“The odor of traditional Chinese medicinal materials primarily comes from volatile and semi-volatile organic compounds, including terpenes, alcohols, esters, aldehydes and ketones, aromatic compounds, and small amounts of sulfur-containing and nitrogen-containing compounds.”

The odor and flavor produced by a complex mixture of chemical components with different amounts and thresholds constitute a unique property for food and Traditional Chinese Medicine (TCM). These compounds usually belong to mono- and sesquiterpenes, esters, lipids, and others. Existing techniques have been summarized for the analysis of taste and odor components and their characteristics.

The main components of volatile oils from traditional Chinese medicinal materials include terpenes, alcohols, esters, aldehydes, ketones, aromatic compounds, and a small amount of sulfur-containing and nitrogen-containing compounds.

Volatile components are the main active components of aromatic Chinese herbs. Aromatic Chinese herbs have been used to prevent plagues since ancient times. The paper discusses volatile oils from herbs containing compounds such as limonene, sabinene, citral, linalool, geraniol, and phytol, which are representative terpenoid and alcohol-type volatiles.

The main active components of Angelica dahurica are coumarins and volatile oil components. Modern pharmacological studies have shown that the volatile oil of A. dahurica has antioxidant, antiallergic, analgesic, and anticonvulsant activities. GC–MS analysis results showed that the six kinds of A. dahurica volatile oils mainly include five categories of compounds: alkanes, olefins, organic acids, esters and alcohols, among which alkanes have the highest content.

Our findings revealed that both wild O. sinensis and OS contain 11 distinct classes of volatile compounds, including aldehydes, ketones, nitrogen-containing heterocycles, alcohols, carboxylic acids, esters, aromatics, alkanes, oxygen heterocycles, amides, and olefins. However, the number of volatile components varied among sample types, with aldehydes, alcohols, ketones, nitrogen-containing heterocycles, and terpenes being the predominant compounds in OS. The volatile components of O. sinensis are the main constituents responsible for its ‘fishy odor’ and active ingredients, and they are also one of the important criteria for identifying the origin of O. sinensis in traditional methods.

GC–MS analysis showed that the volatile oil of Ligusticum chuanxiong contained 48 identified compounds, primarily phthalides, terpenoids, alcohols, aldehydes and ketones. The study notes that these volatile components are responsible for the unique odor and are important material bases of the herb's pharmacological activity.

The study identified and quantified sulfur‑containing volatile compounds in the bulb of Allium macrostemon. Using GC–MS, several sulfides and disulfides were detected as major volatile constituents. The authors state that these sulfur‑containing compounds contribute strongly to the characteristic garlic‑like odor of this traditional Chinese medicinal material.

Volatile components are the main active components of aromatic Chinese herbs. The odor and medicinal fragrance of aromatic traditional Chinese medicines are mainly attributed to volatile oil components, which are complex mixtures of terpenoids, aldehydes, ketones, esters, alcohols, and other small-molecule organic compounds. These volatile components are considered essential active ingredients in many TCM prescriptions.

Chinese herbal medicines often contain a mixture of volatile and semi-volatile compounds that contribute to their characteristic odor. Common classes discussed in the literature include terpenes, alcohols, esters, aldehydes, ketones, and aromatic compounds; trace sulfur- and nitrogen-containing compounds may also be detected.

The distinctive aroma of L. tsaoko is primarily attributed to its rich content of volatile organic compounds (VOCs), including monoterpenoids, sesquiterpenoids, and fatty acids, which have garnered attention due to their diverse biological activities. A barplot of the 30 most abundant compounds demonstrated the prevalence of terpenoids, indicating their significant contribution to the overall volatile compound composition. The identification of volatile compounds in L. tsaoko revealed terpenoids as the primary active components.

Terpenoids constitute the largest proportion, accounting for over 50%. After UAE processing, the concentration of almost all types of volatile compounds in AOF increased to varying degrees, especially for terpenoids. Due to their low odor threshold and pleasant aroma, they significantly affected the aroma of AOF.

