Aquilaria Species Research Articles

Statistical analysis for chemical compound based on several species of aquilaria essential oil

The paper examines the characterization of Aquilaria essential oils from different species, namely Aquilaria malaccensis, Aquilaria beccariana, Aquilaria crassna, and Aquilaria subintegra, renowned for agarwood production in Malaysia. Gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID) were employed for extracting essential oil data, facilitating compound identification. Subsequently, a preliminary analysis focused on classifying significant chemical compounds in the samples. The study then utilized boxplot pre-processing for visualizing and interpreting data distribution. The statistical analyses were performed using MATLAB software version R2021b, considering two key parameters which are the peak area (%) of significant chemical compounds and the classification of Aquilaria species (A. beccariana, A. malaccensis, A. crassna, and A. subintegra) based on their chemical composition. The results, presented through boxplot analyses, demonstrated a clear representation of the parameters and their distribution in the data. This method not only confirmed the potential of boxplot analysis in statistical evaluation of significant compounds in Aquilaria essential oil but also suggested its applicability for further classification work.

Enhancing Aquilaria Species Classification using Agarwood Oil Analysis and K-Nearest Neighbors (KNN) as Machine Learning

Enhancing Aquilaria Species Classification using Agarwood Oil Analysis and K-Nearest Neighbors (KNN) as Machine Learning

An Updated Review of Aquilaria Species: Distribution, Chemical Constituents and Authentication Methods

An Updated Review of Aquilaria Species: Distribution, Chemical Constituents and Authentication Methods

Laxative Properties of Agarwood Leaves of Aquilaria Species: A Review

Agarwood leaves have long been used as herbal medicine due to their diverse pharmacological qualities, oneof which being laxative abilities to relieve constipation. Constipation is interpreted as a gastrointestinal ailment in which the stools are dry and firm with difficulty and infrequentevacuation. People generally suffer in silence and choose to take over-the-counter medications rather than addressing the problem. The main issue here is that currently available laxatives induce undesirable sideeffects such as cramps, diarrhea, nausea, and others. Previously conducted research discovered that Aquilariaspecies agarwood leaf extract has laxative qualities and has no adverse side effects on animal testing. Genkwanin 5-O-β primeveroside and mangiferin are shown as the major bioactive compounds in agarwood leaves extract that induce laxative effects. This review focuses on the laxative characteristics of agarwood leaves, bioactive compounds, and previous studies on in vivotesting.

Genome-wide analysis of respiratory burst oxidase homolog (Rboh) genes in Aquilaria species and insight into ROS-mediated metabolites biosynthesis and resin deposition.

Respiratory burst oxidase homolog (Rboh) generates reactive oxygen species (ROS) as a defense response during biotic and abiotic stress. In Aquilaria plants, wounding and fungal infection result in biosynthesis and deposition of secondary metabolites as defense responses, which later form constituents of fragrant resinous agarwood. During injury and fungal invasion, Aquilaria tree generates ROS species via the Rboh enzymes. Despite the implication of Rboh genes in agarwood formation, no comprehensive genomic-level study of the Rboh gene family in Aquilaria is present. A systematic illustration of their role during stress and involvement in initiating signal cascades for agarwood metabolite biosynthesis is missing. In this study, 14 Rboh genes were retrieved from genomes of two Aquilaria species, A. agallocha and A. sinensis, and were classified into five groups. The promoter regions of the genes had abundant of stress-responsive elements. Protein-protein network and in silico expression analysis suggested their functional association with MAPK proteins and transcription factors such as WRKY and MYC2. The study further explored the expression profiles of Rboh genes and found them to be differentially regulated in stress-induced callus and stem tissue, suggesting their involvement in ROS generation during stress in Aquilaria. Overall, the study provides in-depth insight into two Rboh genes, AaRbohC and AaRbohA, highlighting their role in defense against fungal and abiotic stress, and likely during initiation of agarwood formation through modulation of genes involved in secondary metabolites biosynthesis. The findings presented here offer valuable information about Rboh family members, which can be leveraged for further investigations into ROS-mediated regulation of agarwood formation in Aquilaria species.

