STYRAX Liquidambar orientalis

What is Liquidambar orientalis?

According to the World Checklist of Vascular Plants (WCVP, Kew), in the extract read on 21/09/2026, Liquidambar orientalis Mill. is a name of rank “Species” with status “Accepted”, placed in the family Altingiaceae (identifier 500214).

How was the styrax of the Huang study obtained?

Where were the grafted trees of the study grown?

According to Huang et al. (2024), buds of L. orientalis Mill. were grafted as scions onto rootstocks and cultivated in China at Nanjing (Jiangsu), Cangwu (Guangxi), Changning (Yunnan), and at Fuyang, Jinyun, Jiashan and Tonglu (Zhejiang). The authors state that grafted L. orientalis Mill. can produce styrax after 5–10 years, a styrax they name “grafted styrax” (SG).

Which styrax samples did the study compare?

The “styrax standard” sample (SS) was obtained from the China National Institute for Food and Drug Control, in Beijing. The “commercially available styrax” sample (SC) was bought at the Bozhou medicinal material market (Anhui, China) and identified by Professor Lu-Ping Qin, of Zhejiang Chinese Medical University. The “grafted styrax” sample (SG) was collected from grafted L. orientalis Mill. growing at the Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing, China), and prepared according to a description in the literature.

How were the samples analysed?

For the analysis, 50 mg of styrax were dissolved in 5 mL of anhydrous ethanol; 3 mg each of cinnamyl cinnamate and 3-phenylpropyl cinnamate, as reference substances, were dissolved in 1 mL of anhydrous ethanol each, and all the solutions were filtered through a 0.22 μm membrane. The GC-MS system comprised a 7890B gas chromatograph, an Agilent 5977A MSD detector and a 7693 autosampler (HP-5, 30 m × 0.25 mm, 0.25 μm film); the scan range was m/z 35–500, with split injection (ratio 10:1), a nitrogen flow of 0.7 mL/min and an injected volume of 1 μL. The mass spectrometer worked in electron ionisation (EI) mode at 70 eV, with the source at 230 °C and the transfer line at 280 °C; the oven was held for 5 min at 60 °C, raised to 280 °C at 4 °C/min, then held for 10 min at 280 °C. The compounds were identified from the characteristic peaks of the total ion current chromatogram, by searching the NIST14 database and by comparison with the controls. The cinnamic acid content after alkaline hydrolysis of the styrax was determined by high-performance liquid chromatography according to the Chinese Pharmacopoeia (general rule 0512).

What does the styrax of the Huang study contain?

According to Huang et al. (2024), a total of 59 chemical components were identified in the styrax.

Twenty-four chemical components were found in common in the three samples (SG, SC, SS). The three chromatograms were imported into the similarity evaluation system for the chromatographic fingerprint of traditional Chinese medicine to generate a control chromatogram; the similarity of SG and SC to this control chromatogram was close to 1.0, which, according to the authors, indicates a similar chemical composition of SG and SC. The proportion of the 12 main compounds, calculated on peak area, was 93.95% in the SG sample. It was 94.24% in the SC sample. It was 95.86% in the SS sample. The contents of cinnamyl cinnamate and 3-phenylpropyl cinnamate together amounted to about 81.43% in the SG sample, by the area normalisation method. Analysed according to the quality standard for styrax of the Chinese Pharmacopoeia 2020, the SG sample had a cinnamic acid content of 22.05%. Analysed in the same way, the SC sample had a cinnamic acid content of 21.89%.

Which values does Table 2 of the Huang study give?

