Proceedings of Chemistry, Pharmacology, Pharmacokinetics and Synthesis of Biflavonoids

Biflavonoids, composed of two monoflavonoid residues, occur naturally in angiosperms, bryophytes, ferns, and gymnosperms. More than 592 biflavonoids have been structurally elucidated, and they can be classified into two groups of C-C and C-linear fragments-C, based on whether the linker between the two residues contains an atom. As the linker can be established on two arbitrary rings from different residues, the C-C type contains various subtypes, as does the C-linear fragment-C type. Biflavonoids have a wide range of pharmacological activities, including anti-inflammatory, antioxidant, antibacterial, antiviral, antidiabetic, antitumor, and cytotoxic properties, and they can be applied in Alzheimer's disease and Parkinson's disease. This review mainly summarizes the distribution and chemistry of biflavonoids; additionally, their bioactivities, pharmacokinetics, and synthesis are discussed.

Structural Revision of Garcinielliptin Oxide and Garcinielliptone E

Previously, Lin et al. reported the isolation and structural determination of two triterpenoids, garcinielliptin oxide (GO) and garcinielliptone E (GE). Their unusual structural features, which remained unparalleled in subsequent decades despite the intervening discovery of hundreds of other polycyclic polyprenylated acylphloroglucinols (PPAPs), caused us to question the originally assigned structures, so GO was reisolated from Garcinia subelliptica, and its NMR spectra were reacquired. In this Note, we revise the structures of GO and the related GE via NMR analysis, biosynthetic considerations, and chemical conversion. Garcinielliptone T, a new PPAP, was also isolated and characterized. GO exhibited weak inhibitory activity against acetylcholinesterase with an IC₅₀ value of 20.7 μM.