seco-Prezizanne Sesquiterpenes and Prenylated C6-C3 Compounds from the Fruits of Illicium lanceolatum A. C. Smith.

Two new seco-prezizaane-type sesquiterpenes, 2ß-hydroxy-6-deoxyneoanisatin (1) and 3,4-anhydro-2-oxo-1α-hydroxy-6-deoxyneoanisatin (2), and two new prenylated C6 -C3 compounds, illilanceofunones A (3) and B (4), were obtained from the fruits of Illicium lanceolatum, along with four known prenylated C6 -C3 compounds (5-8). Their structures were proposed through HR-ESI-MS, 1 H, 13 C, and 2D NMR data interpretation. Moreover, the absolute configuration of 1 and 2 were further assigned by single-crystal X-ray diffraction analysis and electronic circular dichroism (ECD) calculations, respectively. Illihenryipyranol A (6) exhibited neuroprotective activity against MPP+ -induced PC12 cell damage in a dose-dependent manner.

Four Highly Oxygenated Sesquiterpenoids from the Fruits of Illicium micranthum Dunn.

Four highly oxygenated sesquiterpenoids, illimicranolides A (1) and B (2), and illicinolides E (3) and F (4), were obtained from the fruits of Illicium micranthum Dunn, as well as one known analog, illicinolide B (5). The chemical structures of 1-4 were determined comprehensively by 1D (1 H and 13 C) and 2D (HMBC, HSQC, 1 H-1 H COSY, and ROESY) NMR, and HR-ESI-MS data. Structurally, compound 1 was an unprecedented sesquiterpenoid with a 5/5/6/5-fused tetracyclic ring system and was the first seco-prezizaane sesquiterpenoid featuring a 11,8-γ-lactone ring. Compounds 3 and 4 were the fifth and sixth examples of illicinolide-type sesquiterpenoids. Moreover, compound 1 demonstrated neurotrophic activity of NGF-induced PC12 cells with differentiation rate of 10.34 % at a concentration of 10 µM.

Spirocyclohexadienone-Type Neolignans with Neuroprotective and Neurite Outgrowth Enhancing Activities from Magnolia liliiflora.

Three rare spirocyclohexadienone-type neolignans, magnoflorins A-C (1-3), and three known analogs (4-6), were isolated from the leaves of Magnolia liliiflora. Magnoflorin D (4) was obtained from natural resources for the first time. The chemical structures and absolute configurations of 1-4 were elucidated through detailed analysis of HR-ESI-MS, IR, 1 H, 13 C, and 2D NMR, and ECD experiments. The absolute configuration of 5 were characterized by X-ray crystallography in present study. Moreover, compounds 4 and 5 displayed moderate neuroprotective activity against corticosterone-induced PC12 cells injury at 20 µM with cell viability of 71.5±0.99 % and 73.0±1.42 %, respectively, compared to the model group with 60.83±0.93 %. Compound 6 could enhance neurite outgrowth of nerve growth factor (NGF)-induced PC12 cells at 10 µM with the differentiation rate of 11.98 %, compared with 20.49 % of 50 ng/ml NGF.

Hypopurolides A - G, Labdane Diterpenoids from Hypoestes purpurea and Their Nitric Oxide Inhibitory Activity.

Seven new labdane diterpenoids, hypopurolides A-G (1-7) were discovered from the aerial part of Hypoestes purpurea, along with one known analog, hypopurin D (8). The structures of 1-7 were characterized based on 1 H-, 13 C-, and 2D-NMR, and HR-ESI-MS spectra. The absolute configurations of 1-7 were defined by single-crystal X-ray diffraction and electronic circular dichroism (ECD) data. Compounds 1-8 were tested for their nitric oxide (NO) inhibitory and cytotoxic effects. Compound 6 displayed moderate inhibitory effect toward LPS-induced NO release in RAW 264.7 cells with an IC50 value of 41.50 µM.

Tetranorlanostane and Lanostane Triterpenoids with Cytotoxic Activity from the Epidermis of Poria cocos.

Two unprecedented tetranorlanostane triterpenoids, poricolides A (1) and B (2), and two new lanostane triterpenoids, 3ß-acetoxy-24-methyllanosta-8,16,24(31)-trien-21-oic acid (3) and 3ß-acetoxylanosta-7,9(11),16,23-tetraen-21-oic acid (4), were isolated from the epidermis of Poria cocos. The structures of 1-4 were determined via analysis of 1 H-, 13 C-, and 2D-NMR, and HR-ESI-MS data, and the absolute configurations of 1 and 3 were established by single-crystal X-ray diffraction analysis. Compounds 1 and 2 were the first report of tetranorlanostane triterpenoid having a δ-lactone ring at C(17). Compounds 3 and 4 were rare lanostane triterpenoids having a double bond between C(16) and C(17). Compounds 1-4 exhibited potent antiproliferative effects against A549, SMMC-7721, MCF-7, and SW480 cancer cell lines with IC50 values from 16.19±0.38 to 27.74±1.12 µM.

