Cassane diterpenoids with α-glucosidase inhibitory activity from the fruits of Pterolobium macropterum

• Sarot Cheenpracha,
• Ratchanaporn Chokchaisiri,
• Lucksagoon Ganranoo,
• Sareeya Bureekaew,
• Thunwadee Limtharakul and
• Surat Laphookhieo

Beilstein J. Org. Chem. 2023, 19, 658–665, doi:10.3762/bjoc.19.47

• with an α,β-butenolide-type, whereas compound 3 is a dimeric caged cassane diterpenoid with unique 6/6/6/6/6/5/6/6/6 nonacyclic ring system. The structures of 1 and 3 were characterized by extensive spectroscopic analysis combined with computational ECD analyses. The α-glucosidase inhibitory activity

• of isolated compounds was evaluated, and compounds 1 and 3 showed significant α-glucosidase inhibitory activity with IC50 values of 66 and 44 μM. Keywords: α-glucosidase inhibitory activity; cassane diterpenoid; Fabaceae; medicinal plant; Pterolobium macropterum; Introduction Diabetes mellitus is a

• and 6β-cinnamoyl-7β-hydroxyvouacapen-5α-ol, have been reported to exhibit significant α-glucosidase inhibitory activity [5]. The genus Pterolobium, comprising approximately 10 species distributed widely in Africa, China, and Thailand [6], is flowering shrubs belonging to Fabaceae. There are only four

New furoisocoumarins and isocoumarins from the mangrove endophytic fungus Aspergillus sp. 085242

• Ze’en Xiao,
• Senhua Chen,
• Runlin Cai,
• Shao’e Lin,
• Kui Hong and
• Zhigang She

Beilstein J. Org. Chem. 2016, 12, 2077–2085, doi:10.3762/bjoc.12.196

• characterized spectroscopically and isolated from a natural source for the first time. Asperisocoumarins A–D (1–4) related to the class of furo[3,2-h]isocoumarins are rarely occurring in natural sources. Compounds 2, 5, and 6 showed moderate α-glucosidase inhibitory activity with IC50 of 87.8, 52.3, and 95.6 μM

• isopentenyl substituent with two adjacent carbonyl groups seems to be rare in natural isocoumarin derivatives and asperisocoumarin F (6) presents as a scaffold with an ether dimer of isocoumarin. All isolates were evaluated for their α-glucosidase inhibitory activity using clinical acarbose (IC50 of 628.3 μM

• ) as a positive control. Compounds 2, 5, and 6 showed moderate α-glucosidase inhibitory activity with IC50 of 87.8, 52.3, and 95.6 μM, respectively. The other compounds were inactive (> 300 μM). Compounds 1–9 were also evaluated for antibacterial activities against Staphylococcus aureus, Staphylococcus

New depsidones and isoindolinones from the mangrove endophytic fungus Meyerozyma guilliermondii (HZ-Y₂) isolated from the South China Sea

• Senhua Chen,
• Zhaoming Liu,
• Yayue Liu,
• Yongjun Lu,
• Lei He and
• Zhigang She

Beilstein J. Org. Chem. 2015, 11, 1187–1193, doi:10.3762/bjoc.11.133

• exhibited strong α-glucosidase inhibitory activity with IC50 values ranging from 2.1 to 13.3 μM. Moreover, kinetic studies of compounds 2 and 6 showed that both of them were noncompetitive inhibitors of α-glucosidase. Keywords: endophytic fungus; depsidone; α-glucosidase inhibitory activity; isoindolinone

• [13][14][15][16][17]. Recently, a chemical investigation of the endophytic fungal strain Meyerozyma guilliermondii (HZ-Y2), obtained from the roots of the mangrove plant Kandelia obovata, was carried out. The EtOAc extract of a fermentation broth of the fungus showed α-glucosidase inhibitory activity

• ). In the bioactivity assay, all depsidones showed strong α-glucosidase inhibitory activity with IC50 values ranging from 2.1 to 13.3 μM. Details of the isolation, structure elucidation, and biological activity of these compounds are reported herein. Results and Discussion Botryorhodine E (1) was