Chemical constituents from the twigs with leaves of Tetradium trichotomum.

Twelve compounds, comprising of four new ones, 6ß,7α-limondiol (1) and ethyl 19-hydroxyisoobacunoate diosphenol (2), N-benzoyl 3-prenyltyramine (9) and 9-O-methyl integrifoliodiol (12), were isolated from the twigs with leaves of Tetradium trichotomum. The structures were elucidated by analysis of MS, NMR, and single-crystal X-ray diffraction. Compounds 1, 6, 8, 9 and 12 exhibited immunosuppressive activities in vitro against the proliferation of ConA-induced T lymphocytes and LPS-induced B cells.

Alopecines A-E, five chloro-containing matrine-type alkaloids with immunosuppressive activities from the seeds of Sophora alopecuroides.

Alopecines A-E (1-5), five unusual matrine-type alkaloids featuring with an additional dichlorocyclopropane (1-3) or a di/tri-chloromethyl (4/5) attached on the D ring, were isolated from the seeds of Sophora alopecuroides. Their structures and absolute configurations were elucidated by extensive spectroscopic techniques, and X-ray diffraction analyses or time-dependent density functional theory-based electronic circular dichroism (TDDFT-ECD) calculations. Alkaloid 4 exhibited potent inhibitory effects on the proliferation of ConA-induced T lymphocytes or LPS-induced B cells with IC50 value of 3.98 or 3.74 µM, respectively.

The synthesis of dendroflorin.

The first synthesis of dendroflorin has been achieved in 10 steps with an overall yield of 5.5%. The key step in the synthesis features the biphenyl structure is built through Suzuki-Miyaura reaction. In addition, the ortho-localization effect induced by aromatic substituent during the bromination of intermediate 8 is also observed and discussed.

Triterpenoids from the barks of Terminalia chebula.

Two new triterpenoids, termichebuloside A (1), an unusual dimeric triterpenoid saponin, and termichebulolide (2), an oleanolic acid-type lactone, along with 11 known triterpenoids, were isolated from MeOH extract of the barks of Terminalia chebula. The structures of 1 and 2 were elucidated to be arjunglucoside I-(3-O-19',23-O-19')-18,19-seco-19-hydroxyarjunglucoside I (1) and 2α,3ß,23-trihydroxyolean-11,13(18)-dien-28,19ß-olide (2), respectively, on the basis of spectroscopic evidences and biogenetic consideration.

The resolution of aglinin A epimers and their NMR assignments.

Aglinin A (1) is a mixture of C(24)-epimeric 20S,24-epoxy-24,25-dihydroxy-3,4-secodammar-4(28)-en-3-oic acid and present in plants of the family Meliaceae. The two epimers of 1 were resolved through an acetonide reaction, and the absolute configurations of two derivatives were deduced by the analysis of their (13)C NMR differences induced by γ-gauche or steric effect. Based on it, the (13)C NMR assignment of 24R-1 and 24S-1 was also established.

B-seco Limonoids with anti-inflammatory activity from Tetradium fraxinifolium (Hook.) T.G.Hartley.

Fraxinifolines A-F (1-6), six new B-seco limonoids, together with four known A,D-di-seco ones, were isolated from the twigs with leaves of Tetradium fraxinifolium. Their structures with absolute configurations were elucidated on the basis of analysis of MS, NMR, single-crystal X-ray diffraction and biogenetic pathway. An anti-inflammatory bioassay in vitro showed limonoids 1-3 had significant immunosuppressive effect against the production of pro-inflammatory cytokines (IL-1ß and/or TNF-α) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells.

Arylnaphthalene lignan glycosides and other constituents from Phyllanthus reticulatus.

Two new arylnaphthalene lignan glycosides, named reticulatusides A (1) and B (2), together with eight known compounds were isolated from the 95% EtOH extract of the whole plant of Phyllanthus reticulatus. The structures of the new compounds were elucidated by spectroscopic methods.

Monoterpene indole alkaloids from Melodinus cochinchinensis (Lour.) Merr.

