Tea tree hydrosol (TTH) is the aqueous phase of the distillate from the steam distillation process of the twigs and leaves of Melaleuca alternifolia. In this study, the chemical components of TTH were analyzed by gas chromatography–mass spectrometry (GC–MS) and gas chromatography–flame ionization detector (GC-FID). The major components were terpenoids (1.53 mg/mL), including monoterpenoids and sesquiterpenoids. The antibacterial activity of TTH was assessed by paper disc agar diffusion and broth dilution methods. Terpinen-4-ol (MIC: 0.31-0.62 mg/mL), 2-endo-hydroxy-1,8-cineole (MIC: 1.25-2.50 mg/mL) and p-menth-3-ene-1,2-diol (MIC: 0.62-2.50 mg/mL) were the main antibacterial components of TTH. The results showed that the major components of TTH and tea tree oil (TTO) had the same parent structures, but different degrees of oxidation. Terpinen-4-ol was the most abundant component in both TTH (624.2 μg/mL) and TTO (35-48%), and played a major role in antibacterial activities. This is the first report on the chemical components and antibacterial activities of TTH and their correlation with TTO, which demonstrates the potential application of TTH as a natural antimicrobial agent in health care products.

茶树纯露 (TTH) 是互叶白千层的枝叶水蒸气蒸馏过程中蒸馏出的水相。在本研究中，TTH 的化学成分通过气相色谱-质谱 (GC-MS) 和气相色谱-火焰电离检测器 (GC-FID) 进行分析。主要成分为萜类化合物（1.53 mg/mL），包括单萜类和倍半萜类。通过纸圆盘琼脂扩散和肉汤稀释方法评估 TTH 的抗菌活性。Terpinen-4-ol (MIC: 0.31-0.62 mg/mL), 2 - endo - hydroxy -1,8-cineole (MIC: 1.25-2.50 mg/mL) 和p-menth-3-ene-1,2-diol (MIC: 0.62-2.50 mg/mL) 是 TTH 的主要抗菌成分。结果表明，TTH和茶树油（TTO）的主要成分具有相同的母体结构，但氧化程度不同。Terpinen-4-ol 是 TTH (624.2 μg/mL) 和 TTO (35-48%) 中含量最丰富的成分，在抗菌活性中起主要作用。这是关于TTH的化学成分和抗菌活性及其与TTO的相关性的第一份报告，证明了TTH作为天然抗菌剂在保健品中的潜在应用。