α-Glucosidase Inhibitory and Antimicrobial Benzoylphloroglucinols from Garcinia schomburgakiana Fruits: In Vitro and In Silico Studies

Abstract

α-Glucosidase plays a role in hydrolyzing complex carbohydrates into glucose, which is easily absorbed, causing postprandial hyperglycemia. Inhibition of α-glucosidase is therefore an ideal approach to preventing this condition. A novel polyprenylated benzoylphloroglucinol, which we named schomburgkianone I (1), was isolated from the fruit of Garcinia schomburgkiana, along with an already-reported compound, guttiferone K (2). The structures of the two compounds were determined using NMR and HRESIMS analysis, and comparisons were made with previous studies. Compounds 1 and 2 exhibited potent α-glucosidase inhibition (IC50s of 21.2 and 34.8 µM, respectively), outperforming the acarbose positive control. Compound 1 produced wide zones of inhibition against Staphylococcus aureus and Enterococcus faecium (of 21 and 20 mm, respectively), compared with the 19 and 20 mm zones of compound 2, at a concentration of 50 µg/mL. The MIC value of compound 1 against S. aureus was 13.32 µM. An in silico molecular docking model suggested that both compounds are potent inhibitors of enzyme α-glucosidase and are therefore leading candidates as therapies for diabetes mellitus.

Constituents of the Stem Bark of Symphonia globulifera Linn. f. with Antileishmanial and Antibacterial Activities

“…The duplication of all these data in association with the mass data confirmed that 2/3 was a mixture of two polyisoprenylated benzophenone derivatives. The 13 C NMR spectrum of 2/3 displayed characteristic signals for a bicyclo[3.3.1]nonane ring as pairs of carbons at ẟ C 170.3/170.5 (C-1), 125.6/125.9 (C-2), 193.3/193.6 (C-3), 68.9/69.0 (C-4), 48.3/48.4 (C-5), 2×39.4 (C-6), 38.1/38.3 (C-7), 51.2/51.5 (C-8), and 206.2/206.3 (C-9) [ 37 , 39 ].…”

“…In addition, the combination of the DEPT 135 and HSQC confirmed the presence of seven isopent-2-enyl units, one isopent-3-enyl with the characteristic signals at δ C /δ H [22.4/1.94 (C-39/H-39), 35.4/1.21 (C-40/H-40), 145.0 (C-41), 21.5/1.74 (C-42/H-42), and 110.4/4.79 (C-43/H-43)], and one dimethylpyrane moiety identified by the signals at δ C /δ H {[28.3/0.89 (C-29/H-29), 41.8/1.10 (C-30/H-30), 86.2 (C-31), 27.9/0.89 (C-32/H-32), 20.6/1.27 (C-33/H-33), 2 ], [28.3/0.94 (C-29/H-29), 42.9/1.10 (C-30/H-30, 86.5 (C-31), 28.0/0.89 (C-32/H-32), 20.7/1.29 (C-33/H-33), 3 ]}. All these data indicated that the structures of 2/3 are closely related to shomburgkianone I [ 39 ]. The location of the dimethylpyrane moiety on the bicyclo unit was deduced by the HMBC correlation of H-29 (ẟ H 3.00/3.05)/C-8 (ẟ C 51.2/51.5), C-1 (δ C 170.3/170.5), C-30 (δ C 41.8/42.9), and C-31 (δ C 86.5).…”

In vitro anti-inflammatory, in silico molecular docking and molecular dynamics simulation of oleanane-type triterpenes from aerial parts of Mussaenda recurvata

“…The validation of the model was based on the values of RMSD bet ranked pose and reference pose, one small ligand that is available in the target enzyme, . 39,40…”

“…The validation of the model was based on the values of RMSD bet ranked pose and reference pose, one small ligand that is available in the target enzyme, 4WCU. 39,40 3.6. Molecular dynamics simulation A top-docked pose with high binding energy was used in an MD simulation employing the GROMACS soware program 41 with the GROMOS9643a1 force eld to ensure conformational stability.…”

Bio-guided isolation of alpha-glucosidase inhibitory compounds from Vietnamese Garcinia schomburgkiana fruits: in vitro and in silico studies

“…To date, there have been two reports on the phytochemical constituents of G. schomburgkiana fruits, uncovering 14 phloroglucinols and xanthones. 8,10 In 2016, Le and co-workers reported the presence of 12 new phloroglucinols, showing strong cytotoxicity against several cancer cell lines. 8 In 2021, Nguyen and co-workers reported two potent alpha-glucosidase inhibitors, namely schomburgkianone I and guttiferone K, isolated from Thai fruits.…”