Pre-processing technique of Aquilaria species from Malaysia for four different qualities

The paper interprets data distribution by using boxplot pre-processing in classify the quality of Agarwood oil for eleven chemical substances into four different qualities. The varieties usage of Agarwood oil makes it considered as an expensive and valuable product on the essential oil market. Perfumes, fragrances, incense, aromatherapy, and traditional medicine are the most popular Agarwood oil applications. However, the classification of Agarwood oil grades does not yet have standard grading method. This because it has been graded manually into different qualities by using human sensory evaluation. Boxplot analysis involving eleven chemical subtances that will be focusing in this study by concerned the quality for low, medium low, medium high and high. ɤ-eudesmol, ar-curcumene, β-dihydro agarofuran, ϒ-cadinene, α-agarofuran, allo aromadendrene epoxide, valerianol, α-guaiene, 10-epi-ɤ-eudesmol, β-agarofuran, and dihydrocollumellarin compounds are the selected significant compounds that represent the input for boxplot. Agarwood oil consist 660 data samples from low, medium low, medium high, and high quality. The result in this study showed that the four selected significant compounds (ɤ-eudesmol, 10-epi-ɤ-eudesmol, β-agarofuran, and dihydrocollumellarin) are important as a marker for Agarwood oil quality classification. The identification of chemical substances on high quality done as reference for future research studies.

Aquilaria sinensis: An Upstart Resource for Cucurbitacin Production Offers Insights into the Origin of Plant Bitter (Bi) Gene Clusters.

Cucurbitacins, oxygenated tetracyclic triterpenoids that are found mainly in the Cucurbitaceae family, play essential roles as defensive compounds, serving as allomones against herbivores and pathogens and as signals for insect-parasite recognition. These compounds also exhibit various pharmacological effects. The biosynthesis of cucurbitacins is largely regulated by the bitter (Bi) gene, encoding an oxidosqualene cyclase, which catalyzes the conversion of 2,3-oxidosqualene into cucurbitadienol, a common precursor for cucurbitacin synthesis. Previous studies focused on uncovering the Bi gene clusters in Cucurbitaceae, but their presence in other cucurbitacin-producing plants remained unexplored. Here, the evolutionary history of Bi genes and their clusters were investigated in twenty-one plant genomes spanning three families based on chemotaxonomy. Nineteen Bi genes were identified in fourteen Cucurbitaceae, four Begoniaceae, and one Aquilaria species. Phylogenetic analysis suggested that the genome of Aquilaria sinensis contained the earliest Bi gene clusters in this dataset. Moreover, the genomic analysis revealed a conserved microsynteny of pivotal genes for cucurbitacin biosynthesis in Cucurbitaceae, while interspersed Bi gene clusters were observed in Begoniaceae, indicating rearrangements during plant Bi gene cluster formation. The bitter gene in A. sinensis was found to promote cucurbitadienol biosynthesis in the leaves of Nicotiana benthamiana. This comprehensive exploration of plant Bi genes and their clusters provides valuable insights into the genetic and evolutionary underpinnings of cucurbitacin biosynthesis. These findings offer prospects for a deeper understanding of cucurbitacin production and potential genetic resources for their enhancement in various plants.

