As a valuable medicinal herb and spice, agarwood is widely used in the fields of daily chemistry, traditional medicine, religion and literary collection. It mainly contains sesquiterpenes and 2-(2-phenylethyl)chromones, which are often used to soothe the body and mind, relieve anxiety, act as an antidepressant and treat insomnia and other mental disorders, presenting a good calming effect. This paper reviews the chemical composition of the essential oils of different sources of agarwood, as well as the progress of research on the sedative and tranquilizing pharmacological activity and mechanism of action of agarwood essential oil (AEO), and then analyzes the current problems of AEO research and its application prospects in the treatment of mental diseases.

Four new 2-(2-phenylethyl)chromone derivatives (1–4) were isolated from the EtOH extract of Chinese agarwood produced via the whole-tree agarwood-inducing technique, coming from Aquilaria sinensis (Lour.) Spreng. (Thymelaeaceae). Their structures were elucidated by extensive spectroscopic methods, such as UV, IR, MS, 1D as well as 2D NMR. All of the isolates were then assessed for their anti-inflammatory activities on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7. Compound 1 exhibited significant inhibitory activity with an IC₅₀ value of 4.6 μM.

Agarwood, a precious traditional medicinal herb and fragrant material, is known for its sedative and sleep-improving properties. This study explores the mechanisms underlying the aromatherapy effects of Chi-Nan agarwood and ordinary agarwood in improving sleep. Using a combination of gas chromatography–mass spectrometry (GC-MS), network pharmacology, and molecular docking techniques, we identified and c ompared the chemical compositions and potential molecular targets of both types of agarwood. The GC-MS analysis detected 87 volatile components across six types of agarwood aromatherapy, with 51 shared between Chi-Nan and ordinary agarwood, while each type also had 18 unique components. Ordinary agarwood was found to be richer in sesquiterpenes and small aromatic molecules, whereas Chi-Nan agarwood contained higher levels of chromones. These differences in chemical composition are likely responsible for the distinct sleep-improving effects observed between the two types of agarwood. Through network pharmacology, 100, 65, and 47 non-repetitive target genes related to sleep improvement were identified for components shared by both types of agarwood (CSBTs), components unique to common agarwood (CUCMs), and components unique to Chi-Nan agarwood (CUCNs), respectively. The constructed protein–protein interaction (PPI) networks revealed that key targets such as MAOA, MAOB, SLC6A4, and ESR1 are involved in the sleep-improving mechanisms of agarwood aromatherapy. Molecular docking further confirmed the strong binding affinities of major active components, such as 5-Isopropylidene-6-methyldeca-369-trien-2-one and 2-(2-Phenylethyl)chromone, with these core targets. The results suggest that agarwood aromatherapy enhances sleep quality through both hormonal and neurotransmitter pathways, with ordinary agarwood more deeply mediating hormonal regulation, while Chi-Nan agarwood predominantly influences neurotransmitter pathways, particularly those involving serotonin and GABA. This study provides valuable insights into the distinct therapeutic potentials of Chi-Nan and ordinary agarwood, highlighting their roles in sleep improvement and offering a foundation for future research in the clinical application of agarwood-based aromatherapy.

The dried heartwood of Dalbergia odorifera is a very important traditional Chinese medicine. In nature, D. odorifera heartwood forms slowly over several decades, and excessive harvesting has caused large-scale reductions of its wild populations. To date, there have been no studies on artificial methods to induce heartwood formation in trees that have not already begun producing heartwood. We have published a patent for a whole-tree heartwood inducing technique for D. odorifera (the “Dodor-Wit” method); here, we describe and analyze its efficacy. Trees in four plantations in China were treated using this method. After two years, in 2016 and 2017, they were harvested and analyzed. Average heartwood yield per tree was 3,161.95 g. Heartwood induction rate (dry heartwood weight to total dry trunk weight after peeling) was 21.60%. Average volatile oil content per tree was 1.42%. Alcohol-soluble extract of the induced heartwood was 15.77%, exceeding the Chinese Pharmacopoeia standard. This is the first report on the Dodor-Wit method and heartwood induction in D. odorifera trees aged 5–8 years. The heartwood induced by Dodor-Wit satisfies the requirements of the Chinese Pharmacopoeia. The Dodor-Wit method has an important role in solving the extreme scarcity of Chinese medicinal herbs.

Agarwood formation is available only when agarwood-producing trees are wounded. As already evidenced, this process may be sped up when some fungi or their cultural metabolites are injected into these trees. In the present study, we developed a novel method called Trunk Surface Agarwood-Inducing Technique (Agar-Tst) to produce agarwood with fungi in two steps: uncover the bark, then spray or smear fungi suspension over the trunk surface. We used Agar-Tst to treat Aquilaria sinensis trees with two kinds of fungi, and evaluated agarwood formation after 6 months. Compared with the high-grade naturally formed agarwood as well as the 6,7-Dimethoxy-2-(2-phenylethyl) chromone standard, the agarwood produced by this technique showed similar spots in the thin layer chromatography assay. The agarwood yield was about 1100-1172 g per tree (eight-year old), with alcohol soluble extract content up to 37.3% and 38.9%, respectively, both above the requirement listed in Chinese Pharmacopoeia (10%). The six characteristic compounds of agarwood specified in Chinese Pharmacopoeia were also detected, and sesquiterpenes were determined by GC-MS to be the main compound in the essential oil of the produced agarwood. With the advantages of high yield, good quality and easy collection, especially no need to thoroughly destroy trees, the Agar-Tst method has been widely used for agarwood production in Hainan Province, China.