Abstract—

Hydrodistillation (HD), steam distillation (SD) and microwave-assisted hydrodistillation (MAHD) extraction methods were assessed for their effects on yield, chemical composition and antimicrobial activity of essential oils from Distichochlamys citrea M.F. Newman rhizomes. The greatest essential oil yields (v/w on dry weight basis) were obtained by MAHD (0.37%), followed by HD (0.27%) and SD (0.25%). The extraction time of MAHD was 1 h, compared to 4 h for HD and SD. Gas chromatography and gas chromatography-mass spectrometry were used to analyze the obtained oils. Geranial, neral, α-terpineol, 1,8-cineole, β-pinene and α-pinene were the major components in all oil samples. MAHD resulted in an increase in the content of oxygenated monoterpenes in the essential oil compared to HD or SD. Antimicrobial activity of essential oils was evaluated in terms of minimum inhibitory concentrations (MICs) by the microdilution broth method. All essential oils showed varying degrees of antimicrobial activity, with MICs ranging from 200 to 400 μg/mL. These results indicate that extraction method significantly influences the yield, chemical composition and antimicrobial activity of essential oils from D. citrea rhizomes. Compared with HD and SD methods, MAHD has the advantages of shorter extraction time, increased yield and increased oil quality. Therefore, MAHD is proposed as the preferred method for extracting essential oils from D. citrea rhizomes.

中文翻译：

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不同提取方法获得的柞蚕根茎精油的产量、化学成分和抗菌活性比较

摘要——

评估了加氢蒸馏 (HD)、水蒸气蒸馏 (SD) 和微波辅助加氢蒸馏 ( MAHD ) 提取方法对柑橘花香精油的产量、化学成分和抗菌活性的影响MF 纽曼根茎。MAHD (0.37%) 获得最大的精油产量 (v/w 基于干重)，其次是 HD (0.27%) 和 SD (0.25%)。MAHD 的提取时间为 1 小时，而 HD 和 SD 的提取时间为 4 小时。使用气相色谱和气相色谱-质谱分析获得的油。Geranial、neral、α-萜品醇、1,8-桉树脑、β-蒎烯和α-蒎烯是所有油样中的主要成分。与 HD 或 SD 相比，MAHD 导致精油中含氧单萜的含量增加。通过微量稀释肉汤法根据最低抑菌浓度 (MIC) 评估精油的抗菌活性。所有精油都显示出不同程度的抗菌活性，MIC 范围为 200 至 400 μg/mL。D. citrea根茎。与 HD 和 SD 方法相比，MAHD 具有提取时间短、产量增加、油质提高等优点。因此，建议将 MAHD 作为从D. citrea根茎中提取精油的首选方法。