Phenolic compounds from Pamotrema dilatatum growing in Lam Dong province

Abstract

Introduction: Only chemical study on the lichen Parmotrema dilatatum was found so far in the world. The lichen Parmotrema dilatatum widely distributed in Lam Dong province, Vietnam has been studied about the isolation and elucidation of several metabolites.
 Methods: Phytochemical study on the polar fractions of this lichen was carried out by using various chromatographic methods including thin-layer chromatography and normal phase silica gel chromatography.
 Results: Eight phenolic compounds were isolated. The chemical structures of isolated compounds were unambiguously elucidated by NMR spectroscopy and comparison with the data in the literature. These are 8'-O-methylsalazinic acid, salazinic acid, 8'-O-methylprotocetraric acid, diffractaic acid, lecanorin, lecanoric acid, isolecanoric acid, and diorcinolic acid.
 Conclusion: Among them, 8'-O-methylsalazinic acid was found as a new natural product.

α-Glucosidase Inhibitory and Glucose Uptake Stimulatory Effects of Phenolic Compounds FromDendrobium christyanum

“…In this study, chromatographic separation of the MeOH extract of D. christyanum root led to the isolation of 13 compounds which included methyl haematommate (1), 21 neicosyl transferulate (2), 22 methyl 2,4-dihydroxy-3,6-dimethylbenzoa te (3), 23 ndocosyl 4-hydroxy-transcinnamate (4), 24 vanillin (5), 25 coniferyl aldehyde (6), 26 4,5-dihydroxy-2-methoxy-9,10dihydrophenanthrene (7), 27 moscatilin (8), 28 aloifol I (9), 29 gigantol (10), 30 batatasin III (11), 31 dendrosinen B (12), 32 and diorcinolic acid ( 13) 33 (Figure 1). The structures of these isolates were determined by comparing their 1 H NMR, 13 C NMR, and MS data with literature values (see supplemental material).…”

Phenolic compounds from the lichen Parmotrema tinctorum

“…The mass value of compound 6 has 44 more atomic mass units than those of 5, which showed the presence of a carboxyl group. Base on the good compatibility of its HR-ESI-MS and NMR data with those reported in the literature 7,9 , 6 was proposed to be lecanoric acid. Compound 7 was a depside.…”

“…Base on the above HR-ESI-MS analysis as well as 2D NMR data of 5 showed that it could be a depside that was combined by 2 and 1 through an ester bridge (Figure 1). Thus compound 5 was assigned as lecanorin 7,9 . Compound 6 was also a depside with similar NMR signals as those of 5, except for the displaying of carboxyl group at C-1 instead of an aromatic proton in 5.…”

“…for C 24 H 20 O 10 -H 467.0978, therefore 7 was indicated as gyrophoric acid. 9 The inhibitory effect against α-glucosidase of some isolated compounds of P.tinctorum was tested. The results of tested compounds 4 displayed high-potency inhibitors with IC50 values in 38.9 µM, compared with the control acarbose IC50 214.5 µM.…”

Recent advances on natural depsidones: sources, biosynthesis, structure-activity relationship, and bioactivities

“…Chemical investigation guided by HPLC/DAD of the EtOAc extract of the marine-derived Curvularia sp. IFBZ10 resulted in new depsidones; 30 – 35 that were separated by SiO 2 CC/HPLC and their structures and absolute configuration were determined by spectral analyses as well as TDDFT/ECD (time-dependent density functional theory/electronic circular dichroism) and DFT/NMR (density functional theory/nuclear magnetic resonance) calculations ( Duong, 2019 ). The anti-inflammation potential of 30 , 31 , 34 , and 35 was assessed by measuring IL-1β production inhibition in Propionibacterium acnes -induced THP-1 cells.…”