In Table 2 of Huang et al. (2024), the “Styrene” row (styrene, CAS 100-42-5) carries 0.54% of peak area (GC-MS) in the SG sample. In the SC sample, the same row carries 1.05%. In the SS sample, it carries 0.90%. The “3-Phenyl-1-propanol” row (3-phenyl-1-propanol, CAS 122-97-4) carries 1.45% of peak area in SG. In SC, it carries 2.00%. In SS, it carries 1.54%. The “Cinnamyl alcohol” row (cinnamyl alcohol, CAS 4407-36-7) carries 2.52% of peak area in SG; the text of the paper names this peak “3-phenyl-2-propen-1-ol”. In SC, the “Cinnamyl alcohol” row carries 3.28%. In SS, it carries 2.48%. The “β-Caryophyllene” row (β-caryophyllene, CAS 87-44-5) carries 1.36% of peak area in SG. In SC, it carries 1.76%. In SS, it carries 1.61%. The “Cinnamyl benzoate” row (cinnamyl benzoate, CAS 117204-78-1 as written in the table) carries 0.70% of peak area in SG. In SC, it carries 0.80%. In SS, it carries 0.70%. The “Benzyl cinnamate” row (benzyl cinnamate, CAS 103-41-3) carries 2.31% of peak area in SG. In SC, it carries 2.46%. In SS, it carries 2.35%. The “Benzenepropanoic acid,3-phenylpropyl ester” row (CAS 60045-27-4) carries 1.12% of peak area in SG; the text of the paper writes “benzenepropanoic acid, 3-phenylpropyl ester”. In SC, the same row carries 1.05%. In SS, it carries 0.96%. The “Bornyl Cinnamate” row (bornyl cinnamate, CAS 6330-67-2) carries 0.12% of peak area in SG. In SC, it carries 0.10%. In SS, it carries 0.08%. The “Benzenepropanoic acid, 3-phenyl-2-propenyl ester” row (CAS 28048-98-8) carries 1.01% of peak area in SG. In SC, it carries 0.92%. In SS, it carries 0.72%. The “3-Phenylpropyl cinnamate” row (3-phenylpropyl cinnamate, CAS 122-68-9) carries 30.04% of peak area in SG. In SC, it carries 29.68%. In SS, it carries 31.79%. The “Cinnamyl cinnamate” row (cinnamyl cinnamate, CAS 122-69-0) carries 51.39% of peak area in SG. In SC, it carries 49.52%. In SS, it carries 51.40%. The “The others” row carries 4.80% of peak area in SG. In SC, it carries 4.37%. In SS, it carries 2.94%.

How was the essential oil of the İlhan study obtained from the balsam?

According to İlhan et al. (2026), the L. orientalis (storax) balsam used in the study was obtained from a local producer in Muğla, Türkiye. The essential oil was extracted from the balsam by hydrodistillation for 3 h in a Clevenger-type apparatus.

How was the oil analysed?

The GC-MS and GC-FID analyses were carried out at the Plant, Drug and Scientific Research Application and Research Center (AUBİBAM), Anadolu University, Eskişehir, Türkiye, on an Agilent 7890B GC system; for the chromatographic analysis, the oil was diluted to 10% (w/w) in hexane, and 1 μL was injected with a split ratio of 40:1. The relative composition was determined by GC-FID on an Agilent 7890B fitted with an HP-Innowax capillary column (60 m × 0.25 mm i.d., 0.25 µm film), injector and detector at 250 °C, oven programmed from 60 °C (10 min) to 220 °C at 4 °C/min (10 min) then up to 240 °C at 1 °C/min, with helium at a constant flow of 0.7 mL/min. The relative percentages of the constituents were calculated from FID peak areas, without correction factors. The compounds were identified by GC-MS (Agilent 7890B coupled to a 5977B MSD, EI mode at 70 eV, same chromatographic conditions, ion source at 230 °C, spectra recorded from 35 to 450 m/z), by comparing the spectra with the Wiley 9 and NIST 11 libraries, then the calculated linear retention indices (LRIc) with literature values (LRIr). According to the note of Table 1, the LRIc are “relative retention indices” calculated against n-alkanes (C7-C40) on a polar column, the percentages are relative and calculated from FID data, and “tr” denotes a trace (< 0.1).

What does the essential oil of the İlhan study contain?

According to İlhan et al. (2026), GC-MS analysis of the L. orientalis essential oil identified a total of 90 volatile constituents. In Table 1, the relative percentages of the constituents listed for the analysed oil total 98.9%.

According to the authors, aromatic compounds were the most abundant chemical group, with styrene (68.6%) detected as the predominant constituent. In Table 1, styrene (“Styrene”) was measured at 68.6% (relative percentage) in the analysed oil. Ethyl cinnamate (“Ethyl cinnamate” in Table 1) was measured at 6.8%; the text of the paper writes “(E)-ethyl cinnamate” for the same value. α-Pinene (“α-Pinene”) was measured at 5.9%. β-Pinene (“β-Pinene”) was measured at 2.9%. Torreyol (“Torreyol”) was measured at 1.6%. 4-Ethylphenol (“4-Ethyl phenol” in Table 1) was measured at 1.1%; the discussion of the paper writes “4-ethylphenol” for the same value. Benzenepropanol (“Benzene propanol”) was measured at 0.9%. Myrcene (“Myrcene” in Table 1) was measured at 0.7%; elsewhere the paper writes “β-myrcene”, without a value. Acetophenone (“Acetophenone”) was measured at 0.7%. Benzenepropanal (“Benzene propanal”) was measured at 0.7%. T-Cadinol (“T-Cadinol”) was measured at 0.7%. Germacrene D (“Germacrene D”) was measured at 0.6%. Limonene (“Limonene”) was measured at 0.5%. β-Cubebene (“β-Cubebene”) was measured at 0.5%. β-Copaene (“β-Copaene”) was measured at 0.5%. (E)-Cinnamaldehyde ("(E)-Cinnamaldehyde") was measured at 0.5%. Cinnamyl alcohol (“Cinnamyl alcohol”) was measured at 0.4%. Methyl eugenol (“Methyl eugenol”) was recorded as a trace (“tr”, that is < 0.1 according to the note of the table).

