Longipedlactones A-I, nine novel triterpene dilactones possessing a unique skeleton from Kadsura longipedunculata

Nine novel triterpene dilactones with an unprecedented rearranged pentacyclic skeleton, longipedlactones A-I (1-9), have been isolated from the leaves and stems of Kadsura longipedunculata Finet et Gagnep (Schisandraceae). Their structures were determined on the basis of comprehensive spectroscopic analysis and single-crystal X-ray structure determination. A biogenetic pathway for longipedlactone A (1) was also proposed. Compounds 1-3, 6, and 8 showed significant cytotoxicity against A549, with HT-29 and K562 cell lines having IC₅₀ values of 0.84-11.38 μM in vitro.     

Kadsuphilactones A and B, two new triterpene dilactones from kadsuraphilippinensis

[structure: see text]. Two novel triterpene dilactones, kadsuphilactones A (1) and B (2), were isolated from the Taiwanese medicinal plant Kadsura philippinensis. The structures of 1 and 2 were elucidated on the basis of extensive spectroscopic methods, including two-dimensional NMR techniques, and confirmed by X-ray crystallographic analysis. Kadsuphilactone B (2) exhibited in vitro anti-HBV activity with IC(50) values of 6 microg/mL by HBsAg enzyme immunoassay.     

Kadpolysperins A–N,lanostane triterpene acids possessing rich structure types from Kadsura polysperma

Fourteen new lanostane triterpene acids (1–14), and five known analogues (15–19) were isolated from the stems of Kadsura polysperma. Compound 1, with a rearranged tetracyclic skeleton, is an important biogenic precursor of longipedlactone skeleton. Compounds 2–6 are members of 18(13→12)-abeo-lanostane triterpene acids. The structures of new compounds were elucidated by spectroscopic evidence. Selected compounds were evaluated for their in vitro cytotoxicity against human tumor HL-60, SMMC-7721, A-549, MCF-7, and SW-480 cell lines.     

Lancifodilactone F: a novel nortriterpenoid possessing a unique skeleton from Schisandra lancifolia and its anti-HIV activity

[structures: see text] Lancifodilactone F (1), possessing an unprecedented rearranged pentanortriterpenoid backbone derived from cycloartane, was isolated from the leaves and stems of Schisandra lancifolia (Rehd. et Wils) A. C. Smith. Its structure was established by comprehensive NMR and MS spectroscopic analysis, coupled with single-crystal X-ray experiment. Compound 1 exerted minimal cytotoxicity against C8166 cells (CC50 > 200 microg/mL) and showed anti-HIV activity with EC50 = 20.69 +/- 3.31 microg/mL and a selectivity index > 6.62.     

Structure and anti-HIV activity of micrandilactones B and C, new nortriterpenoids possessing a unique skeleton from Schisandra micrantha

Two new highly oxygenated nortriterpenoids with a unique norcycloartane skeleton, micrandilactones B and C, were isolated from Schisandra micrantha; micrandilactone C exhibited an EC50 value of 7.71 microg/mL (SI > 25.94) against HIV-1 replication with minimal cytotoxicity, and the potent anti-HIV-1 activity and unique structural features of make it a promising lead for therapeutic development of a new generation of anti-HIV drug.     

Daphlongeranines A and B, two novel alkaloids possessing unprecedented skeletons from Daphniphyllum longeracemosum

Two novel alkaloids, daphlongeranines A (1) and B (2), with an unprecedented ring system, were isolated from the fruits of Daphniphyllum longeracemosum. Their unique structures and relative stereochemistries were established on the basis of spectroscopic and single-crystal diffraction analysis. The proposed biosynthetic pathway was also discussed. Compounds 1 and 2 showed weak inhibition on platelet aggregation.     

