A new megastimane sesquiterpenoid from the leaves of Cinnamomum cassia.

A new megastimane sesquiterpenoid, cassianol A (1), and five known analogues (2-6) were isolated from the leaves extract of Cinnamomum cassia. Their structures were elucidated by extensive spectroscopic methods and single-crystal X-ray diffraction analyses. All the isolates were isolated from C. cassia for the first time. The anti-inflammatory activities of compounds 1-6 were evaluated against nitric oxide (NO) production in LPS-induced RAW 264.7 mouse macrophages.

A new pair of cytotoxic enantiomeric isoprenylated chromone derivatives from Pestalotiopsis sp.

A new pair of enantiomeric isoprenylated chromone derivatives, (±)-pestaloficiol X [(±)-1], along with a known compound pestaloficiol J (2), were isolated from the plant endophytic fungus Pestalotiopsis sp. The racemic mixture 1 was separated through chiral HPLC. The structures of new compounds (±)-1 were elucidated on the basis of extensive spectroscopic data and their absolute configurations were further configured through computational analysis of their electronic circular dichroism (ECD) spectra. Compound (+)-1 showed significant inhibitory potency against HL-60 and HEP-3B cell lines, with IC50 values of 1.35 ± 0.15 and 3.70 ± 0.33 µM, respectively, while compound (-)-1 showed significant inhibitory potency against HL-60 and HEP-3B cell lines, with IC50 values of 2.39 ± 0.26 and 2.99 ± 0.35 µM, respectively.

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. Twenty-five of the diterpenoids were screened for their cytotoxic activities against a panel of tumor cell lines, including HL-60, SMMC-7721, A-549, MCF-7, and SW-480. Compounds 11, 16, 38, and 48 exhibited inhibitory activities against these tumor cell lines with IC50 values ranging from 1.01 to 9.62 µM, while 2, 15, 29, and 47 exhibited moderate cytotoxic potency.

Rearranged 6/6/5/6-Fused Triterpenoid Acids from the Stems of Kadsura coccinea.

Fourteen new rearranged 6/6/5/6-fused triterpenoid acids, namely, kadcoccine acids A-N (1-14), were isolated from an EtOAc-soluble extract of the stems of Kadsura coccinea. Their structures were characterized mainly by analyzing 1D and 2D NMR and HRESIMS data and were shown to feature a rare 14(13→12)-abeo-lanostane skeleton. Compounds 7 and 8 represented the first examples of a 5-substituted 2(5H)-furanone motif on the C-17 side chain of this skeleton. The absolute configurations of C-23 for compounds 1, 7, and 8 were determined by comparison of their experimental electronic circular dichroism spectra. All the isolates were screened for their in vitro cytotoxicity against six human tumor cell lines (HL-60, SMMC-7721, A-549, MCF-7, SW-480, and HeLa), and compounds 2 and 8 exhibited weak inhibitory effects with IC50 values ranging from 3.11 to 7.77 µM.

Kadcoccinic Acids A-J, Triterpene Acids from Kadsura coccinea.

Eleven triterpene acids including 10 new compounds (kadcoccinic acids A-J, 1-10) were isolated from the stems of Kadsura coccinea. Except for 10, these compounds feature a rearranged lanostane skeleton with a 6/6/5/6 tetracyclic ring system, and compounds 1 and 2 are the first examples of 2,3-seco-6/6/5/6-fused tetracyclic triterpenoids. Their structures were established primarily by spectroscopic and spectrometric methods. Additionally, the absolute configuration of 3 was determined by single-crystal X-ray diffraction. Several of the compounds isolated were tested for their anti-HIV-1 and cytotoxic activities.

Five new secondary metabolites produced by a marine-associated fungus, Daldinia eschscholzii.

Five new compounds, including a benzopyran ribonic glycoside, daldiniside A (1), two isocoumarin ribonic glycosides, daldinisides B (2) and C (3), and two alkaloids, 1-(3-indolyl)-2R,3-dihydroxypropan-1-one (4) and 3-ethyl-2, 5-pyrazinedipropanoic acid (5), along with five known compounds (6-10), were isolated from the EtOAc extract of the marine-associated fungus, Daldinia eschscholzii. Their structures were elucidated by extensive physicochemical and spectroscopic properties, besides comparison with literature data. The absolute configurations of compounds 1-3 were corroborated by chemical transformation, GC analysis and X-ray crystallographic analysis. Meanwhile, the absolute configuration of compound 4 and the planar structure of compound 6 were also determined based on the X-ray diffraction analysis. The cytotoxicity of compounds 1-10, antifungal and anti-HIV activities of compounds 1-5 and the in vitro assay for glucose consumption of compounds 1-3 were done in the anti-diabetic model, whereas none showed obvious activity.

Bipolarins A-H, eight new ophiobolin-type sesterterpenes with antimicrobial activity from fungus Bipolaris sp. TJ403-B1.

Bipolarins A-H (1-8), eight new tetracyclic ophiobolin-type sesterterpenes featuring a rare oxaspiro[4.4]nonane moiety, were isolated from cultures of fungus Bipolaris sp. TJ403-B1. Their structures and absolute configurations were elucidated by comprehensive spectroscopic analyses, single-crystal X-ray diffraction experiments, electronic circular dichroism and 13C NMR calculations. Additionally, compound 5 exhibited significant selective antimicrobial activity against Enterococcus faecalis with an MIC value 8 µg·mL-1.

Two New Compounds from Schisandra propinqua var. propinqua.

Schisanpropinoic acid (1), a new bergamotane sesquiterpenoid, and schisanpropinin (2), a new tetrahydrofuran lignan with a rare epoxyethane unit, were identified from the stems and leaves of Schisandra propinqua var. propinqua. Their structures were determined based on comprehensive spectroscopic and mass spectrometric analysis. The absolute configuration of 1 was determined by X-ray analysis. Compounds 1 and 2 were tested for their cytotoxic activity against five human tumor cell lines.

Structural Characterization of Kadcoccinin A: A Sesquiterpenoid with a Tricyclo[4.4.0.0(3,10)]decane Scaffold from Kadsura coccinea.

Kadcoccinin A (1), a cage-like sesquiterpenoid possessing a tricyclo[4.4.0.0(3,10)]decane scaffold, and the biosynthetically related kadcoccinin B (2) were isolated from the stems of Kadsura coccinea. Their structures and absolute configurations were determined from extensive spectroscopic analysis and quantum chemical calculations. Additionally, their cytotoxic and antifungal effects were initially evaluated, and a plausible biosynthetic pathway was proposed.

Kadcoccinones A-F, New Biogenetically Related Lanostane-Type Triterpenoids with Diverse Skeletons from Kadsura coccinea.

Six new lanostane-related triterpenoids, kadcoccinones A-F (1-6), were isolated from Kadsura coccinea. Compound 3 possesses a novel 6/6/9-fused carbocyclic core containing a rare oxabicyclo[4.3.1]decane system. Compounds 4 and 5 are isomers representing the first example of the 18(13 → 12)-abeo-26-norlanostane triterpenoid. The absolute configurations of 1 and 4-6 were defined by X-ray diffraction and experimental ECD spectra, and that of 3 was elucidated by quantum chemical calculations. The plausible biogenetic pathway of 1-6 is postulated.