[1,3,4-Trihydroxy-2-butoxymethyl]guanine, N-butylace tamide, N-hydroxycarbamic acid,2-(isopropoxycarbonylamino)ethyl ester, ethyl hexade canoate, methyl hexadecanoate, methyl N-amino-N-methylcarbamodithioate, pinane, and trimethylurea.…”

“…According to Eissa et al (2018), the best anti-inflammatory activity is noticed in Soxhlet extracts, indicated by an inhibition value larger than 50%. According to Eissa et al (2020), the anti-inflammatory property is due to the inhibition of lipoxygenase enzymes known as anti-LOX. Other activities: The leaf extracts also have antidiabetic properties (Hashim et al 2016;Pranakhon et al (2011).…”

A Review: Aquilaria Species as Potential of Pharmacological

“…Aquilaria is a tree native to the rainforests of Southeast Asia and belongs to the Thymelaeaceae family [4], of which the genus Aquilaria spp. this includes 47 species, and 22 of them are included in the plant list.…”

“…this includes 47 species, and 22 of them are included in the plant list. Some of the known species including Aquilaria malaccensis, Aquilaria subintegra, Aquilaria crassna, and Aquilaria sinensis [4] are used for therapeutic purposes as a traditional medical treatment of gout, headache, arthritis, cough, vomiting, asthma, leprosy and anorexia [10]. The aquilaria tree is known to produce a fragrant agarwood resin and is used in perfumes.…”