New meta -depsidones and diphenyl ethers from the lichen Parmotrema tsavoense (Krog &amp; Swinscow) Krog &amp; Swinscow, Parmeliaceae

Duong, Thuc‐Huy; Chavasiri, Warinthorn; Boustié, Joël; Nguyen, Kim‐Phi‐Phung

doi:10.1016/j.tet.2015.06.107

Cited by 43 publications

(35 citation statements)

References 30 publications

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“…Indeed, 5 could be obtained from 6 via a transesterification prior to its dehydration. Such reactions were already reported to occur in lichens (Duong et al, 2015).…”

Section: Resultssupporting

confidence: 57%

New erythritol derivatives from the fertile form of Roccella montagnei

Duong¹,

Huynh²,

Chavasiri

et al. 2017

Phytochemistry

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Chemical investigation of the methanol extract of the fertile form of Roccella montagnei collected in Vietnam afforded twelve secondary metabolites, including five new montagnetol derivatives, orsellinylmontagnetols A-D and a furanyl derivative together with seven known compounds. Their chemical structures were elucidated by analysis of 1D and 2D NMR and high resolution mass spectroscopic data. The relative stereochemistry of two chiral centers (C-2 and C-3) of orsellinylmontagnetols A and B was elucidated by comparison of their coupling constants and the specific rotation with those reported in the literature while the absolute stereochemistry was determined by the application of a modified Mosher method for the hydroxy group at C-3. The absolute configuration (2R,3S) of the butanetetraol moiety of these compounds is in accordance with that of erythrin, a recognized chemotaxonomic marker of the genus Roccella. Five of these compounds were evaluated for their cytotoxic activities against four cancer cell lines. Only orsellinylmontagnetol A exerted a moderate activity against MCF-7 cell line with an IC value of 68.39 ± 3.46 μM.

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“…Indeed, 5 could be obtained from 6 via a transesterification prior to its dehydration. Such reactions were already reported to occur in lichens (Duong et al, 2015).…”

Section: Resultssupporting

confidence: 57%

New erythritol derivatives from the fertile form of Roccella montagnei

Duong¹,

Huynh²,

Chavasiri

et al. 2017

Phytochemistry

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“…Natural content of depsidones was investigated by Duong et al . () in P. tsavoense . Sensitivity of Parmotrema species to UV‐B radiation and changes in secondary metabolites in response to altered UV‐B is still unknown.…”

Section: Introductionmentioning

confidence: 95%

“…Similarly, Armaleo et al (2008) focused on light intensity effects on depsides and depsidones in P. hypotropum. Natural content of depsidones was investigated by Duong et al (2015) in P. tsavoense. Sensitivity of Parmotrema species to UV-B radiation and changes in secondary metabolites in response to altered UV-B is still unknown.…”

Section: Introductionmentioning

confidence: 99%

Effect of UV‐B radiation on the content of UV‐B absorbing compounds and photosynthetic parameters in Parmotrema austrosinense from two contrasting habitats

et al. 2018

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We studied the resistance of Parmotrema austrosinense to UV-B stress. We focused on the effects of a high dose UV-B radiation on the content of chlorophylls, carotenoids and UV-B screening compounds. Photosynthetic parameters were measured by chlorophyll fluorescence (potential and effective quantum yields, photochemical and non-photochemical quenching) and evaluated in control and UV-B-treated lichens. Lichens from two different locations in Cordoba, Argentina, were selected: (i) high altitude and dry plots at (Los Gigantes) and (ii) lowland high salinity plots (Salinas Grandes). UV-B treatment led to a decrease in the content of photosynthetic pigments and UV-B screens (absorbance decrease in 220-350 nm) in the samples from Salinas Grandes, while in Los Gigantes samples, an increase in UV-B screen content was observed. Chlorophyll fluorescence parameters showed a UV-B-induced decline in F /F , Φ and qP indicating limitation of primary photosynthetic processes in photosystem II (PSII) of symbiotic alga, more pronounced in Salinas Grandes samples. Protective mechanism of PSII were activated by the UV-B treatment to a higher extent in samples from Salinas Grandes (NPQ 0.48) than in Los Gigantes samples (NPQ 0.26). We concluded that site-related characteristics, and in particular different UV-B radiation regimen, had a strong effect on resistance of the photosynthetic apparatus of P. austrosinense to UV-B radiation.

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“…The phytochemical investigation of some Vietnamese lichens such as Parmotrema tsavoense, P. praesorediosum, P. tinctorum, Ramalina farinacea, Lobaria orientalis and Roccella montagnei led to the isolation of several new compounds, some of them generally exhibited moderate activity against cancer cell lines. [9][10][11][12][13][14] In this paper, as a part of our searching cytotoxic compounds from Vietnamese lichens, we focused on species Usnea undulata Stirt. which distributed widely in Lam Dong province.…”

Section: Introductionmentioning

confidence: 99%

Investigation of chemical constituents and cytotoxic activity of the lichen Usnea undulata

Tram

Anh

Thuc

et al. 2020

Vietnam Journal of Chemistry

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Lichens are a promising source of good anticancer agents. However the study on their bioactivities remains limited, especially in Vietnam. In this study, three extracts of lichen Usnea undulata Stirt. including n‐hexane, acetone and methanol were investigated for their cytotoxic activity on two human cancer cell lines (MCF‐7, NCI‐H460) and normal fibroblasts by sulforhodamine B (SRB) assay. The results showed that the n‐hexane extract exhibited the highest inhibition activity with IC50 5.26±0.13 μg/mL for MCF‐7 and 6.83±0.64 μg/mL for NCI‐H460, followed by acetone extract with IC50 66.44±1.37 μg/mL and 92.14±1.49 μg/mL, respectively. The methanol extract possessed weak cytotoxic effect against MCF‐7 and NCI‐H460 (IC50 values more than 100 μg/mL). The n‐hexane extract demonstrated interesting activity particularly on MCF‐7 as good selectivity index was recorded (SI > 3). The phytochemical study on n‐hexane and acetone extracts led to the isolation of four compounds including usnic acid (1), methyl orsellinate (2), methyl β‐orsellinate (3), 7‐hydroxyl‐5‐methoxy‐6‐methylphtalide (4) in which compound (4) was isolated the first time in such species. Their structures were elucidated by NMR analysis and compared with literature data.

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New meta -depsidones and diphenyl ethers from the lichen Parmotrema tsavoense (Krog & Swinscow) Krog & Swinscow, Parmeliaceae

Cited by 43 publications

References 30 publications

New erythritol derivatives from the fertile form of Roccella montagnei

New erythritol derivatives from the fertile form of Roccella montagnei

Effect of UV‐B radiation on the content of UV‐B absorbing compounds and photosynthetic parameters in Parmotrema austrosinense from two contrasting habitats

Investigation of chemical constituents and cytotoxic activity of the lichen Usnea undulata

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