Caesalpanins A-C, Three Dimeric Cassane Diterpenoids from the Seeds of Caesalpinia sappan L.

Three dimeric cassane diterpenoids, caesalpanins A-C, were isolated from the seeds of Caesalpinia sappan L., as well as three known compounds. Their structures were determined via analysis of 1D-, 2D-NMR, and HR-ESI-MS data. Caesalpanins A and B were the second and third compounds that presented a nitrogen-containing cassane diterpenoid dimer linked through one ether bond between C-19 and C-20'. Caesalpanin B exhibited moderate cytotoxic activity against MCF-7 cell lines with IC50 value of 29.98 µm. Caesalpanins A and B had weak inhibitory effects against LPS-induced nitric oxide (NO) production in RAW 264.7 macrophages at 50 µm with inhibitory rate of 36.01 % and 32.93 %, respectively.

Sesquiterpenes from the Leaves of Magnolia delavayi Franch. and Their Cytotoxic Activities.

Thirteen sesquiterpenes including eight new ones, magnodelavins A-H (1-8), were obtained from the 95 % ethanolic extract of the leaves of Magnolia delavayi Franch. The structures of the new compounds were determined by exhaustive 1 H-, 13 C-, 2D-NMR, UV, IR, and HR-ESI-MS data, as well as X-ray crystallographic analysis. Compounds 9 and 10 showed potent cytotoxic activities against HL-60, A-549, SMMC-7721, MCF-7, and SW480 human cancer cell lines in vitro using MTS assay.

Hypofolins A - L, ent-Labdane Diterpenoids from the Roots of Hypoestes phyllostachya 'Pink Splash'.

Twelve new ent-labdane diterpenoids, hypofolins A - F (1 - 6) and hypofolins G - L (7a/7b, 8a/8b, and 9a/9b), were isolated from the roots of Hypoestes phyllostachya 'Pink Splash'. Their structures were elucidated by extensive 1D- and 2D-NMR spectroscopic and HR-MS data. The absolute configurations of 1, 2, 5, and 7a/7b were determined by single crystal X-ray diffraction and ECD analysis, as well as chemical transformations. Compounds 7a/7b, 8a/8b, and 9a/9b were isolated as three pairs of interconverting mixture of two isomers between ketone and hemiketal types. Compound 1 showed weak cytotoxicity against SMMC-7721 cell line with IC50 value of 31.40 µm.

Sesquiterpenoids from the twigs and leaves of Fokienia hodginsii.

A rare carotane-type sesquiterpenoid, forkienin A (1), a new eudesmane-type sesquiterpenoid, forkienin B (2), and a new natural eudesmane-type sesquiterpenoid, forkienin C (3), were isolated from the twigs and leaves of Fokienia hodginsii, along with eight known sesquiterpenoids. The structures of the new compounds were elucidated on the basis of their spectroscopic analysis, including 1D and 2D NMR methods. All compounds were evaluated for cytotoxicity against HL-60, SMMC-7721, A-549, MCF-7, and SW480 cell lines.

[A new cassane diterpene from Caesalpinia bonduc].

Five cassane diterpenes were isolated from the 95% ethanol extract of the seeds of Caesalpinia bonduc (Leguminosea) by a combination of various chromatographic methods, including silica gel, Sephadex LH-20, and semi-preparative HPLC. On the basis of spectroscopic techniques, their structures were identified as 3ß-acetoxy-cassa-12,14(17),15-trien-7ß-ol (1), caesalmin C (2), caesall E (3), caesalpinin MJ (4), and 1-deacetylcaesalmin C (5). Among them, compound 1 is a new compound and 2, 4, 5 were isolated from the plant for the first time.

[Chemical Constituents of Inula japonica].

Objective: To study the chemical constituents of Inula japonica. Methods: Silica gel, Sephadex LH-20,MCI and semipreparative HPLC were used to isolate and purify the constituents of Inula japonica,and the chemical structures were elucidated by chemical properties, MS and NMR analysis. Results: 14 compounds were isolated and their structures were identified as ivangustin( 1),1-acetoxy-6α-hydroxyeriolanolide( 2), 1ß-hydroxyalantolactone( 3),tomentosin( 4),11,13-dihydroinuchinenolide B( 5), britanlin A( 6),vomifoliol( 7), 17-hydroxy-16α-ent-kauran-19-oic acid( 8), 12-hydroxygeranylgeraniol ( 9), dihydroquercetin( 10), kaempferol( 11), quercetin( 12), dihydroconiferyl alcohol( 13) and fareanol( 14). Conclusion: Compounds 5,6,9,13 and 14 are isolated from this plant for the first time.

