Japonins A-D, cyathane diterpenoids with neurite outgrowth-promoting activity isolated from Onychium japonicum using NMR and MS/MS-based molecular networking.

Guided by MS/MS-based molecular networking strategy, four new cyathane diterpenoids japonin A-D (1-4), together with the known analogues (5 and 6), have been isolated from aerial parts of Onychium japonicum. The structures of the new compounds were elucidated through a combination of NMR and MS experiments. Through single-crystal X-ray diffraction analysis, and comparison of experimental and calculated computational electronic circular dichroism (ECD) spectra, the absolute configurations of compounds 1-4 were determined. The new compound 1 showed promoting effects on the differentiation of PC12 at a concentration of 40 µM.

Triterpenoid saponins and C21 steroidal glycosides from Gymnema tingens and their glucose uptake activities.

Four new triterpenoid saponins, tigensides A-D (1-4), and one new C21 steroid, tipregnane A(9), together with six known compounds were isolated from the EtOAc fraction of the roots and stems of Gymnema tingens. The chemical structures of the new compounds were determined based on their spectroscopic data, including IR, UV, NMR, and mass spectrometric analysis. All compounds were isolated for the first time. Compounds 1-11 promoted glucose uptake in the range of 1.12 to 2.52 fold, respectively. Compound 2 showed the most potent glucose uptake, with 2.52 fold enhancement. Additionally, compound 2 showed a medium effect on the GLUT4 translocation activity in L6 cells in further study.

Correction: Liu et al. Identification of C21 Steroidal Glycosides from Gymnema sylvestre (Retz.) and Evaluation of Their Glucose Uptake Activities. Molecules 2021, 26, 6549.

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A pair of new isocoumarin enantiomers of Ludwigia hyssopifolia.

A pair of new isocoumarin derivative enantiomers, (S)-(-)-3-(3,3-dichloro-2-hydroxy-propyl)-4-chlorine-6,8-dihydroxy-isochromen-1- one (1a) and (R)-(+)-3-(3,3-dichloro-2-hydroxy-propyl)-4-chlorine-6,8-dihydroxy-isochromen-1- one (1 b), as well as seven known compounds (2-8) were isolated from Ludwigia hyssopifolia. Compounds 1a and 1 b were confirmed to be a pair of enantiomers by chiral HPLC-CD analysis, and the structure of compound 1 was determined by spectroscopic analyses including extensive 1 D (1H NMR, 13C NMR) and 2 D NMR spectra (COSY, HSQC and HMBC) and MS data. And the absolute configurations of compounds 1a and 1 b were determined by the quantum chemical ECD calculations. Compounds 2-8 are firstly reported from this plant. In the in vitro assays, compounds 5 and 8 can inhibit human laryngeal cancer Hep-2 cell line growth in a dose- and time-dependent manner. In addition, compounds 2 and 4 have effects on increasing glucose uptake in vitro. Compound 2 showed a strong glucose uptake in L6 cells, with enhancements by 1.8 folds.

Identification of C21 Steroidal Glycosides from Gymnema sylvestre (Retz.) and Evaluation of Their Glucose Uptake Activities.

Gymnema sylvestre (Retz.) Schult is a multi-purpose traditional medicine that has long been used for the treatment of various diseases. To discover the potential bioactive composition of G. sylvestre, a chemical investigation was thus performed. In this research, four new C21 steroidal glycosides sylvepregosides A-D (1-4) were isolated along with four known compounds, gymnepregoside H (5), deacetylkidjoladinin (6), gymnepregoside G (7) and gymnepregoside I (8), from the ethyl acetate fraction of G. sylvestre. The structures of the new compounds were established by extensive 1D and 2D nuclear magnetic resonance (NMR) spectra with mass spectroscopy data. Compounds 1-6 promoted glucose uptake by the range of 1.10- to 2.37-fold, respectively. Compound 1 showed the most potent glucose uptake, with 1.37-fold enhancement. Further study showed that compounds 1 and 5 could promote GLUT-4 fusion with the plasma membrane in L6 cells. The result attained in this study indicated that the separation and characterization of these compounds play an important role in the research and development of new anti-diabetic drugs and pharmaceutical industry.

2H-pyranone and isocoumarin derivatives from the endophytic fungus Pestalotiopsis microspora SC3082 derived from Scaevola taccada (Gaertn.) Roxb.

Two new 2H-pyranones (1 and 2), two new isocoumarins (4 and 5), and two known compounds (3 and 6) were obtained from solid cultures of the endophytic fungus Pestalotiopsis microspora SC3082. Their structures and revision of the absolute stereochemistry of 6 were established by spectroscopic analyses and computational calculations. Compounds 2, 4 and 6 displayed moderate antifungal activities against Candida albicans ATCC 10321 with MIC values of 25.0, 25.0, and 12.5 µg/mL, respectively.

Ganocapenoids A-D: Four new aromatic meroterpenoids from Ganoderma capense.

Four new aromatic meroterpenoids, ganocapenoids A-D (1-4), together with twelve known analogues (5-16) were isolated from the fruiting bodies of Ganoderma capense. The structures of new compounds were determined through spectroscopic methods including 1D and 2D NMR and MS analyses. Their absolute configurations were assigned by ECD calculations and specific rotation comparison. The biological activities of these substances toward regulation of lipid metabolism, neurite outgrowth-promoting activity, and AchE inhibition were assessed. Compound 15 was found to be able to block lipid accumulation at a concentration of 20 µM, and compounds 4a, 4b, and 11 show moderate neurite outgrowth-promoting activity at 10 µM, while compounds 3, 6, 11, and 13 exhibit potent AchE inhibition with the IC50 values of 28.6 ±â€¯1.9, 18.7 ±â€¯1.6, 8.2 ±â€¯0.2, 26.0 ±â€¯2.9 µM, respectively.

Asperimides A-D, anti-inflammatory aromatic butenolides from a tropical endophytic fungus Aspergillus terreus.

Four new aromatic butenolides, asperimides A-D (1-4), together with a known analogue, butyrolactone I (5), were isolated from solid cultures of a tropical endophytic fungus Aspergillus terreus. The structures of these compounds were elucidated on the basis of spectroscopic methods and electronic circular dichroism calculations. Compounds 1-4 represent the first examples of butenolides with a maleimide core isolated from Aspergillus sp. Inhibitory effects of the isolated compounds on nitric oxide production were investigated in lipopolysaccaride (LPS)-mediated RAW 264.7 cells. Compounds 3 and 4 exhibited potent anti-inflammatory with IC50 values of 0.78 ±â€¯0.06 and 1.26 ±â€¯0.11 µM, respectively.

[Chemical constituents of ethyl acetate fraction of Tetrastigma planicaule].

OBJECTIVE: To investigate the chemical constituents of ethyl acetate of Tetrastigma planicaule. METHODS: The ethyl acetate fraction was isolated and purified by repeated silica gel chromatography and recrystallization. The structures of compounds were identified by physical-chemical methods and spectral data such as MS, 1H-NMR, 13C-NMR, etc. RESULTS: Six compounds were identified as gheddic acid (I), tricosanol (II), beta-sitosterol (III), palmitic acid (IV), ethyl gallate (V) and vanillin (VI), respectively. CONCLUSION: Compounds I, II, V and VI are isolated from this plant for the first time.