Neoverataline A and B, two antifungal alkaloids with a novel carbon skeleton from Veratrum taliense

Bioassay-guided fractionation of the ethanol extract of the roots and rhizomes of Veratrum taliense yielded two new and thirteen known steroidal alkaloids. The structures of the two new compounds, neoverataline A and B, were established by extensive spectroscopic analyses to be 3,4-secocevane-4,9-olid-14,15,16,20-tetra-ol-3-oic acid and 3,4-secocevane-4,9-olid-7,14,15,16,20-penta-ol-3-oic acid, respectively, and are a novel carbon skelton. All of the fifteen alkaloids were subjected to in vitro antifungal assays, which showed that the verazine- (veramitaline, stenophylline B, stenophylline B-3-O-β-d-glucopyranoside, veramiline-3-O-β-d-glucopyranoside) and jerveratrum-type (jervine, jervine-3-O-β-d-glucopyranoside) alkaloids exhibited strong antifungal activities against the phytopathogenic fungus Phytophthora capisis with MICs of 160, 120, 160, 80, 80 and 120 μg·L⁻¹, respectively. Furthermore, the verazine-type alkaloids stenophylline B, stenophylline B 3-O-β-d-glucopyranoside and veramiline 3-O-β-d-glucopyranoside were shown to also inhibit the growth of another fungal phytopathogen Rhizoctonia cerealis with MICs of 160, 120 and 120 μg mL⁻¹. The MICs of triadimefon (an antifungal agrochemical used herein as a positive control) against P. capisis and R. cerealis were 120 and 80 μg mL⁻¹, respectively. A preliminary structure-activity relationship regarding these alkaloids has been formulated.     

Echinopines A and B: sesquiterpenoids possessing an unprecedented skeleton from Echinops spinosus

Echinopines A (1) and B (2), novel sesquiterpenoids with an unprecedented rearranged skeleton named echinopane, were isolated from the roots of Echinops spinosus. The structures were elucidated by extensive spectroscopic analysis. The relative configuration of 1 was assigned by a combination of NOESY correlations and a simulation analysis. A plausible biosynthetic pathway for echinopane was discussed.     

Abiestetranes A and B,two unique tetraterpenes from Abies fabri

Abiestetranes A (1) and B (2), two unique tetraterpenes formed by Diels–Alder cycloaddition between a lanostane triterpenoid and a monoterpenoid, were isolated from Abies fabri. Their structures were elucidated by extensive analysis of NMR data. The electronic circular dichroism was utilized to assign the absolute configuration of 1. Compounds 1 and 2 showed significant cytotoxic activities against ZR-75-30 tumor cell with IC₅₀ values of 6.26 and 1.63 μg/mL, respectively.     

Fallaxosides B1 and D3, triterpene glycosides with novel skeleton types of aglycones from the sea cucumber Cucumaria fallax

Two unprecedented triterpene glycosides, fallaxosides B₁ and D₃ with aglycones of new skeletal types were isolated from the sea cucumber Cucumaria fallax (Cucumariidae, Dendrochirotida). The first of these aglycones is formed as result of intramolecular aldol condensation of a precursor having 1,6-diketone functionality, while the second one by pinacol-pinacolone-like rearrangement of another precursor, probably containing 7,8,9-trihydroxy fragment (or its 8,9-epoxy-7-hydroxy analog). The structures of these compounds were established by analysis of 1D, 2D NMR, ESI MS and CD data with using the quantum-chemical calculations.     

Achilleol B: a new tricyclic triterpene skeleton from Achillea odorata L

Achilleol B ( ), a new tricyclic triterpene, has been isolated from Achillea odorata L. and its structure established on the basis of its NMR data obtained through n.O.e., short and long-range homo and heteronuclear correlation experiments and other spectroscopic evidence.     

Two novel alkaloids with a unique fused hexacyclic skeleton from Daphniphyllum subverticillatum

Two novel major alkaloids, deoxycalyciphylline B (1) and deoxyisocalyciphylline B (2) with a unique fused hexacyclic skeleton, together with a quite recently reported alkaloid calyciphylline B (3), were isolated from the stem of Daphniphyllum subverticillatum. Their structures were established by spectral methods and chemical evidence, especially 2D NMR techniques. The structure of 1 was further confirmed by a single-crystal X-ray diffraction determination.     

