Anti-inflammatory bicyclic polyprenylated acylphloroglucinols with diverse architectures including an unprecedented 6/6/6 tricyclic core from Garcinia yunnanensis.

Garciyunnanol A (1), an unprecedented 1,2-seco-bicyclic polyprenylated acylphloroglucinol (BPAP) possessing a unique 6/6/6 tricyclic core, was characterized from Garcinia yunnanensis together with 16 BPAPs, including eight new compounds (garciyunnanols B-I, 2-9). Biogenetically, the bicyclo[3.3.

Structurally diverse ent-clerodanoids from the aerial parts of Isodon scoparius.

Scoparodane C (1), a diterpenoid with a rare 3,4-seco-3-nor-2,11-epoxy-ent-clerodane scaffold, was obtained from the aerial parts of Isodon scoparius, along with isocopariusines A-E (2-6), five ent-clerodanoids featuring a 5/6-fused ring system, and isocopariusines F-H (7-9), three common ent-clerodanoids. The structures of these previously undescribed compounds were established by a combination of spectroscopic analysis, X-ray diffraction, chemical derivatization, and quantum chemical calculation. Remarkably, isocopariusine B (3) showed strong resistance reversal activity against fluconazole-resistant Candida albicans.

Isoxerophilusins A and B, Two Novel Polycyclic Asymmetric Diterpene Dimers from : Structural Elucidation, Modification, and Inhibitory Activities against α-Glucosidase.

Isoxerophilusins A () and B (), two unprecedented diterpene heterodimers biogenetically from -atisanes and abietanes, were isolated from the rhizomes of . Their structures were determined by extensive spectroscopic analysis and single-crystal X-ray diffraction. Selective esterification of generated 11 new derivatives.

Discovery of Natural Potent HMG-CoA Reductase Degraders for Lowering Cholesterol.

Exploitation of key protected wild plant resources makes great sense, but their limited populations become the major barrier. A particular strategy for breaking this barrier was inspired by the exploration of a resource-saving fungal endophyte Penicillium sp. DG23, which inhabits the key protected wild plant Schisandra macrocarpa.

Structurally diverse spirocyclic polycyclic polyprenylated acylphloroglucinols from Hypericum ascyron Linn. and their anti-tumor activity.

Ten spirocyclic polycyclic polyprenylated acylphloroglucinols (PPAP), hunascynols A-J (1-10), and 12 known analogs were isolated from the aerial parts of Hypericum ascyron Linn. Compounds 1 and 2, which share a 1,2-seco-spirocyclic PPAP skeleton, could be derived from spirocyclic PPAP, with a common octahydrospiro[cyclohexan-1,5'-indene]-2,4,6-trione core, through a cascade of Retro-Claisen, keto-enol tautomerism, and esterification reactions. Aldolization of normal spirocyclic PPAP yielded 3, which has a caged framework with a 6/5/6/5/6 ring system.

Cyclobutane-Containing Meroditerpenoids, (+)-Isoscopariusins B and C: Structure Elucidation and Biomimetic Synthesis.

(+)-Isoscopariusins B () and C (), two meroditerpenoids containing a 6/6/4 tricyclic carbon skeleton and seven continuous stereocenters, were identified from . The structures were determined by nuclear magnetic resonance analysis and concise biomimetic syntheses from readily available alkene in seven and six steps, respectively. An intermolecular [2+2] photocycloaddition with cooperative catalysis of a Lewis acid and an Ir photocatalyst was used to construct a cyclobutane core with four stereogenic centers.

Carascynol A, a hybrid of caryophyllane-type terpenoid and a C unit degraded by polyprenylated acylphloroglucinols from Hypericum ascyron.

Carascynol A, an unprecedented 4/9/8 ring system hybrid with a peroxide bridge, was characterized from Hypericum ascyron. The architecture contains a caryophyllane-type moiety and a C unit derived from polyprenylated acylphloroglucinols. Its structure and absolute configuration were determined by comprehensive spectroscopic and X-ray diffraction data.

Isolation and Bioinspired Total Synthesis of Rugosiformisin A, A Skeleton-Rearranged Abietane-Type Diterpenoid from .

Rugosiformisin A, a skeleton-rearranged abietane-type diterpenoid with a spiro[4.5]decane motif, was isolated from . Its structure was unambiguously established via NMR spectroscopic analysis and single-crystal X-ray diffraction.

Scopariusicides D-M, ent-clerodane-based isomeric meroditerpenoids with a cyclobutane-fused γ/δ-lactone core from Isodon scoparius.

Scopariusicides D-M (1-10), ten new ent-clerodane-based meroditerpenoids with a cyclobutane-fused γ/δ-lactone core, were isolated from Isodon scoparius. Their structures were determined by comprehensive analysis of spectroscopic data, single-crystal X-ray diffraction, chemical transformation, and TDDFT ECD calculation. A plausible biosynthetic pathway of 1-10 was proposed in which the asymmetrical cyclobutane ring was formed via a crossed "head-to-tail" intermolecular [2 + 2] cycloaddition in anti/syn facial approaches between an ent-clerodane lactone and a cis-4-hydroxycinnamic acid.

Spiro -Clerodane Dimers: Discovery and Green Approaches for a Scalable Biomimetic Synthesis.

