Chemistry of Natural Compounds Department, National Research Center, 33 El Bohouth St., Dokki, Giza, 12622, Egypt.
Pharmacognosy Department, Faculty of Pharmacy, Cairo University, Cairo, 12613, Egypt.
Chem Biodivers. 2021 Jul;18(7):e2100238. doi: 10.1002/cbdv.202100238. Epub 2021 Jun 7.
Plants belonging to Euphorbia L. genus are considered very interesting from a medicinal point of view due to their diverse metabolites and bioactivities. The essential oil (EO) of Euphorbia mauritanica L. is not studied up to date. Therefore, the present study aimed to explore the chemical profile of this EO and evaluate its antioxidant, cytotoxic, and allelopathic potentialities. The EO was extracted from the whole plant via hydrodistillation and then, analyzed by gas chromatography/mass spectrometry (GC/MS). The correlation of E. mauritanica with the other Euphorbia plants was established using chemometric analysis. The antioxidant activity was determined based on scavenging of the free radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The anti-proliferation of the EO on the Hep G2 and MCF-7 cells was evaluated. Finally the allelopathic activity of the EO was assessed against the two noxious weeds, Dactyloctenium aegyptium and Urospermum picroides. Forty-one compounds were identified using GC/MS analysis, with an abundance of terpenoids (91.54 %) that were categorized into mono- (30.75 %), sesqui- (15.23 %), and diterpenes (45.56 %). Interestingly, the results revealed the preponderance of diterpenoid constituents although they are rarely found in the EOs of the plant kingdom. The major compounds were (3E)-cembrene A (18.66 %), verticiol (17.05 %), limonene (7.91 %), eucalyptol (7.26 %), α-pinene (5.61 %), neo-cembrene A (3.52 %), kaur-16-ene (3.24 %), and cembrene (3.09 %). The EO showed moderate antioxidant activity where it attained IC values of 83.34 and 64.21 μg mL for DPPH and ABTS compared to 23.01 and 19.23 μg mL for ascorbic acid as standard, respectively. The EO exhibited very weak cytotoxic effect on MCF-7 and Hep G2 cells. The EO showed significant allelopathic activities against the weeds D. aegyptium and U. picroides in a concentration-dependent manner. EO was found more effective against U. picroides than D. aegyptium with IC values of 0.79, 0.45, and 0.67 mg mL and 1.17, 0.55, and 1.08 mg mL for germination, root, and shoot growth, respectively. Due to the high content of diterpenes in E. mauritanica, further study is recommended for more characterization of pure forms of the identified diterpenes as well as evaluating their bioactivity either solely or synergistically.
从药用角度来看，大戟属植物因其多样化的代谢物和生物活性而备受关注。目前尚未对摩洛哥大戟（Euphorbia mauritanica L.）的精油（EO）进行研究。因此，本研究旨在探索这种 EO 的化学成分，并评估其抗氧化、细胞毒性和化感潜力。通过水蒸气蒸馏法从整株植物中提取 EO，然后通过气相色谱/质谱联用仪（GC/MS）进行分析。利用化学计量学分析方法建立了摩洛哥大戟与其他大戟属植物的相关性。抗氧化活性基于自由基清除、1,1-二苯基-2-苦基肼（DPPH）和 2,2'-联氮-双（3-乙基苯并噻唑啉-6-磺酸）（ABTS）的测定来确定。评估了 EO 对 Hep G2 和 MCF-7 细胞的增殖抑制作用。最后，评估了 EO 对两种有害杂草，刺蒺藜草和南非滨藜的化感活性。通过 GC/MS 分析鉴定出 41 种化合物，其中萜类化合物（91.54%）含量丰富，分为单萜（30.75%）、倍半萜（15.23%）和二萜（45.56%）。有趣的是，尽管二萜类成分在植物界的精油中很少见，但结果显示它们占优势。主要化合物为（3E）-喇叭茶烯 A（18.66%）、Verticiol（17.05%）、柠檬烯（7.91%）、桉叶醇（7.26%）、α-蒎烯（5.61%）、新喇叭茶烯 A（3.52%）、贝壳杉-16-烯（3.24%）和喇叭茶烷（3.09%）。EO 表现出中等的抗氧化活性，其 DPPH 和 ABTS 的 IC 值分别为 83.34 和 64.21μg/mL，而抗坏血酸的 IC 值分别为 23.01 和 19.23μg/mL。EO 对 MCF-7 和 Hep G2 细胞的细胞毒性作用非常弱。EO 对杂草刺蒺藜草和南非滨藜表现出显著的化感活性，呈浓度依赖性。与刺蒺藜草相比，EO 对南非滨藜的效果更显著，其 IC 值分别为 0.79、0.45 和 0.67mg/mL，0.11、0.55 和 1.08mg/mL，用于发芽、根和芽生长。由于摩洛哥大戟 EO 中二萜类化合物含量较高，建议进一步研究鉴定出的二萜类化合物的纯形式，以及评估它们的生物活性，无论是单独使用还是协同使用。