What does the IFRA Standard “Styrax” cover?

The IFRA Standard “Styrax” has the publication date 2020 (Amendment 49) and mentions earlier publications in 1977, 1994 and 2013. According to the standard, its recommendation is “PROHIBITION / RESTRICTION / SPECIFICATION”. The standard covers CAS numbers 8046-19-3, 8024-01-9, 94891-27-7, 94891-28-8 and 101227-15-0. Its scope includes, but is not limited to, these CAS numbers; any other CAS number used to identify this ingredient should be considered in scope as well, in the words of the standard (“should be […] considered in scope”). Under “Synonyms”, the standard lists “Styrax crude gums” under “Prohibition of the crude material”, and “Styrax resin”, “Styrax oil”, “Styrax oil, rectified” and “Styrax oil, pyrogenated, distilled” under “Restriction and Specification of the distillates”. Its implementation dates are 10 February 2021 for new creations and 10 February 2022 for existing creations; these dates apply only to the supply of fragrance mixtures (formulas), not to finished consumer products on the market.

What does the standard say about the crude material?

According to the standard, the Expert Panel for Fragrance Safety further recommends not to use “Styrax crude” “in any finished product […] application”, in the terms of the standard.

What does the standard say about the distillates and styrax oil?

According to the standard, the Expert Panel for Fragrance Safety reviewed the available data on styrax distillates and recommends limits for 12 product categories, which are the acceptable use levels of styrax distillates in those categories.

According to the standard, under “Fragrance ingredient restriction” (Note box), only extracts or distillates (resinoids, absolutes and oils) prepared from exudations of Liquidambar styraciflua L. var. macrophylla, which the WCVP lists as a synonym of Liquidambar styraciflua L., or of Liquidambar orientalis Mill. “can be used”, in the words of the standard.

Under “Fragrance ingredient specification”, the standard states that styrax oil can be obtained by solvent extraction or by pyrolysis. According to the standard, styrax oil obtained by pyrolysis “shall” be rectified according to Good Manufacturing Practices (GMP), and its content of polycyclic aromatic hydrocarbons (PAH) “shall” respect a requirement for which benzopyrene and 1,2-benzanthracene are the PAH markers. According to the standard, whether the oil is used alone or in combination with rectified Cade oil, rectified Birch tar oils or rectified Opoponax oil, the total concentration of both markers (benzopyrene and 1,2-benzanthracene) “should not” exceed 1 ppb in the final product.

Which hazard does the standard name, and on what is it based?

The intrinsic property driving risk management named by the standard is dermal sensitisation (“DERMAL SENSITIZATION”). The standard is based on at least one of the publications it lists, among them the RIFM safety assessment on styrax, if available at the RIFM Fragrance Material Safety Assessment Center.

References

• Govaerts R. (ed.), World Checklist of Vascular Plants (WCVP), Royal Botanic Gardens, Kew — https://sftp.kew.org/pub/data-repositories/WCVP/wcvp.zip
• Huang S., Cai J., Ma L., Zhang Q., Sun Y., Zhang Q., Qin L., « Effects of grafting on chemical constituents, toxicological properties, antithrombotic activity, and myocardial infarction protection of styrax secreted from the trunk of Liquidambar orientalis Mill », PLOS ONE 2024;19(1):e0289894, doi:10.1371/journal.pone.0289894 — https://www.ebi.ac.uk/europepmc/webservices/rest/PMC10769069/fullTextXML
• İlhan Z., Şıklaroğlu R., Gürses M., Bayezit M., Gürsoy T., Musabeşeoğlu Y., Erkan Ö., Musabeşeoğlu Ş., Karaca M., Akkan H.A., « Antibacterial, Synergistic, and Antibiofilm Activities of Liquidambar orientalis Mill. Essential Oil Against Clinically Relevant Bacterial Pathogens », Antibiotics 2026;15(9):851, doi:10.3390/antibiotics15090851 — https://www.ebi.ac.uk/europepmc/webservices/rest/PMC13603296/fullTextXML
• International Fragrance Association (IFRA), IFRA Standard « Styrax », Amendment 49, 2020 — https://d3t14p1xronwr0.cloudfront.net/docs/standards/IFRA_STD_078.pdf