Synonym name: Terpinol; Terpineol 350
Catalogue No.: BP0158
Cas No.: 98-55-5
Formula: C₁₀H₁₈O
Mol Weight: 154.253
Botanical Source: Widely distributed in nature (>260 sources) as the chiral or racemic forms. Both stereoisomers occur widely in essential oils (Artemisia, Cinnamomum, Juniperus, Eucalyptus and Mentha spp.)

Purity: 95%~99%
Analysis Method: HPLC-DAD or/and HPLC-ELSD
Identification Method: Mass, NMR
Packing: Brown vial or HDPE plastic bottle
Can be supplied from milligrams to grams.

For Reference Standard and R&D, Not for Human Use Directly.
Inquire for bulk scale.

HPLC of Alpha-Terpineol

Storage conditions：Short-term storage at 2~8℃, long-term storage at -20 ~ -80℃

Introduction/Overview

Alpha Terpineol (CAS number: 98-55-5) is a natural terpenoid alcohol compound widely present in various plant essential oils, especially in Eucalyptus urophylla（Eucalyptus globulus The content in Labill is relatively abundant. As an important plant metabolite, alpha terpineol has attracted much attention due to its diverse biological activities, covering multiple fields such as anti-tumor, anti-inflammatory, antibacterial, antifungal, and neuroprotective effects. In recent years, with the in-depth development of natural product pharmacology, the pharmacological mechanism, molecular targets and pharmaceutical characteristics of α - terpineol have been gradually revealed, showing its potential application value in metabolic syndrome, infectious diseases, inflammatory pathological conditions, neuropathic pain and other diseases.

This article provides a systematic review of the chemical structure and physicochemical properties, plant sources, and extraction methods of alpha terpineol, with a focus on its pharmacological activity and mechanism of action. Combined with pharmacological evaluation and pharmacokinetic data, it explores its clinical application prospects and future research directions, aiming to provide comprehensive and authoritative reference materials for researchers in the field of natural product pharmacology.

Chemical structure and physicochemical properties

Alpha terpineol is a monoterpene alcohol with the chemical name prop-2-ol substituted at position 2 by 4-methylcyclohexene-3-en-1-yl. Its molecular formula is C10H18O and its molecular weight is 154.25. Structurally, α - terpineol contains a cyclohexene ring with one hydroxyl group and a 4-methyl substituent, and is a common monocyclic monoterpene alcohol in terpenoids. Its physical and chemical properties are as follows:

• Molecular weight: 154.25
• LogP value: 2.60, indicating that it has moderate lipid solubility, which is beneficial for membrane penetration and bioavailability
• Polar surface area (TPSA): 20.23 Å ², lower polarity helps it pass through the blood-brain barrier
• Number of hydrogen bond acceptors: 1, reflecting the presence of hydroxyl groups in its molecule
• Water solubility: 1.5 (relative value), indicating limited water solubility, requiring improvement in bioavailability through appropriate solvents or carriers
• High blood-brain barrier penetration ability suggests its potential role in the central nervous system

Toxicological data shows that the LD50 of alpha terpineol is approximately 4300 mg/kg, indicating its low acute toxicity. The liver toxicity, cardiac toxicity, and hERG channel inhibition experiments were all negative, and the Ames mutagenicity test also showed no mutagenicity, indicating its high safety and good potential for drug development.

Plant sources and extraction methods

Alpha terpineol is widely present in the essential oils of various aromatic plants, especially eucalyptus（Eucalyptus globulus The content in Labill is relatively significant. In addition, alpha terpineol can also be detected in plants such as pine needles, lavender, lemon eucalyptus, basil, and thyme. Its main form of existence is free monoterpene alcohols, which participate in plant defense mechanisms and signal transduction as secondary metabolites.

The extraction method mainly relies on the distillation technology of plant essential oils, including steam distillation and volatile solvent extraction. In recent years, in order to improve extraction efficiency and purity, supercritical CO2 extraction technology and microwave-assisted extraction methods have gradually been applied to the extraction of alpha terpineol. The selection of extraction process has a significant impact on the quality and biological activity of the product, and optimizing extraction conditions is the key to achieving industrial production.