Effect of different pretreatments of Aquilaria malaccensis seeds for enhancement of germination rate

A few plant species of the Thymelaeceae family are highly valuable and demanding because they contain resinous oil in their stems, branches, and roots. From this plant, resinous oil is extracted through the distillation process. Traditionally and from the religious point of view, the oil has a higher potential in the manufacturing of perfume, incense sticks, smoke, and many other medicinal and religious purposes. It is a highly economic plant, so its conservation is very important. Aquilaria plants are propagated through seeds and the seeds are recalcitrant, i.e., they are chilling sensitive and also cannot be stored at room temperature because of their high moisture content. They are also called desiccation sensitive. Below a certain level of moisture content, their embryos become death or inviable. Conservation of germplasm in the case of recalcitrant seeds is a major issue to be solved in the current situation. Our main focus was to enhance the germination of the Aquilaria malaccensis seeds for the early development of the seedlings within a short time. Here we are applying different pretreatments of Aquilaria seeds, such as Acetone for 1 min, 2 min, and 3 min, likewise Methanol, Ethanol, hot water, acetic acid, etc for enhancing seeds germination and it was found that highest germination percentage in the treatment where seeds are soaked in 1 min acetone (70%) in comparison to the control, which shows only a 56.7% germination rate. Their germination rate was determined by regular observation for up to 2 months, and the growth curve was also prepared by calculating the weight of the seeds. The findings of the current study will help to develop a protocol for early germination as well as mass propagation within a short period of time. The results of the Aquilaria species are significantly different from each other.

Characterization and phylogenetic analysis of complete chloroplast genome of cultivated Qinan agarwood

"Tangjie" leaves of cultivated Qinan agarwood were used to obtain the complete chloroplast genome using high-throughput sequencing technology. Combined with 12 chloroplast genomes of Aquilaria species downloaded from NCBI, bioinformatics method was employed to determine the chloroplast genome characteristics and phylogenetic relationships. The results showed that the chloroplast genome sequence length of cultivated Qinan agarwood "Tangjie" leaves was 174 909 bp with a GC content of 36.7%. A total of 136 genes were annotated, including 90 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. Sequence repeat analysis detected 80 simple sequence repeats(SSRs) and 124 long sequence repeats, with most SSRs composed of A and T bases. Codon preference analysis revealed that AUU was the most frequently used codon, and codons with A and U endings were preferred. Comparative analysis of Aquilaria chloroplast genomes showed relative conservation of the IR region boundaries and identified five highly variable regions: trnD-trnY, trnT-trnL, trnF-ndhJ, petA-cemA, and rpl32, which could serve as potential DNA barcodes specific to the Aquilaria genus. Selection pressure analysis indicated positive selection in the rbcL, rps11, and rpl32 genes. Phylogenetic analysis revealed that cultivated Qinan agarwood "Tangjie" and Aquilaria agallocha clustered together(100% support), supporting the Chinese origin of Qinan agarwood from Aquilaria agallocha. The chloroplast genome data obtained in this study provide a foundation for studying the genetic diversity of cultivated Qinan agarwood and molecular identification of the Aquilaria genus.

DNA barcoding identification of IUCN Red listed threatened species in the genus Aquilaria (Thymelaeaceae) using machine learning approaches

Aquilaria Lam. is a remarkable genus that produces agarwood, which is widely used as an herbal medicine, perfume, and incense sticks, as well as in interior decoration. However, illegal harvesting pose threats to endangered Aquilaria species, and the adulteration in agarwood products causes potential medical safety. In this study, 306 authentic sequences of five candidate barcodes (ITS, matK, psbA-trnH, rbcL, and trnL-trnF) downloaded from GenBank and 330 sequences taken from our samples were collected to establish a DNA barcode reference dataset for 11 species of Aquilaria listed in the IUCN Red List of Threatened Species. Machine learning approaches, including BLOG, Naïve Bayes, SMO, Jrip, and J48, were compared with distance-based (TaxonDNA) and tree-based (neighbor-joining tree [NJ tree]) methods based on the accuracy of discrimination across the five single barcodes and their combinations. The results indicated that BLOG and SMO could successfully identify the six species of Aquilaria with ITS + matK, ITS + rbcL, and ITS + trnL-trnF. However, when TaxonDNA and the NJ tree were used, only ITS + matK could identify these six species. Additionally, greater species resolution was found in machine learning approaches (16.67%−66.67%) compared with classical methods (0–50%) in managing low variation barcodes, such as psbA-trnH, and chloroplast-locus combinations. Compared with traditional analytical methods, machine learning approaches are reliable and efficient tools for DNA barcoding analysis of Aquilaria, which can be utilized to combat the adulteration of agarwood products and facilitate the conservation of Aquilaria species.