In this study, volatile components from several commonly used medicinal herbs were analysed by HS‑SPME–GC–MS. The major constituents responsible for the characteristic odors were identified as terpenes and terpenoids, alcohols, aldehydes, ketones, esters, and aromatic compounds. Minor amounts of sulfur‑containing and nitrogen‑containing compounds were also detected and contributed to specific pungent or fishy notes in some samples.

According to the literature summary and analysis of Sichuan pepper pericarp oil, raw Sichuan pepper, and stir-fried pepper tallow’s main aroma compounds, they primarily consist of terpenes, alcohols, esters, aldehydes, and other substances. Linalool, γ‑terpinene, and D‑limonene were common substances found in all three samples, and were identified as key contributors to the overall aroma profile.

Headspace SPME combined with GC–MS was used to investigate volatile constituents in several Chinese medicinal materials. The volatile profiles were dominated by terpenes (monoterpenes and sesquiterpenes), alcohols, and aldehydes, followed by ketones and esters. In addition, small amounts of nitrogen‑containing heterocycles and sulfur‑containing compounds were identified, which contributed characteristic odor notes to specific herbs.

The article states: “Volatile components are a large class of substances with enormous numbers and diverse structures and biological activities. Natural components with very high medicinal value include alcohols, aldehydes, ketones, ethers, esters, carboxylic acids and other oxygen‑containing groups. They are usually volatile or semi‑volatile and are the main contributors to the fragrance and special odor of many traditional Chinese medicines. During processing, improper heating can lead to loss of these volatile components, thus weakening the characteristic aroma and efficacy.”

Gas chromatography–mass spectrometry analysis showed that the odor profiles of the processed products were mainly determined by volatile organic compounds such as terpenoids, aliphatic alcohols, esters, aldehydes, ketones and aromatic hydrocarbons. Nitrogenous and sulfurous volatiles were detected only in low abundance but could be associated with distinct pungent or fishy odors in some processed materials.

PubMed indexes many studies on aromatic and volatile constituents of Chinese medicinal materials, including terpenes, aromatic compounds, aldehydes, ketones, alcohols, esters, and sulfur-containing compounds. This is a useful primary-source gateway, but it does not itself state the claim; it shows that the topic is extensively studied in the biomedical literature.

The review explains that essential oils are complex mixtures of volatile compounds and commonly include monoterpenes, sesquiterpenes, oxygenated derivatives, alcohols, aldehydes, ketones, esters, phenolics, and sometimes sulfur-containing compounds. Although not specific to traditional Chinese medicinal materials, it provides strong biochemical context for the compound classes named in the claim.

The page states that volatile oils are mainly composed of terpene components, especially monoterpenes and sesquiterpenes and their oxygenated derivatives, plus aliphatic and aromatic components. It also says volatile oils have a strong characteristic odor and can contain small-molecule compounds such as alcohols, aldehydes, ketones, and acids.

Background knowledge: In pharmacognosy and herbal chemistry, the characteristic smell of many traditional Chinese medicinal materials is usually attributed to essential oils and other volatile constituents, especially terpenes, aromatic compounds, alcohols, aldehydes, ketones, esters, and sometimes sulfur- or nitrogen-containing molecules. This is general context rather than a direct citation.

The PDF states that volatile oils are a mixture and lists terpene compounds, aromatic compounds, and aliphatic compounds as the main components. It also includes oxygenated derivatives and mentions that some compounds are obtained through steam distillation or decomposition, which is consistent with the claim’s broad chemical categories.

This video discusses odour diagnosis in Traditional Chinese Medicine and the use of positive and negative descriptors of smell in Five Element acupuncture. It is relevant background on TCM odor concepts, but it does not provide analytical chemistry evidence for the specific compound classes in medicinal materials.