Methysticin is a kavalactone originally found in Piper methysticum (kava plant). Methysticin exhibits neuroprotective, neuromodulatory, and antifungal activities. Methysticin may also display anti-inflammatory benefit, inhibiting activation of NF-κB in lung adenocarcinoma tissue. Methysticin activates Nrf2 in neurons and astroglia, protecting against amyloid-β (Aβ)-induced neurotoxicity. This compound displays antimicrobial efficacy against species of Fusarium, Trichoderma, and Colletotrichum. Additionally, methysticin inhibits peak amplitude of voltage-gated Na+ channels in hippocampal neurons. Methysticin administration activates the Nrf2 pathway and reduces neuroinflammation, hippocampal oxidative damage and memory loss in a mouse model of AD. Therefore, kavalactones might be suitable candidates to serve as lead compounds for the development of a new class of neuroprotective drugs.

4’-Methoxychalcone (4-MC) is chalcone derivative that has shown diverse pharmacological properties, including anti-tumor and anti-inflammatory activities. 4’-Methoxychalcone significantly enhances differentiation of preadipocytes, which is accompanied by the induction of adipogenic genes including PPARgamma and adiponectin. 4’-Methoxychalcone considerably upregulated PPARgamma-induced transcriptional activity and reversed the inhibitory effect of TNF-alpha on adipocyte differentiation and adiponectin expression. 4’-Methoxychalcone could be utilized for the prevention and treatment of metabolic syndrome and diabetes.

1,4-naphthoquinone is a chemical studied as a potential inhibitor of monoamine oxidase and DNA topoisomerase activities as well as acetyltransferase activity. 1,4-Naphthoquinone is a potent inhibitor of human cancer cell growth and angiogenesis.

Jatrorrhizine is an active component of the traditional Chinese herb Coptis chinensis, which has been used to prevent and treat metabolic disorders. It is also found plants such as Enantia chlorantha, Thalictrum lucidumm, Thalictrum revolutum. Jatrorrhizine possesses antifungal, antibacterial activity. It has low toxicity and was studied in mouse models of obesity and hypercholesterolemia. The mechanism of action of Jatrorrhizine is not fully elucidated. The compound blocks alpha-1 and alpha-2 adrenoreceptors, monoamine oxidase A and B.

Trihydroxychalcone (Isoliquiritigenin, ISL) is a flavonoid found in licorice root and several other plants that displays antioxidant,anti-inflammatory,and antitumor activities as well as hepatoprotection against steatosis-induced oxidative stress. Trihydroxychalcone is a potent antimetastatic agent, which can markedly inhibit the metastatic and invasive capacity of prostate cancer cells. The inhibition of JNK/AP-1 signaling may be one of the mechanisms by which ISL inhibits cancer cell invasion and migration. Trihydroxychalcone has been shown to be a BACE1 inhibitor, which could ameliorate memory impairment in mice, and is expected to be potentially used as a lead compound for further anti-AD reagent development.

β-phenylethylamine (2-phenylethylamine) is a small amine containing alkaloid synonymous with phenethylamine and the acronym PEA; in the human body it has a neuromodulator/neurotransmitter role and is known as a trace amine due to its low quantity relative to other bioactive amino acids. PEA was characterized as a substrate for type B monoamine oxidase. PEA functions by activating trace amine receptors (including TAAR1 and TAAR2) thereby regulating monoamine turnover. Ring-substituted phenethylamines, commonly known as 2Cs, are designer drugs that are emerging as new drugs of abuse. PEA administration may be therapeutic in selected depressed patients.

The tetrahydroisoquinoline nucleus is present in a number of compounds and drugs. Tetrahydroisoquinolines (THIQs), which belong to a group of cyclized condensation adducts of biogenic amines with aldehydes, are referred to as mammalian alkaloids. They include salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline; SAL) and tetrahydropapaveroline (6,7-dihydroxy-1-(3',4'-dihydroxybenzyl)-1,2,3,4-tetrahydroisoquinoline; THP) that are derived from dopamine through condensation with acetaldehyde and dopaldehyde (3,4-dihydroxyphenylacetaldehyde), respectively. THP is a putative dopaminergic neurotoxin that is implicated in the pathology of Parkinson's disease. It is known that THP is detected at a high level in the brain and the urine of parkinsonian patients under 3,4-dihydroxyphenylalanine (L-DOPA) therapy. In addition, significant levels of THP have also been detected in the brain after ethanol uptake and/or L-DOPA treatment, and this endogenous alkaloid is considered to account for the neurobehavioral abnormalities associated with alcoholism and may act as a neurotransmitter

Pargyline is an irreversible selective monoamine oxidase (MAO)-B inhibitor, which possesses higher selectivity to this isoform in comparison with MAO-A. It was approved under brand name eutonyl for the treatment hypertension, but then this drug was discontinued.