Genetic relationship and source species identification of 58 Qi-Nan germplasms of Aquilaria species in China that easily form agarwood.

Recently, Qi-Nan germplasm, the germplasm of Aquilaria species that easily forms agarwood, has been widely cultivated in Guangdong and Hainan Provinces in China. Since the morphological characteristics of Qi-Nan germplasm are similar to those of Aquilaria species and germplasm is bred by grafting, it is difficult to determine the source species of this germplasm by traditional taxonomic characteristics. In this study, we performed a DNA barcoding analysis of 58 major Qi-Nan germplasms as well as Aquilaria sinensis, A. yunnanensis, A. crassna, A. malaccensis and A. hirta with 5 primers (nuclear gene internal transcribed spacer 2 (ITS2) and the chloroplast genes matK, trnH-psbA, rbcL and trnL-trnF). This field survey in the Qi-Nan germplasm plantations in Guangdong and Hainan Provinces aimed to accurately identify the source species of Qi-Nan germplasm. According to the results, ITS2 and matK showed the most variability and the highest divergence at all genetic distances. This ITS2+matK combination, screened for with TaxonDNA analysis, showed the highest success rate in species identification of the Qi-Nan germplasm. Clustering in the phylogenetic trees constructed with Bayesian inference and maximum likelihood indicated that the Qi-Nan germplasm was most closely related to A. sinensis and more distantly related to A. yunnanensis, A. crassna, A. malaccensis and A. hirta. Therefore, this study determined that the source species of the Qi-Nan germplasm is A. sinensis.

The Chemistry of Agarwood Odorants.

The phytochemistry of the fragrant infected heartwood of Aquilaria and Gyrinops species, agarwood (oud), is critically reviewed, highlighting the use of this remarkable natural raw material in perfumery. The chemistry of the two main groups of constituents of agarwood (sesquiterpenoids and chromones) is discussed, focusing particularly on the former structural type. The identities of the main key odorants of agarwood essential oil and of the smoke produced by heating the wood of agarwood are also discussed.

A Review of Aquilaria malaccensis Propagation and Production of the Secondary Metabolite from Callus

Aquilaria is an evergreen non-timber agarwood obtained from the 15 species of Aquilaria belonging to the family Thymelecea. There are two species endemic to Northeast India, A. malaccensis and A. khasiana. A. malaccensis generate a high-grade degree of resin as compared to the other Aquilaria species, and it contributes to the economy of the Northeast states of India and the country as a whole. Due to its profoundly valuable sources, it is overexploited, which impacted its availability in genetic environments. The cultivation of the tree is challenging due to some environmental factors like the sensitivity of the seeds to desiccation, high light intensity, low shelf life, slow growth rate, and the effect of insects and microorganisms. Therefore, conservation and proliferation are urgently required for environmental sustainability and prevention from the stage of extinction. The objective of this paper is to compile the major research works on the conservation, production of the secondary metabolite from callus of A. malaccensis and updated information on its developments and approaches that are rapidly taking place in recent years so that further novel research can be envisaged.

Aquilaria Species (Thymelaeaceae) Distribution, Volatile and Non-Volatile Phytochemicals, Pharmacological Uses, Agarwood Grading System, and Induction Methods.