Sesquiterpenoids from Tussilago farfara and their inhibitory effects on nitric oxide production.

Tussilagone (TSL) and its allied sesquiterpenoids were considered as the main active principles of the flower buds of Tussilago farfara, which has been widely used in China as an antitussive herbal medicine. Six new bisabolane-type sesquiterpenoids, tussfararins A-F (1-6), along with 12 known sesquiterpenoids, were isolated from the flower buds of T. farfara. Structures of the new compounds were elucidated by extensive spectroscopic analysis. The biological analysis showed that compounds 1, 3, 6, and 7 inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells with IC50 values of 13.6-24.4 µM.

[Chemical constituents of Eucommia ulmoides].

OBJECTIVE: To study the chemical compositions of Eucommia ulmoides. METHODS: The compounds were isolated and purified from Eucommia ulmoides by silica gel column chromatography, Sephadex LH-20, MPLC packed with MCI gel and semi-preparative HPLC. The structures of these compounds were established on the basis of spectral analyses (1H-NMR, 13C-NMR and MS). RESULTS: Thirteen compounds were obtained,and their structures were identified as betulin (1), syringin (2), pervoside A (3), glucosyringic acid (4), vanillic acid-beta-glucoside (5), geniposide acid (6), aucubin (7), geniposide (8), pinoresinol-4,4'-di-O-beta-D-glucopyranoside (9), syringaresinol di-O-beta-D-glucopyranoside (10), medioresinol di-O-beta-D-glucopyranoside (11), sucrose (12), and ethyl beta-glucopyranoside (13) on the basis of physical characteristics and spectral data. CONCLUSION: Compounds 3 - 5, 12 and 13 are isolated from this plant for the first itme.

Structurally diverse diterpenoids from the seeds of Caesalpinia minax Hance and their bioactivities.

Eight previously undescribed diterpenoids, caesamins A-H (1-8), were separated and identified from the seeds of Caesalpinia minax Hance. Their structures were characterized by extensive spectroscopic data and X-ray crystallographic analysis. Structurally, caesamin A (1) is the first cassane-type diterpenoid with a C23 carbon skeleton containing an unusual isopropyl. Caesamin F (6) represents the first example of cleistanthane diterpenoid from the genus Caesalpinia. Caesamins B (2) and F (6) exhibited inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages with IC50 values of 45.67 ± 0.92 and 42.99 ± 0.24 µM, comparable to positive control 43.69 ± 2.62 µM of NG-Monomethyl-L-arginine. Furthermore, the chemotaxonomic significance of the isolates was discussed.

Labdane-type diterpenoids with cytotoxic and anti-inflammatory activities from the aerial parts of Hypoestes purpurea (L.) R. Br.

Two new ent-labdane diterpenoids, hypoestesins A-B (1-2) and five new labdane diterpenoids, hypopurolides H-L (3-7), were isolated from the aerial parts of Hypoestes purpurea. All of the structures were fully determined based on extensive analysis of 1H, 13C, 2D NMR, and HRESIMS data. The absolute configurations of 1-3 was established through comparing the experimental and calculated ECD curves and the structure of 5 was confirmed by single crystal X-ray diffraction experiment. Compounds 5-7 were unusual C23 labdane diterpenoids having a γ-acetonyl-α, ß-unsaturated γ-lactone unit and each assigned as C-15 epimeric mixture. Furthermore, cytotoxic and anti-inflammatory activities of 3-7 were evaluated. The results showed that 3 had remarkable cytotoxic activity against HL-60, A549, SMMC-7721, MDA-MB-231, and SW480 cancer cell lines with IC50 values ranging from 2.35 to 17.06 µM. Compound 4 showed moderate cytotoxic activity against HL-60 and SMMC-7721 cancer cell lines with IC50 values of 15.12 ± 0.53 and 12.92 ± 0.60 µM, respectively. Furthermore, compound 4 was also found to exhibit inhibitory activity against NO production in RAW 264.7 macrophages with IC50 values of 23.56 ± 0.99 µM, compared to the positive control L-NMMA with an IC50 value of 41.11 ± 1.34 µM.

Anti-pancreatic cancer activity of cassane diterpenoids isolated from the seeds of Caesalpinia sappan mediated by autophagy activation via ROS/AMPK/mTORC1 pathway.