The purification steps usually use techniques such as column chromatography and high-performance liquid chromatography (HPLC) to ensure the acquisition of high-purity alpha terpineol to meet the needs of pharmacological research and clinical applications.

Pharmacological activity research

Antitumor activity

Numerous in vitro and in vivo studies have confirmed that alpha terpineol has significant anti-tumor activity. Its main mechanism of action is to inhibit the nuclear factor kappa B (NF - κ B) signaling pathway, block tumor cell proliferation, and promote apoptosis. As a key transcription factor for tumor cell survival, proliferation, and anti apoptosis, the inhibition of NF - κ B activity is of great significance for tumor treatment. Alpha sitosterol can reduce the nuclear translocation of NF - κ B and the expression of downstream inflammatory factors and anti apoptotic proteins, thereby inhibiting the growth of tumor cells.

In addition, some studies have shown that alpha terpineol can regulate the p38 MAPK and ERK signaling pathways, further affecting the expression of cell cycle and apoptosis related proteins, and enhancing anti-tumor effects.

anti-inflammatory activity

Alpha terpineol has a significant inhibitory effect on inflammatory response. It inhibits the production of inflammatory mediators (such as TNF - α, IL-1 β, IL-6, etc.) in human macrophages stimulated by lipopolysaccharide (LPS) by interfering with the NF - κ B, p38 MAPK, and ERK MAPK pathways, thereby reducing the inflammatory response. This mechanism of action lays the foundation for its potential therapeutic value in various inflammatory diseases.

Animal experiments have shown that alpha terpineol can alleviate tissue damage in inflammatory models and reduce the expression of inflammatory factors, indicating its good anti-inflammatory therapeutic potential.

Antibacterial and antifungal activity

α - terpineol exhibits inhibitory effects on various pathogenic bacteria and fungi, especially exhibiting strong antibacterial activity against periodontal disease associated bacteria and cariogenic bacteria. Its antibacterial mechanism may involve disrupting the integrity of bacterial cell membranes, interfering with cellular metabolism and protein synthesis.

In addition, alpha terpineol has an effect on fungi such as Trichophyton mentagrophytes Exhibiting antifungal activity, it can cause irreversible fungal cell division and inhibit fungal growth. This characteristic makes it potentially valuable for the prevention and treatment of skin fungal infections and oral infections.

Neuroprotection and neuropathic pain resistance activity

Alpha terpineol has excellent blood-brain barrier penetration ability, demonstrating its potential to play a role in the central nervous system. Related studies have shown that alpha terpineol can alleviate neuropathic pain and reduce neuroinflammatory responses, possibly by regulating the expression of neurotransmitters and inflammatory mediators.

Its anti-inflammatory and antioxidant properties also provide a theoretical basis for neuroprotection, and are expected to be applied in the treatment of neurodegenerative diseases and chronic pain.

Other pharmacological effects

Alpha terpineol exhibits a certain regulatory effect in metabolic syndrome related diseases. By activating AMPK and regulating metabolism related targets such as PPAR γ, α - terpineol may improve lipid metabolism abnormalities and insulin resistance, and has potential intervention value for metabolic diseases.

In addition, α - terpineol has been studied for various diseases such as diarrhea, infection, and inflammation, demonstrating broad pharmacological activity and application prospects.

Mechanism of action and molecular targets

The multiple pharmacological effects of alpha terpineol are attributed to its regulation of multiple signaling pathways and molecular targets:

• NF - κ B pathway As a major inflammatory and tumor related signaling pathway, α - terpineol exerts anti-inflammatory and anti-tumor effects by inhibiting the degradation of I κ B α, preventing NF - κ B nuclear translocation, reducing the expression of inflammatory factors and anti apoptotic proteins.
• MAPK pathway (p38 and ERK)α - terpineol regulates the phosphorylation status of p38 and ERK, affecting cell proliferation, apoptosis, and inflammatory response.
• AMPK（PRKAA1）As a key regulatory factor of energy metabolism, the activation of AMPK helps to improve the pathological state related to metabolic syndrome, and α - terpineol may regulate lipid and glucose metabolism by activating AMPK.
• PPARγRegulating lipid metabolism and inflammatory response, the regulation of PPAR γ by α - terpineol contributes to its application in metabolic syndrome.
• ALOX15 and ALOX5 Members of the lipoxygenase family participate in the generation of inflammatory mediators, and the regulation of alpha terpineol helps alleviate inflammation.
• NFE2L2（Nrf2）Regulating antioxidant response, α - terpineol may enhance cellular antioxidant capacity by activating the Nrf2 pathway.
• CNR1 (cannabinoid receptor 1)The effect of alpha terpineol on this receptor, which participates in neuroprotection and pain regulation, may explain its neuropathic pain relief effect.
• TNF As an important inflammatory mediator, alpha terpineol inhibits the expression of TNF and reduces inflammatory response.
• SHBG and NR1I2 Involving hormone regulation and drug metabolism, it suggests that alpha terpineol may affect endocrine and drug metabolism processes.

In summary, α - terpineol achieves its broad pharmacological activity through the synergistic action of multiple targets and pathways.

Evaluation of drug properties and pharmacokinetics

Alpha terpineol has good medicinal properties:

• safety LD50 up to 4300 mg/kg, with low acute toxicity; No hepatotoxicity, cardiotoxicity, hERG channel inhibition, Ames test negative, showing good safety and genetic toxicology characteristics.
• Physicochemical properties Moderate lipid solubility (LogP 2.6) and low polarity surface area are beneficial for cell membrane penetration and oral absorption.
• Blood-brain barrier penetration The high penetration ability makes it have potential applications in neurological diseases.
• Water solubility Low water solubility may limit its bioavailability and needs to be improved through formulation technology.
• pharmacokinetics Currently, research on the in vivo absorption, distribution, metabolism, and excretion (ADME) of alpha terpineol is relatively limited. Previous studies have suggested that after oral administration, it can effectively enter the bloodstream and be widely distributed in tissues, especially in brain tissue. Metabolic pathways may involve liver oxidation and binding reactions.

In the future, it is necessary to strengthen systematic research on the in vivo metabolism kinetics of alpha terpineol to guide clinical dose design and optimization of dosing regimens.

Clinical application prospects and prospects

Alpha terpineol has shown broad clinical application prospects due to its diverse pharmacological activities and good safety:

• Antitumor therapy As a natural NF - κ B inhibitor, alpha terpineol can serve as an adjuvant anti-tumor drug, especially with potential in inflammation related tumors.
• Anti inflammatory diseases Suitable for the treatment of chronic inflammatory diseases, such as rheumatoid arthritis, inflammatory bowel disease, etc.
• Antibacterial and antifungal properties Can be developed as oral care products for the prevention and treatment of periodontal disease and dental caries, especially with outstanding application value in anti MRSA cleaning agents.
• Neurological disorders Its anti neuropathic and neuroprotective effects provide new ideas for the treatment of neuropathic pain and neurodegenerative diseases.
• Metabolic syndrome and related diseases: It is expected to be used for the comprehensive management of obesity, diabetes and abnormal lipid metabolism by regulating AMPK and PPAR γ and other targets.

Future research should focus on preclinical pharmacokinetic evaluation, formulation development, and clinical trials of alpha terpineol to further validate its safety and efficacy. Meanwhile, based on its multi-target mechanism of action, explore combination therapy strategies to enhance therapeutic efficacy.

Conclusion

As a widely sourced and biologically active natural terpenoid alcohol, alpha terpineol has demonstrated significant pharmacological value in various fields such as anti-tumor, anti-inflammatory, antibacterial, neuroprotective, and metabolic regulation. Its good safety and drug properties have laid a solid foundation for clinical application. In the future, with the in-depth analysis of pharmacological mechanisms and advances in formulation technology, alpha terpineol is expected to become an important candidate molecule in the development of natural product drugs, providing new drug options for the treatment of various diseases.

Continuous basic and clinical research will drive alpha terpineol from the laboratory to clinical practice, promote the development and innovation of natural product pharmacology, and benefit a wide range of patients.