Agarwood is a highly valuable fragrant wood of Aquilaria spp. (Thymelaeaceae) which has been widely utilized in traditional medicine, religious rites, and cultural activities. This study summarizes a review on the identification of Aquilaria cultivars, volatile and non-volatile phytochemicals, pharmacological uses, and agarwood grading system to determine its quality, and different agarwood induction methods. Due to the highly demanding and depleted natural resources, the research on agarwood is still insufficient, and it has broad research and development prospects in many industries. However, due to the significant scientific nature of agarwood application, developing high-quality products and drugs from agarwood have become highly important, while no one has discussed in detail the phytochemicals uses and provided a summary until now. The main phytochemicals of agarwood include terpenoids, dominated by sesquiterpenes. For centuries, terpenoids have been used in traditional Chinese medicine and have been shown to possess various pharmacological properties, including bacteriostatic, antibacterial, sedation, analgesia, anti-inflammation, anti-asthmatic, hypoglycemic, antidepressant, and many others. Alongside biological activity screening, phytochemical advances and pharmacological research have also made certain progress. Therefore, this review discusses the research progress of agarwood in recent years and provides a reference basis for further study of Aquilaria plants and agarwood.

GC-MS analysis of young and mature wild agarwood leaves (Aquilaria malaccensis Lamk) and its antioxidant potential

Agarwood grows wildly in the nature and its leaves may be utilized as raw materials for agarwood tea, especially from Aquilaria species. The study was conducted to determine the chemical compounds in the young and mature leaves of wild gaharu (Aquilaria malaccensis Lamk). Chemical compounds were detected using pyrolysis gas chromatography mass spectrometry (py-GCMS) while antioxidant capacity of the leaf extracts was assayed using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical method. The results obtained a total of 30 chemical compounds in agarwood leaves extract with different composition between young and mature leaves. The agarwood leaves extracts displayed strong antioxidative capacity with a main compound namely octadecanoid acid or stearic acid.

Articulating Fragrant Agarwood Formation as an Outcome of the Interaction between the Insect Zeuzera conferta and Aquilaria trees – A Review

Agarwood is the resinous infected wood obtained from Aquilaria species, which is a highly priced product in the flavour and fragrance market. Its formation is a complex process of interaction between the plant, insect, and microorganisms. Multiple studies concerning the interaction of microorganisms with the Aquilaria tree have been reported. However, the significant interaction between the insect Zeuzera conferta Walker (Lepidoptera: Cossidae) with Aquilaria has been overlooked, and only exiguous studies have been accomplished. Considering the dearth of available literature on this interesting phenomenon a review has been attempted. The taxonomical and morphological descriptions proffered by researchers and the insect life cycle are discussed. The review lays emphasis on the chemical ecology of the interaction between Z. conferta, Aquilaria and associating microorganisms as a possible continuum operating in the form of complex chemical signalling via release and sensing of Volatile Organic Compounds (VOCs), Herbivore Induced Plant Volatiles (HIPVs) and Microbial Volatile Organic Compounds (MVOCs). The review also scrutinizes the future perspectives of understanding the interaction in devising suitable management strategies to prevent uncontrolled infestation and, simultaneously, develop artificial rearing technology for the insect Z. conferta as a strategy for ensuring sustainable livelihood of farmers dependent on agarwood production.

Inclusive Scenario of Natural Products Obtained From Agar Plant (Aquilaria SP.) In Bangladesh- A Review

Agarwood is the resinous heartwood obtained from the injured parts of trees under Thymelaeaceae family particularly from Aquilaria species. Agarwood is considered as the most prized non-timber forest product (NTFP) used in attars as well as medicines. Quality of agarwood is the determiner for defining its commercial value. Different countries use different grading system to explain the quality of agarwood. In Bangladesh, more than 45 compounds have been identified so far, mostly sesquiterpenoids, alkanes, fatty acid and other volatile aromatic compounds that are responsible for its fragrance and high prices. Ether extract, total phenolic contents, flavonoid, antioxidant and microbiological tests have shown tremendous positive results. Chemical profiling of agar products is the best identified using GC-MS technique by the various authors. Present review discusses the full scenario of Aquilaria production, inoculation, extraction methods, determination of agarwood quality and chemical constituents of agar oils and possibilities and barriers of this industry in Bangladesh. J. Bio-Sci. 29(2): 151-173, 2021 (December)

