Version 1
: Received: 1 July 2023 / Approved: 3 July 2023 / Online: 3 July 2023 (13:23:21 CEST)
Version 2
: Received: 25 July 2023 / Approved: 25 July 2023 / Online: 25 July 2023 (10:42:03 CEST)
Version 3
: Received: 7 August 2023 / Approved: 8 August 2023 / Online: 8 August 2023 (11:09:48 CEST)
Version 4
: Received: 28 August 2023 / Approved: 28 August 2023 / Online: 28 August 2023 (08:27:47 CEST)
How to cite:
Pan, Z.; Xie, C.; Yan, X. T.; Su, Y. M.; Ul Haq, A.; Wang, J. Chemicals in Essential Oils of Lamiophlomis rotata (Benth.) Kudo and Their Antioxidant Activities. Preprints2023, 2023070092. https://doi.org/10.20944/preprints202307.0092.v2
Pan, Z.; Xie, C.; Yan, X. T.; Su, Y. M.; Ul Haq, A.; Wang, J. Chemicals in Essential Oils of Lamiophlomis rotata (Benth.) Kudo and Their Antioxidant Activities. Preprints 2023, 2023070092. https://doi.org/10.20944/preprints202307.0092.v2
Pan, Z.; Xie, C.; Yan, X. T.; Su, Y. M.; Ul Haq, A.; Wang, J. Chemicals in Essential Oils of Lamiophlomis rotata (Benth.) Kudo and Their Antioxidant Activities. Preprints2023, 2023070092. https://doi.org/10.20944/preprints202307.0092.v2
APA Style
Pan, Z., Xie, C., Yan, X. T., Su, Y. M., Ul Haq, A., & Wang, J. (2023). Chemicals in Essential Oils of <em>Lamiophlomis rotata</em> (Benth.) Kudo and Their Antioxidant Activities. Preprints. https://doi.org/10.20944/preprints202307.0092.v2
Chicago/Turabian Style
Pan, Z., Anwar Ul Haq and Jian Wang. 2023 "Chemicals in Essential Oils of <em>Lamiophlomis rotata</em> (Benth.) Kudo and Their Antioxidant Activities" Preprints. https://doi.org/10.20944/preprints202307.0092.v2
Abstract
Due to the low content, very few studies were focused on the essential oils (EOs) of Lamiophlomis rotata (Benth.) Kudo (L. rotata), which has been used to treat rheumatic arthritis and grasserie in China. However, such EOs may have important pharmacological activities such as anti-cancer. To explore the potential of such EOs, we firstly conducted a thoroughly investigation on the chemicals in the EOs and their antioxidant activities (AAs), to the best of our knowledge. Light yellow EOs with fresh and elegant smell were obtained by hydro-distillation with average yield as 0.11% (volume mL/weight g). The crystal was separated from the EO through cryoprecipitation, respectively. Therefore, the EOs, crystals, and EOs removed crystals were studied further. A total of 55 components were qualified and quantified, in which 21 ones were first reported in these EOs. In the EOs, crystals and EOs removed crystals, the main compounds were long-chain fatty acids (LCFAs) and their esters, whereas the crystals presented relatively higher content of LCFAs and the EOs removed crystals presented relatively lower content of LCFAs compared with that of corresponding EOs. The most abundant compound n-hexadecanoic acid (palmitic acid), a kind of LCFAs, presented 47.1-60.8%, 61.3-69.2% and 17.8-44.8%, in the EOs, crystals and EOs removed crystals, respectively. Their AAs of three kinds of EOs, crystals and EOs removed crystals and a chemical marker as n-hexadecanoic acid were evaluated through DPPH (1,1-Diphenyl-2-picrylhydrazy1 radical), ABTS ((2, 2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), and FRAP (ferric reducing/antioxidant power) assays, respectively. Three kinds of EOs and EOs removed crystals presented some AAs, but not so strong compared with that of ascorbic acid. Usually, the EOs removed crystals showed some stronger AAs compared with that of the corresponding EOs. It should be noteworthy that the crystals showed nearly non AAs and even pro-oxidant activities. The palmitic acid (PA) also presented pro-oxidant activities in a concentration dependant manner. It can be deduced that the monounsaturated FAs (MUFAs) including 9E-hexadecenoic acid, palmitoleic acid and oleic acid, and polyunsaturated FAs (PUFAs) only including linoleic acid detected in this study had some AAs. The FAs have important meaning for keeping the balance between oxidant and antioxidant which depends on their unsaturation extent. This study will give some hints for the full usage of such EOs with lower extracted rate and mainly composed of FAs such as PA.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received:
25 July 2023
Commenter:
Jian Wang
Commenter's Conflict of Interests:
Author
Comment:
After fully considering the reviewers’ comment and the continuous working, this article was revised greatly. The revised paper is much more focused on the fatty acids (FAs) which can be classified as long-chain FAs (LCFAs) or short-chain FAs (SCFAs) according to chain length or saturated FAs (SFAs), monounsaturated FAs (MUFAs) and polyunsaturated FAs (PUFAs) according to the unsaturation extent. In further, the relationship between the antioxidant activities (AAs) of essential oils (EOs), separated crystals, EOs removed crystals, and a chemical marker n-hexadecanoic acid, were analyzed in-depth. Some new related literatures were cited as references.In detail, the “unknown-1” in the former paper was ascertained as linalool through carefully checking since the chemical standard linalool showed the similar spectrum at the same condition. As a result, the “unknown-1” in Tables 1, 2, its figure and related content were deleted and the related data were combined to those of linalool. The No. of other unknown compounds and other figures were revised accordingly. In total, 55 compounds were identified and quantified, the corresponding revision was made. Besides, some figures with low-resolution were replaced by those with high-resolution, respectively. The graphical abstract (GA) pictures the main process and findings of this study.
Commenter: Jian Wang
Commenter's Conflict of Interests: Author