Melodicochinines A - D (1-4), four new monoterpene indole alkaloids (MIAs), along with 21 known ones, were isolated from the stems and twigs of Melodinus cochinchinensis. Their structures were elucidated on the basis of extensive spectroscopic analysis. A ubiquitin-rhodamine 110 assay showed that 11-methyloxytabersonine had potential inhibitory effect against ubiquitin-specific protease 7 (USP7).

Tryptamine derivatives as novel non-nucleosidic inhibitors against hepatitis B virus.

A series of tryptamine derivatives were synthesized and evaluated for their anti-hepatitis B virus (HBV) activity and cytotoxicity in the HepG2.2.15 cell line. The preliminary SAR was discussed. Compounds 2e and 4a showed potent antiviral activity (IC(50)=0.4 and <1 µM, respectively) and low cytotoxicity (CC(50)=40.6 and >25 µM, respectively).

Minor dammarane saponins from the hongshen extract of Shenmai injection.

A new dammarane-type triterpenoid saponin, (20R)-ginsenoside ST(2) (1), along with five known saponins was isolated from the hongshen extract of Shenmai injection. The structure of 1 was elucidated to be (20R)-dammar-23(E)-ene-3ß,6α,12ß,20,25-pentol 6-O-ß-D-glucopyranoside by means of spectroscopic methods.

Polycyclic polyprenylated acylphloroglucinols from Hypericum choisianum.

Twenty-one polycyclic polyprenylated acylphloroglucinols, including three new compounds named as hyperichoisins A (3), B (14) and C (21), were isolated from the aerial parts of Hypericum choisianum. The structures of those new compounds were elucidated by analysis of mass, NMR data, and chiroptical properties. A bioassay showed that otogirinin B had significant inhibitory effect on cell proliferation of A549.

Lycopodium alkaloids from Huperzia serrata.

A new lycopodane-type Lycopodium alkaloid, 6α-hydroxy-5,15-oxide-lycopodane (1), and seven known alkaloids were isolated from the whole plants of Huperzia serrata. Their structures were elucidated by means of spectroscopic methods. 12-Deoxyhuperzine O (2) was reported as a naturally occurring alkaloid for the first time, and showed an antagonist effect on the N-methyl-d-aspartate receptor with an IC(50) value of 0.92 µM.

Polyprenylated acylphloroglucinols as deubiquitinating protease USP7 inhibitors from Hypericum hookerianum.

Hookerianones A - E (1-5), five new polyprenylated acylphloroglucinols (PPAPs), along with six known ones, were isolated from the aerial parts of Hypericum hookerianum. Their structures were elucidated by analyses of MS, NMR, chiroptical properties, biogenetic pathway, and/or single crystal X-ray diffraction. A ubiquitin-rhodamine 110 assay showed that furohyperforin and hypercalin C, two representative PPAPs in this plant, inhibited more than 90% USP7 at the concentration of 10 µM.

Triterpenoids, megastigmanes and hydroxycinnamic acid derivatives from Anisomeles indica.

Six triterpenoids (1-6), four megastigmanes (7-10) and five hydroxycinnamic acid derivatives (11-15) were isolated from the aerial part of Anisomeles indica (Lamiaceae). Of these components, compound 1 was identified to be a new triterpenoid with the structure of 2α,3α,19α-trihydroxyurs-12,20(30)-dien-28-oic acid based on extensive analysis of MS, 1D and 2D NMR spectroscopic data, while compounds 2-13 were obtained for the first time from Anisomeles species.

Diverse lignans with anti-inflammatory activity from Urceola rosea.

Seventeen structurally diverse lignans, comprising six new compounds, ecdysanols A (1), B (11), C - E (13-15), and F (17), were isolated from the caulis of Urceola rosea. The structures and absolute configurations of these new compounds were elucidated by means of extensive analysis of mass and NMR data, as well as chiroptical properties. A bioassay in vitro showed that all lignans possessed anti-inflammatory effects by inhibiting the production of TNF-α, NO and/or IL-6 in LPS-stimulated RAW264.7 cells. Ecdysanol F (17) showed the most strongly effect against NO and IL-6 levels.