Three new lignans, longipedunins A-C, from Kadsura longipedunculata and their inhibitory activity against HIV-1 protease

Three new lignans, longipedunins A (1), B (2) and C (3), together with three known compounds, benzoyl-binankadsurin A (4), acetyl-binankadsurin A (5) and schisanlactone A (6), were isolated from Kadsura longipedunculata. Their structures and stereochemistry were determined by spectral and single-crystal X-ray analyses. Compounds 1 and 6 showed appreciable inhibitory activity against HIV-1 protease with IC50 values of 50 and 20 microM, respectively.     

Lathyranone A: a diterpenoid possessing an unprecedented skeleton from Euphorbia lathyris

Lathyranone A (1), a novel diterpenoid with a rearrangement skeleton, along with a known diterpenoid, Euphorbia factor L(11) (2), was isolated from the seeds of Euphorbia lathyris. The structure and relative stereochemistry of 1 were elucidated by extensive spectroscopic analysis. A possible biosynthetic pathway for lathyranone A (1) was proposed.     

A novel anti-HBeAg homolignan, taiwanschirin D from Kadsura matsudai

A novel C19 homolignan, taiwanschirin D (1), possessing a 3,4-(1-[(Z)-2-methoxy-2-oxoethylidenel)pentano (2,3-dihydrobenzo[b]furan)-3(2-oxoacetate) skeleton, was isolated from the stem of Kadsura matsudai Hayata. Its structure was determined from physical and spectral data including 2D NMR spectra. The Anti-HBeAg test revealed that taiwanschirin D (1) had moderate activity at a concentration of 94.3 microM (50 microg/ml).     

Schilancidilactones A and B: two novel tetranortriterpenoids with an unprecedented skeleton from Schisandra lancifolia

Schilancidilactones A (1) and B (2), two novel tetranortriterpenoids possessing an unprecedented skeleton, have been isolated from the stems of Schisandra lancifolia. Their structures were elucidated on the basis of extensive spectroscopic analysis. The relative configurations of 1 were further determined by single-crystal X-ray crystallography. Compounds 1 and 2 were tested for their cytotoxicity against four tumor cell lines NB4, A549, SH-SY5Y, and PC-3, and compound 1 was further tested for its anti-HIV-1 activity.     

A novel triterpene from Centella asiatica

A novel triterpene, 2alpha,3beta,20,23-tetrahydroxyurs-28-oic acid (1), was isolated from the aerial part of Centella asiatica. Its structure was elucidated by spectroscopic methods, including 2D-NMR spectra. It displayed no activity against Hela and A549 cell lines at concentrations of 10 and 30 microg/mL, respectively.     

Penicillones A and B, two novel polyketides with tricyclo [5.3.1.0] undecane skeleton, from a marine-derived fungus Penicillium terrestre

Two novel polyketides, penicillones A (1) and B (2), with tricyclo [5.3.1.0^3,8] undecane skeleton, were isolated from Penicillium terrestre. Their structures and relative stereochemistries were determined on the basis of spectroscopic methods. The absolute configuration of 2 was established by the modified Mosher’s method, while that of 1 was deduced from the similar CD absorptions of 1 and 2. Compound 1 showed weak cytotoxicities against P338 and A-549 cell lines, while 2 was inactive against P388.     

Micrandilactone A: a novel triterpene from Schisandra micrantha

[structure: see text] A novel nortriterpene, micrandilactone A, was isolated from the medicinal plant Schisandra micrantha. This is the first example of an unusual, natural, highly oxidized cycloartane skeleton with a biosynthetically modified eight-membered ring D isolated from the family Schisandraceae.     

Xylocarpanoids A and B, unique C28 skeleton limonoids from Xylocarpus granatum

One novel tetranortriterpenoid derivative, xylocarponoid A, representing the first example of C28 skeleton limonoid, was isolated from the seeds of the Chinese mangrove, Xylocarpus granatum. Its C-1′-epimer, xylocarponoid B, was formed in CDCl₃. Their structures were elucidated by extensive spectroscopic analysis. A plausible biosynthetic pathway of xylocarponoid A was proposed.