Xing-Wei Yang

Hyperuralones A and B, New Acylphloroglucinol Derivatives with Intricately Caged Cores from Hypericum uralum

Hyperuralone A (1), a polycyclic polyprenylated acylphloroglucinol possessing an unprecedented tetracyclo-[5.3.1.1(4,9).0(4,11)]-dodecane core, was characterized from Hypericum uralum together with hyperuralone B (2), a congener with another complex caged skeleton. Their structures were determined by extensive spectroscopic analysis and ECD calculations. A plausible biosynthetic pathway of their intriguing architectures via intramolecular Diels-Alder reactions was also proposed. Compound 1 exhibited obviously cytotoxic activities against five human cancer cell lines in vitro (IC50 4.6-14.4 μM).

Hypersubones A and B, New Polycyclic Acylphloroglucinols with Intriguing Adamantane Type Cores from Hypericum subsessile

Hypersubones A and B (1, 2), two adamantane type polycyclic polyprenylated acylphloroglucinols possessing an unprecedented seco-adamantane architecture and a tetracyclo-[6.3.1.1(3,10).0(4,8)]-tridecane core combined with a peroxide ring, respectively, were isolated from Hypericum subsessile together with three analogues (3-5). Their structures were determined by extensive NMR spectroscopic analysis, ECD calculations, and single-crystal X-ray diffraction. Compound 2 exhibited significant cytotoxicities against four human cancer lines in vitro (IC50 0.07-7.52 μM).

New acylphloroglucinol derivatives with diverse architectures from Hypericum henryi.

Hyphenrones A-F (1-6), six polycyclic polyprenylated acylphloroglucinol derivatives with four architectures including three unprecedented cores as exemplified by 1, 3, and 4, were isolated from Hypericum henryi. Compounds 3 and 4 possess two unique 5/8/5 and 6/6/5/8/5 fused ring systems, respectively. Their absolute configurations were defined by experimental and calculated ECD of 4 and X-ray diffractions of 5 and 6, coupled with their putative biosynthetic origins. Three compounds exhibited interesting AChE inhibitory activities.

Hypercohin A, a new polycyclic polyprenylated acylphloroglucinol possessing an unusual bicyclo[5.3.1]hendecane core from Hypericum cohaerens

Hypercohin A (1), an unprecedented polycyclic polyprenylated acylphloroglucinol featuring with an unusual bicyclo[5.3.1]hendecane core, was isolated from Hypericum cohaerens. Its structure and absolute configurations were elucidated by extensive NMR methods and crystal X-ray diffractions of its p-bromobenzoate ester (2).

Bioactive Polyprenylated Acylphloroglucinol Derivatives from Hypericum cohaerens

Nine new polyprenylated acylphloroglucinol derivatives, hypercohins B-J (1-9), and nine known analogues were isolated from the aerial parts of Hypericum cohaerens. The structures of 1-9 were elucidated based on spectroscopic analysis, and the absolute configuration of 1 was confirmed by X-ray crystallographic analysis. The inhibitory activities of these isolates on acetylcholinesterase and five human tumor cell lines were tested, and hypercohins B-D (1-3) exhibited moderate inhibitory activity (IC₅₀ 5.8-17.9 μM) against the tested tumor cell lines.

Polycyclic Polyprenylated Acylphloroglucinol Congeners Possessing Diverse Structures from Hypericum henryi.

Polycyclic polyprenylated acylphloroglucinols (PPAPs) are a class of hybrid natural products sharing the mevalonate/methylerythritol phosphate and polyketide biosynthetic pathways and showing considerable structural and bioactive diversity. In a systematic phytochemical investigation of Hypericum henryi, 40 PPAP-type derivatives, including the new compounds hyphenrones G-Q, were obtained. These compounds represent 12 different structural types, including four unusual skeletons exemplified by 5, 8, 10, and 17. The 12 different core structures found are explicable in terms of their biosynthetic origin. The structure of a known PPAP, perforatumone, was revised to hyphenrone A (5) by NMR spectroscopic and biomimetic synthesis methods. Several compounds exhibited inhibitory activities against acetylcholinesterase and human tumor cell lines. This study deals with the structural diversity, function, and biogenesis of natural PPAPs.

Hyperjapones A–E, Terpenoid Polymethylated Acylphloroglucinols from Hypericum japonicum

Hyperjapones A-E (1-5), novel terpenoid polymethylated acylphloroglucinols (TPAPs) with unusual architectures, were characterized from Hypericum japonicum. Their structures and absolute configurations were determined by comprehensive spectroscopic data and X-ray diffractions. Compound 1 was obtained as a racemic mixture and was separated by a column coated with cellulose tris(4-methylbenzoate) after attempts with various chiral materials. Compounds 1, 2, and 4 exhibited moderate antitumor activities in vitro.

Indole alkaloids with new skeleton activating neural stem cells.

Alstoscholarisines A-E (1-5), five unprecedented monoterpenoid indole alkaloids with 6/5/6/6/6 fused-bridge rings, were isolated from Alstonia scholaris. They promoted adult neuronal stem cells (NSCs) proliferation significantly, in which the most active one (1) functioned from a concentration of 0.1 μg/mL in a dosage-dependent manner. Furthermore, 1 enhanced NSC sphere formation and neurogenic fate commitment through activation of a Wnt signaling pathway and promoted NSC differentiation but did not affect proliferation of neuroblastoma cells.

Przewalskone: a cytotoxic adduct of a danshenol type terpenoid and an icetexane diterpenoid via hetero-Diels-Alder reaction from Salvia przewalskii.

Przewalskone (1), an unprecedented adduct of two different terpenoid units via a hetero-Diels-Alder cycloaddition, was isolated from the roots of Salvia przewalskii. The structure and absolute configurations were elucidated by extensive analysis of NMR spectra and crystal X-ray diffractions. Compound 1 exhibited significant cytotoxicities against five human cancer lines in vitro (IC(50) 0.69-2.35 μM).

Cytotoxic diterpenoids from Salvia yunnanensis

Forty-six abietane type diterpenoids possessing nine different fused ring systems were characterized from the roots of Salvia yunnanensis, six of which (salyunnanins A-F, 1-6) had different nor-abietane, homo-abietane, seco-abietane, and normal abietane architectures. Their structures were elucidated by comprehensive NMR and MS spectroscopic analyses. The inhibitory activities of these isolates against six human tumor lines were tested in vitro. Several of the compounds exhibited substantial cytotoxicity with IC50 values of 0.86-10.1μM.