Flueggenoids A - E, new dinorditerpenoids from Flueggea virosa.

A phytochemical investigation on the twigs and leaves of Flueggea virosa (Euphorbiaceae) led to the isolation of flueggenoids A - E (1-5), five new 13-methyl-ent-podocarpanes, together with eleven known compounds (6-16). Their structures and absolute configurations were elucidated on the basis of extensive MS and NMR data analysis, and/or single-crystal X-ray diffraction, time-dependent density functional theory (TDDFT)-based electronic circular dichroism (ECD) calculations, and chemical transformation. All isolates were evaluated for anti-HCV activity, the results showed that terpenoids of F. virosa had nonnegligible contribution for the anti-HCV activity.

[Terrain gradient effect of ecosystem service value in middle reach of Yangtze River, China]. / 长江中游地区生态系统服务价值的地形梯度效应.

Using land use data in the year 1995, 2005 and 2014, this study estimated the ecosystem service value (ESV) in each county located in the middle reach of Yangtze River and analyzed its spatiotemporal variation features and terrain gradient effects based on "the equivalent value per unit area of ecosystem services in China". The results showed that ESV in the middle reach of Yangtze River was generally higher in mountainous area but lower in plain region, with an obvious terrain gradient effect. Specifically, the relationship of the relief degree of land surface (RDLS) and the ESV showed significant logarithm function at county scale with a high curve fitting degree of 0.53. The ESV increased from 400.35×104 yuan·km-2 to 554.57×104 yuan·km-2 with the increasing RDLS (grade 1-5) in 2014. During 1995-2004, the ecosystem service value variation changed from decreasing to stable with the increases of the RDLS. With a perspective of ecosystem service values, the value of food production and waste treatment service value decreased with the increase of the RDLS, while the others increased in general, such as the production of raw materials and gas regulation service value, because of the influences of dynamic land use structure in varied topography and distinct dominant ecosystem services from different land types.

Limonoids from the fruits of Swietenia macrophylla with inhibitory activity against H2O2-induced apoptosis in HUVECs.

The fruits of Swietenia macrophylla (skyfruits) are commercially used as healthcare products to improve blood circulation. An investigation of active ingredients of skyfruits led to the isolation of four new limonoids, swietemacrolides A-D (1-4), together with ten known limonoids (5-14) and one proto-limonoid (15). Their structures were elucidated on the basis of MS and NMR data analysis. Swietemacrolide C (3) at the concentration of 10 µM showed significant protective effect on H2O2-induced apoptosis in human umbilical vascular endothelial cells (HUVECs), while swieteliacate D (5) displayed moderate anti-apoptotic activity.

Highly oxygenated and structurally diverse diterpenoids from Euphorbia helioscopia.

A phytochemical investigation on the aerial part of Euphorbia helioscopia (Euphorbiaceae) led to the isolation of 22 highly oxygenated diterpenoids with structural types of ent-abietane, ent-kaurane, lathyrane, ent-atisane and ingenane. 17 of them, named euphelionolides A - N, 16-epi-18-hydroxy-abbeokutone, as well as eupheliotriols A and B, were identified to be previously undescribed compounds by extensive analysis of spectroscopic data. The stereostructures of euphelionolides A - K were determined by single crystal X-ray diffraction combined with analysis of substituent effects and comparison of optical characteristics. Eupheliotriol B is the first example of natural occurring lathyrol with 12Z-ene, while ent-atisanes are the first reported from the title plant. Furthermore, euphelionolides F and L exhibited significant cytotoxicity against MCF-7 and PANC-1 cell lines.

Lamiolactone, a new iridoid lactone from Lamiophlomis rotata.

Lamiolactone (1), a new iridoid lactone, together with five known iridoids, were isolated from the 95% EtOH extract of the roots of Lamiophlomis rotata. The structure of 1 was elucidated to be methyl antirrhinolide-4-carboxylate on the basis of spectroscopic analysis.