α-Glucosidase Inhibitory Depsidones from the Lichen Parmotrema tsavoense

Planta Medica ◽  
2020 ◽  
Vol 86 (11) ◽  
pp. 776-781 ◽  
Author(s):  
Thuc-Huy Duong ◽  
Tai-Xuan-Hoa Hang ◽  
Pierre Le Pogam ◽  
Thanh-Nha Tran ◽  
Dinh-Hung Mac ◽  
...  

AbstractChemical investigation of the lichen Parmotrema tsavoense led to the isolation of 5 new depsidones, parmosidones F – J (1 – 5). These compounds were structurally elucidated using spectroscopic methods including HRESIMS and 2D NMR data. Compounds 1, 3, and 4 were evaluated for their inhibition of α-glucosidase. All exhibited potent α-glucosidase inhibitory activity with IC50 values ranging from 10.7 to 17.6 µM, which was much lower than that of the positive control acarbose (IC50 449 µM).

Author(s):  
Thuy Thi Le Nguyen ◽  
Thuy Thi Pham ◽  
Poul Erik Hansen ◽  
Phung Kim Phi Nguyen

Introduction: Lumnitzera littorea grown at CanGio Mangrove Forest has been investigated. The present study reports the isolation, characterization and evaluation of the alpha-glucosidase inhibitory activity of isolated compounds from Lumnitzera littorea leaves. Methods: Their structures were elucidated by spectroscopic methods (including MS, 1D and 2D–NMR) and comparison with values from the literature. From the n-hexane extract, nine compounds including lupeol (1), betulin (2), betulinic acid (3), oleanolic acid (4), corosolic acid (5), -sitosterol (6), beta-sitosterol 3-O- beta-D-glucopyranoside (7), stigmast-5-ene-3beta-O-(6-O-hexadecanoyl-beta-D-glucopyranoside) (8), and stigmast-4-ene-3-one (9) were isolated and identified. Results: The results of the alpha-glucosidase inhibitory activity showed thatcorosolic acid (5) and oleanolic acid (4) were the most potent, with IC50 values of 17.86 +/- 0.42 and 18.82 +/- 0.59 ug/mL, respectively. Five of the other seven compounds exhibited inhibitory activity with IC50 values below 100 ug/mL, and higher than the positive control acarbose (127.64 +/- 0.64 ug/mL).  


Marine Drugs ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. 714
Author(s):  
Fei Cao ◽  
Li Pan ◽  
Wen-Bin Gao ◽  
Yun-Feng Liu ◽  
Cai-Juan Zheng ◽  
...  

From the marine-derived fungus Penicillium sumatrense (Trichocomaceae), a pair of enantiomers [(+)-1 and (−)-1] were isolated with identical 1D NMR data to drazepinone, which was originally reported to have a trisubstituted naphthofuroazepinone skeleton. In this study, we confirmed the structures of the two enantiomers as drazepinone and revised their structures by detailed analysis of extensive 2D NMR data and a comparison of the calculated 13C chemical shifts, ECD, VCD, and ORD spectra with those of the experiment ones. (+)-1 and (−)-1 were evaluated for their PTP inhibitory activity in vitro. (−)-1 showed selective PTP inhibitory activity against PTP1B and TCPTP with IC50 values of 1.56 and 12.5 μg/mL, respectively.


2018 ◽  
Vol 17 (3) ◽  
pp. 134-139
Author(s):  
R.M. Perez-Gutierrez

Methanol extract from Lippia graveolens (Mexican oregano) was studied in order to identify inhibitory bioactives for protein tyrosine phosphatase 1B (PTP1B). Known flavone as lutein (1), and another flavone glycoside such as lutein-7-o-glucoside (2), 6-hydroxy-lutein-7-ohexoside (3) and lutein-7-o-ramnoide (4) were isolated from methanol extract of aerial parts of the Lippia graveolens. All isolates were identified based on extensive spectroscopic data analysis, including UV, IR, NMR, MS and compared with spectroscopic data previously reported. These flavones were evaluated for PTP1B inhibitory activity. Among them, compounds 1 and 3 displayed potential inhibitory activity against PTP1B with IC50 values of 7.01 ± 1.25 μg/ml and 18.4 μg/ml, respectively. In addition, compound 2 and 4 showed moderate inhibitory activity with an IC50 value of 23.8 ± 6.21 and 67.8 ± 5.80 μg/ml respectively. Among the four compounds, luteolin was found to be the most potent PTP1B inhibitor compared to the positive control ursolic acid, with an IC50 value of 8.12 ± 1.06 μg/ml. These results indicate that flavonoids constituents contained in Lippia graveolens can be considered as a natural source for the treatment of type 2 diabetes.


Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 305
Author(s):  
Guangyuan Luo ◽  
Li Zheng ◽  
Qilin Wu ◽  
Senhua Chen ◽  
Jing Li ◽  
...  

Six new fusarin derivatives, fusarins G–L (1–6), together with five known compounds (5–11) were isolated from the marine-derived fungus Fusarium solani 7227. The structures of the new compounds were elucidated by means of comprehensive spectroscopic methods (1D and 2D NMR, HRESIMS, ECD, and ORC) and X-ray crystallography. Compounds 5–11 exhibited potent anti-inflammatory activity by inhibiting the production of NO in RAW264.7 cells activated by lipopolysaccharide, with IC50 values ranging from 3.6 to 32.2 μM. The structure–activity relationships of the fusarins are discussed herein.


Planta Medica ◽  
2021 ◽  
Author(s):  
Birgit Waltenberger ◽  
Françoise Lohézic-Le Dévéhat ◽  
Thi Huyen Vu ◽  
Olivier Delalande ◽  
Claudia Lalli ◽  
...  

AbstractProtein tyrosine phosphatase 1B plays a significant role in type 2 diabetes mellitus and other diseases and is therefore considered a new drug target. Within this study, an acetone extract from the lichen Stereocaulon evolutum was identified to possess strong protein tyrosine phosphatase 1B inhibition in a cell-free assay (IC50 of 11.8 µg/mL). Fractionation of this bioactive extract led to the isolation of seven known molecules belonging to the depsidones and the related diphenylethers and one new natural product, i.e., 3-butyl-3,7-dihydroxy-5-methoxy-1(3H)-isobenzofurane. The isolated compounds were evaluated for their inhibition of protein tyrosine phosphatase 1B. Two depsidones, lobaric acid and norlobaric acid, and the diphenylether anhydrosakisacaulon A potently inhibited protein tyrosine phosphatase 1B with IC50 values of 12.9, 15.1, and 16.1 µM, respectively, which is in the range of the protein tyrosine phosphatase 1B inhibitory activity of the positive control ursolic acid (IC50 of 14.4 µM). Molecular simulations performed on the eight compounds showed that i) a contact between the molecule and the four main regions of the protein is required for inhibitory activity, ii) the relative rigidity of the depsidones lobaric acid and norlobaric acid and the reactivity related to hydrogen bond donors or acceptors, which interact with protein tyrosine phosphatase 1B key amino acids, are involved in the bioactivity on protein tyrosine phosphatase 1B, iii) the cycle opening observed for diphenylethers decreased the inhibition, except for anhydrosakisacaulon A where its double bond on C-8 offsets this loss of activity, iv) the function present at C-8 is a determinant for the inhibitory effect on protein tyrosine phosphatase 1B, and v) the more hydrogen bonds with Arg221 there are, the more anchorage is favored.


2021 ◽  
Vol 63 (4) ◽  
pp. 42-46
Author(s):  
Thi-My-Linh Lam ◽  
◽  
Minh-Tuan Le ◽  
Manh-Ha Bui ◽  
◽  
...  

A study on the α-glucosidase inhibitory activity of 40 kinds of vegetables, tubers, and fruits found in the An Giang province was conducted. The results indicated that all 40 extracted samples displayed α-glucosidase inhibitory activity at a concentration of 250 μg ml-1, 36 extracted samples showed an inhibition rate greater than 50% at 250 μg ml-1, 25 extracted samples had over 50% at 100 μg ml-1, 17 extracted samples possessed more than 50% at 50 μg ml-1, 7 extracted samples sampled showed over 50% at 25 μg ml-1, 5 extracted samples were greater than 50% at 10 μg ml-1, and 1 extracted sample was greater than 50% at 1 μg ml-1. Among the 40 samples, those taken from the seeds of Areca catechu, the fruits of Cassia grandis, the fruits of Syzygium cumini, the seeds of Glycine max,andthe stems of Enydra fluctuansexhibited the strongest α-glucosidase inhibitory activity in methanol, with IC50 values of 0.15, 2.54, 4.05, 5.17 and 8.68 μg ml-1, respectively, which were stronger than the positive control acarbose with an IC50 value of 214.5 μg ml-1


Author(s):  
Byeonung-Kyu Choi ◽  
Shin-Young Park ◽  
Song-Hee Jo ◽  
Dong-Kug Choi ◽  
Phan Thi Hoai Trinh ◽  
...  