A REVIEW: AQUILARIA SPECIES AS POTENTIAL OF PHARMACOLOGICAL

One of the plants that is rich in benefits is from the genus Aquilaria spp. which is known to be able to produce agarwood resin. This genus includes 47 species, of which the four main species are Aquilaria malaccensis, Aquilaria subintegra, Aquilaria crassna and Aquilaria sinensis. Aquilaria species are known to have a wide spectrum of pharmacological activity and have been reported in many studies, including activity, anticancer, anti-inflammatory, AChE inhibitor (Acetylcholinesterase), anti-proliferative, and antidiabetic. The aim of this review is to expand information on the pharmacological activity of various Aquilaria species that can support future studies in the medical field of medicine.

Molecular identification of Aquilaria species with distribution records in China using DNA barcode technology

ABSTRACTS Aquilaria species is one of the main plant resources that produce agarwood, which containing black resin with important economic and medicinal values. There are about 15 species known to the genus around the world, but only two can be found in China, i.e. A. sinensis and A. yunnanensis. In this study, A. sinensis and A. yunnanensis that endemic respectively to Hainan and Yunnan were sampled, on the basis of the investigation and observation of their main morphological features in plantation. Five primers, i.e. ITS2, matK, trnL-trnF1, trnL-trnF2, and trnH-psbA, were eventually selected for DNA barcoding. The results showed that the seed surface of A. sinensis is smooth or sparsely pubescent, and the seed appendages were long. While the seed surface of A. yunnanensis is densely covered with yellow hairs and the seed appendages are short. The trnL-trnF1 sequence fragment has significant intraspecific and interspecific genetic distances. However, the species identification success rate of ITS2+matK combination was finally screened to be the highest, which was verified by the BBA method of TaxonDNA. The phylogenetic trees cluster analysis revealed that the classification of A. sinensis and A. yunnanensis is significant, and there is geographic isolation between the two species. Therefore, on the premise of accurate identification of plant morphological characters, ITS2+matK combination can be used to accurately identify the Aquilaria species in China.

Inhibition of pancreatic lipase by gallic acid and quercetin equivalent in ultrasonicated Malaysian grown Aquilaria spp. leaves of different particle size

Pancreatic lipase inhibitory compounds (gallic acid and quercetin) and their inhibition properties were determined in the crude extract of matured leaves from widely grown Aquilaria spp. in Malaysia, which are Aquilaria malaccensis and Aquilaria subintegra. The leaves were dried at 60 °C for 24 hours and undergone a pre-treatment method by using ultrasonication, within 30 minutes of reaction. Dried matured leaves were ground and sieved into particle sizes of 250, 300, 400, 500, and 1000 µm. Each particle size was soaked in distilled water with a ratio of 1% (w/v) for 24 hours, prior to ultrasonication process. Particle size of 250 µm resulted in the highest concentration of gallic acid and quercetin equivalent for both species of Aquilaria, wherein 89.99 mg/ml of gallic acid equivalent and 0.0295 mg/ml of quercetin equivalent were obtained in A. malaccensis crude leaves extract and in A. subintegra crude extract, 101.27 mg/ml and 0.0373 mg/ml were obtained, respectively. Thus, this sample was used in the inhibition study of pancreatic lipase. The concentrations of substrate and enzyme activity prepared were varied in the inhibition kinetics study. Based on the inhibition of pancreatic lipase, the crude leaves extract of both Aquilaria species exhibited the mixed-inhibition which is also known to be the non-competitive inhibition because the reaction mechanism showing the binding of inhibitor to the free pancreatic lipase and pancreatic lipase-substrate complex. This research is one of the fundamental works for future studies on the natural source to control obesity, which is a new direction of the key research in lipase inhibition.