Scospirosins A () and B (), two unprecedented spiro -clerodane dimers with 6/6/10/6 and 6/6/6/6/6 ring systems, respectively, were isolated from . Their structures were unambiguously established by spectroscopic, X-ray crystallographic, and chemical approaches. A bioinspired protecting-group-free strategy for their synthesis was achieved on a gram scale and featured the application of green methods, including neat reaction, sensitized photooxygenation, and electrochemical oxidation.

-Kaurane-Based Diterpenoids, Dimers, and Meroditerpenoids from .

Eight new diterpenoids (-) with varied structures were isolated from the aerial parts of . Among them, xerophilsin A () was found to be an unusual meroditerpenoid representing a hybrid of an kauranoid and a long-chain aliphatic ester, xerophilsins B-D (-) are dimeric -kauranoids, while xerophilsins E-H (-) are new kauranoids. The structures of - were elucidated mainly through the analyses of their spectroscopic data.

Structural determination of eleven new preschisanartane-type schinortriterpenoids from two Schisandra species and structural revision of preschisanartanin J using NMR computation method.

Nineteen preschisanartane-type schinortriterpenoids (SNTs), among which eleven ones were previously undescribed, were isolated from two Schisandra species, S. sphaerandra and S. rubriflora.

Isoscoparins R and S, two new -clerodane diterpenoids from .

Two new -clerodane diterpenoids, named isoscoparins R and S ( and ), were isolated from the aerial parts of . Their structures were characterized mainly by analyzing the NMR and HRESIMS data, and the relative configuration of compound was determined by single-crystal X-ray diffraction. Compound showed weak activity as an autophagic inhibitor.

Secondary Metabolites from the Endophytic Fungus Xylaria sp. hg1009.

A detailed chemical investigation of the secondary metabolites produced by the endophytic fungus Xylaria sp. isolated from the stems of Isodon sculponeatus afforded six new compounds, xylariahgins A-F (1-6), two new natural products (7 and 8), along with two known compounds (9 and 10) (Fig. 1).

Five new schinortriterpenoids from Schisandra propinqua var. propinqua.

Five new schinortriterpenoids, propinqtrilactones A and B (1 and 2) with rare lancischiartane scaffold, and propindilactones V-X (3-5), were isolated from the stems and leaves of Schisandra propinqua var. propinqua. Their structures were elucidated on the basis of comprehensive spectroscopic and mass spectrometric analysis.

7α,20-Epoxy-ent-kaurane Diterpenoids from the Aerial Parts of Isodon pharicus.

A phytochemical investigation of an ethyl acetate extract of the aerial parts of Isodon pharicus led to the isolation of 21 new 7α,20-epoxy-ent-kaurane diterpenoids, pharicins C-W (1-21), and 29 known (22-50) analogues. The structural characterization of 1-21 and assignment of their relative configurations were accomplished by spectroscopic data interpretation, while the structures of 1 and 16 were confirmed by X-ray crystallography. The absolute stereostructure of 1 was confirmed by electronic circular dichroism data analysis.

Gypmacrophin A, a Rare Pentacyclic Sesterterpenoid, Together with Three Depsides, Functioned as New Chemical Evidence for Gypsoplaca macrophylla (Zahlbr.) Timdal Identification.

The phytochemical investigation on 1 g of materials from (Zahlbr.) Timdal resulted in the discovery of gypmacrophin A, a rare pentacyclic sesterterpenoid; brialmontin III, a new polysubstituted depside and two known ones, brialmontins I and II. The structure and absolute configurations of gypmacrophin A were elucidated by spectroscopic analyses and computational methods.

Structurally Diverse Diterpenoids from Isodon scoparius and Their Bioactivity.

Fourteen new diterpenoids (1-14) based on four skeletal types and two known analogues (15 and 16) were isolated from the aerial parts of Isodon scoparius. Compound 2 is the first ent-kaurane diterpenoid featuring a 1,11-ether bridge, and the structures of these new compounds were established mainly by NMR and MS methods. The absolute configurations of 1 and 5 and the relative configuration of 3 were determined using single-crystal X-ray diffraction.

Ent-Abietanoids Isolated from Isodon serra.

Four new -abietane diterpenoids, along with four known ones were isolated from the aerial parts of , a traditional Chinese folk medicine. The new diterpenoids were named as serrin K (), xerophilusin XVII (), and enanderianins Q and R ( and ), while the known ones were identified as rubescansin J (), (3α,14β)-3,18-[(1-methylethane-1,1-diyl)dioxy]--abieta-7,15(17)-diene-14,16-diol (), xerophilusin XIV (), and enanderianin P (), respectively. Their structures were elucidated by extensive spectroscopic analysis and comparison with the literature.

Scopariusicides, Novel Unsymmetrical Cyclobutanes: Structural Elucidation and Concise Synthesis by a Combination of Intermolecular [2 + 2] Cycloaddition and C-H Functionalization.

Scopariusicides A (1) and B (2), two novel immunosuppressive unsymmetrical cyclobutane derivatives, were isolated from the aerial parts of Isodon scoparius. Moreover, based on the results of phytochemical investigation, a concise stereocontrolled synthesis of scopariusicide A and its analogues with enhanced biological activities was efficiently achieved using the main diterpenoid (3) isolated from this plant as a readily available starting material. A crossed intermolecular [2 + 2] photocycloaddition and a Pd-catalyzed sp(3) C-H bond β-arylation were used synergistically to access the highly congested unsymmetrical cyclobutane core with four contiguous stereocenters.