Three undescribed cassane diterpenoids, caesalpanins D-F (1-3), and seven known ones were isolated from the seeds of Caesalpinia sappan. Structures and absolute configurations of 1-3 were elucidated based on the extensive spectroscopic analysis, single-crystal X-ray diffraction analysis, and ECD calculations. Structurally, compound 1 was the first example of 18-norcassane diterpenoid and 2 was a rare 20-norcassane diterpenoid having an unusual five-membered oxygen bridge between C-10/C-18. The anti-proliferative activity of 1, 3, and 4-10 against PANC-1 cells (pancreatic ductal adenocarcinoma cell line) was evaluated, and phanginin H (4) was found to exhibit anti-cancer activity with IC50 value of 18.13 ± 0.63 µM. Compound 4 inhibited PANC-1 cell growth by arresting the cell cycle at G2/M phase via regulation of cyclin-dependent kinases, and the self-renewal and metastasis of PANC-1 cells by suppressing cancer cell stemness. Furthermore, compound 4 induced ROS generation and subsequently activated autophagy, which was demonstrated by the formation of autophagic vacuoles and dynamic change of autophagic flux. The induced ROS accumulation resulted in AMPK activation and subsequently regulation of mTORC1 activity and ULK phosphorylation, indicating that 4 triggered autophagy through ROS/AMPK/mTORC1 pathway. These findings suggested that 4 might potentially be an autophagy inducer for the therapy of pancreatic cancer.

Two new diterpenoids from Excoecaria acerifolia.

A new tigliane diterpenoid, acerifolin A (1), and a new isopimarane diterpenoid, acerifolin B (2), together with two known compounds, were isolated from Excoecaria acerifolia. Their structures were elucidated on the basis of their spectroscopic methods, including 1D and 2D NMR techniques. All of the compounds were evaluated for cytotoxicity against five human cancer cell lines with cisplantin as a positive control.

Eudesmane-type sesquiterpenoids from the aerial parts of Artemisia lavandulaefolia and their anti-pancreatic cancer activities.

Five undescribed eudesmane sesquiterpenoids, artemilavanins A-E, and one undescribed rearranged eudesmane sesquiterpenoid, artemilavanin F, were isolated from the 95% ethanol extract of the aerial parts of Artemisia lavandulaefolia DC., along with ten known compounds. The structures and configurations of undescribed compounds were mainly elucidated by spectroscopic analyses and single-crystal X-ray diffraction analysis. Among all isolated compounds, artemilavanin F exhibited inhibitory activity on PANC-1 pancreatic cancer cells with IC50 of 9.69 ± 2.39 µM. Artemilavanin F inhibited PANC-1 cell proliferation by induction of G2/M cell cycle arrest and apoptosis mediated by downregulation of cyclin-dependent kinases and accumulation of reactive oxygen species. Moreover, artemilavanin F inhibited the colony formation, cell migration and sphere formation of PANC-1 cells, indicating the suppression of stem-cell-like phenotype of PANC-1 cells. Further results confirmed that the expression of cancer stem cell markers such as Bmi1, CD44, CD133 were inhibited by artemilavanin F. Downregulation of epithelial-mesenchymal transition (EMT) markers such as N-cadherin and Oct-4 indicated the potential of artemilavanin F in prevention of metastasis.

Cassane diterpenoids from the seeds of Caesalpinia bonduc and their nitric oxide production and α-glucosidase inhibitory activities.

Ten previously undescribed cassane diterpenoids, cassabonducins A-J, and eleven known compounds were isolated from the seeds of Caesalpinia bonduc. The structures of the undescribed compounds were elucidated by extensive analysis of spectroscopic data (IR, HRESIMS, and 1H, 13C and 2D NMR) and their absolute configurations were determined by the ECD data and single-crystal X-ray diffraction analysis. ε-Caesalpin-Ⅶ was obtained from natural resources for the first time. Cassabonducin A possessed noteworthy inhibitory activity against LPS-induced nitric oxide (NO) production in RAW 264.7 macrophages with IC50 value of 6.12 µM. Cassabonducin D and neocaesalpin N showed moderate α-glucosidase inhibition at the concentration of 50 µM with inhibitory capacities of 47.17% and 43.83%, respectively.

Two new terpene glucosides and antitumor agents from Centipeda minima.

One new monoterpene glucoside minimaoside A (1) and one new sesquiterpene glucoside minimaoside B (2), together with four known terpenoids, were isolated from the whole plants of Centipeda minima (L.) A. Braun et Ashers. Their structures were determined by spectroscopic methods. Compounds 5 and 6 showed weak or moderate cytotoxic activity toward several tumor cell lines.