A new compound containing a triene, a tetrahydropyran ring and glycine ester functionalities, restricticin B (1), together with four known compounds (2-5) were obtained from the EtOAc extract of the marine fungus Penicillium janthinellum. The planar structure of 1 was determined by detailed analyses of MS, 1D and 2D NMR data. The relative and absolute configurations of 1 were established via analyses of NOESY spectroscopy data, comparison of optical rotation values with those of restricticin derivatives reported and electronic circular dichroism (ECD). All the compounds were screened for their anti-neuroinflammatory effects in lipopolysaccharide (LPS)-induced BV-2 microglia cells. Restricticin B (1) and N-acetyl restricticin (2) exhibited anti-neuroinflammatory effects by suppressing the production of pro-inflammatory mediators in activated microglial cells.


Planta Medica ◽  
2021 ◽  
Author(s):  
Julianna Max ◽  
Jörg Heilmann

Abstract 1H NMR-guided fractionation of the petroleum ether extract of the aerial parts from Hypericum hirsutum yielded to the isolation of 19 polyprenylated polycyclic acylphloroglucinols. Structure elucidation based on 1D and 2D NMR spectroscopy together with high-resolution electrospray ionization mass spectroscopy revealed 14 acylphloroglucinols with a homoadamantane scaffold (1–14), while 5 further compounds showed an adamantane skeleton (15–19). Except for hookerione C (15), all isolated metabolites are hitherto unknown. While structurally-related metabolites have been isolated from other Hypericum species, it is the first report of admantan and homoadamantan type acylphloroglucinols in section Taeniocarpium Jaub. & Spach (Hypericaceae). The isolated compounds have been tested in a crystal violet-based in vitro assay on their properties to reduce the proliferation of human microvascular endothelial cells compared to hyperforin as the positive control. They showed a moderate reduction of proliferation with IC50 values in the range ~ 3 – 22 µM, with the homoadamantane-based compounds 2 and 4 being the most active. In addition, inhibition of the TNF-α-induced ICAM-1 expression was determined for 1 – 5, 7, and 10 – 12. Substances 3 and 12 reduced the ICAM-1 expression significantly (to 46.7% of control for 3, 62.3% for 12, at 50 µM).


Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2577 ◽  
Author(s):  
Hongjing Dong ◽  
Yanling Geng ◽  
Xueyong Wang ◽  
Xiangyun Song ◽  
Xiao Wang ◽  
...  

One new monoterpene glycoside (1), one new phenyl glycoside (2), one new caffeoyl derivative (3), were isolated from Scindapsus officinalis (Roxb.) Schott., along with four known compounds (4–7). Structures of the isolated compounds were elucidated by extensive analysis of spectroscopic data, especially 2D NMR data and comparison with literatures. All isolates were evaluated for anti-inflammatory activity against nitric oxide (NO) production in vitro. Compounds 3 and 7 exhibited moderate inhibitory effects on NO production with IC50 values of 12.2 ± 0.8 and 18.9 ± 0.3 μM, respectively.


2010 ◽  
Vol 63 (11) ◽  
pp. 1550 ◽  
Author(s):  
Nawong Boonnak ◽  
Achjana Khamthip ◽  
Chatchanok Karalai ◽  
Suchada Chantrapromma ◽  
Chanita Ponglimanont ◽  
...  

Three new xanthones, pruniflorone M-O (1–3), and a new xanthonolignoid, 3-methoxy-5′-demethoxycadensin G (4), were isolated from the green fruits of Cratoxylum formosum ssp. pruniflorum along with three known xanthones (5–7) and a known flavonoid (8). Their structures were elucidated by spectroscopic methods and the structure of 1 was also determined by X-ray crystallography. Compounds 2 and 7 showed potent nitric oxide inhibitory activity with IC50 values of 4.4 and 4.3 μM, respectively. Moreover, 7 also showed strong antibacterial activity against both Gram-positive and Gram-negative bacteria with an MIC value of 4.67 μg mL–1.


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