α‐Glucosidase Inhibitory Xanthones from the Roots of Garcinia fusca

Two new compounds, fuscaxanthones J ( 1 ) and K ( 2 ), together with eight known xanthones ( 3 – 10 ) were isolated from an ethyl acetate extract of the roots of Garcinia fusca. Their structures were determined using spectroscopic methods, mainly 1D‐ and 2D‐NMR. α‐Glucosidase inhibitory activity of the isolated compounds was evaluated and fuscaxanthone J ( 1 ) showed the most significant effect with an IC₅₀ value of 8.3 ± 1.8 μm (compared with acarbose, IC₅₀ = 214.5 ± 2.3 μm ).     

Two New Dolabrane Diterpenes from the Chinese Mangrove Ceriops tagal

Two new dolabrane diterpenes, tagalenes J and K ( 1 and 2 ), together with eleven known analogues ( 3 – 13 ), were isolated from the ethanolic extract of the Chinese mangrove Ceriops tagal. The structures of these compounds were determined by extensive spectroscopic analysis, including 1D‐, 2D‐NMR and HR‐ESI‐MS, as well as the comparison with data in the literatures. Cytotoxicities of isolated compounds against MCF‐7, SW480, HepG2, HeLa, PANC‐1, and A2058 cancer cell lines were also evaluated. Compound 4 exhibited weak cytotoxic activity against SW480, HeLa, and PANC‐1 cell lines with IC₅₀ values of 27.7, 22.2, and 17.6 μm , respectively.     

Four New Diterpenoid Alkaloids from the Roots of Aconitum carmichaelii

Aconitum carmichaelii Debeaux is a widely used traditional Chinese medicine and an important source of clinical drugs, of which the parent and lateral roots are known as ‘Chuanwu’ and ‘Fuzi’, respectively. Four new C₁₉‐diterpenoid alkaloids, carmichasines A – D ( 1 – 4 ), were isolated from the roots of Aconitum carmichaelii, together with twelve known compounds ( 5 – 16 ). Their structures were elucidated via spectroscopic analyses, including HR‐ESI‐MS, IR, and NMR. Carmichasine A ( 1 ) is the first natural C₁₉‐diterpenoid alkaloid possessing a cyano group. Most of the diterpenoid alkaloids isolated were C₁₉‐category, which might provide further clues for understanding the chemotaxonomic significance of this plant. The cytotoxicity of the new compounds was also investigated against several human cancer cell lines, including MCF‐7, HCT116, A549, and 786‐0, and none of them showed considerable cytotoxic activity.     

Triterpenes and Meroterpenes with Neuroprotective Effects from Ganoderma leucocontextum

Ganoderma leucocontextum is a well‐known medicinal mushroom cultivated in the Tibet Plateau of China. Chemistry investigation on the fruiting bodies of this mushroom resulted in the isolation of sixteen secondary metabolites including three new lanostane triterpenes, ganoleucoins Q – S ( 1 – 3 ), as well as thirteen known compounds ( 4 – 16 ). The structures of compounds 1 – 3 were determined by NMR, MS, CD spectral analysis, and chemical derivation method. The neuroprotective effects of compounds 1 – 16 were tested on PC12 cells. Compounds 1 and 2 showed protective effects against the H₂O₂ induced damage with the survival rate of 83.19 ± 0.92%, 73.37 ± 1.25% at the concentration of 200 μm , respectively. Meanwhile, compounds 1 and 2 induced neurite outgrowth at 50 – 200 μm . The results from this study suggested that G. leucocontextum and its metabolites may be potential functional food ingredients for the prevention of neurodegenerative diseases.     

Tricalycoside,a New Cerebroside from Tricalysia coriacea (Rubiaceae)

A new cerebroside, named as tricalycoside ( 1 ), was isolated from the CH₂Cl₂/MeOH (1:1) extract of twigs and leaves of Tricalysia coriacea using repeated silica gel open column chromatography followed by preparative TLC and Sephadex LH‐20, together with six known compounds ( 2 – 7 ). The structure of the new compound was determined by analysis of 1D‐ and 2D‐NMR, MS data, chemical conversion, and by comparison of these data with those from the literature. Tricalycoside ( 1 ) possessed a weak antibacterial activity against Klebsiella pneumoniae (MIC = 75 μg/mL).     

Sesquiterpene Lactones with COX‐2 Inhibition Activity from Artemisia lavandulaefolia

Two new sesquiterpene lactones, artelavanolides A ( 1 ) and B ( 2 ), and four known sesquiterpene lactones ( 3 – 6 ) were isolated from the leaves of Artemisia lavandulaefolia. Their structures were elucidated based on the analysis of spectroscopic data (1D, 2D‐NMR and HR‐ESI‐MS). The absolute configuration of 1 was determined by the analysis of single‐crystal X‐ray diffraction data. Artelavanolide A ( 1 ) is a rare sesquiterpene lactone possessing an unusual skeleton with the linkage of Me(14)–C(1) that is probably formed through a rearrangement of the guaiane‐type sesquiterpenoids. Artelavanolide B ( 2 ) is a new highly unsaturated guaianolide. Compounds 1 – 6 were tested for activities on the inhibition of COX‐2 enzyme in vitro. All of compounds exhibited inhibitory activity against COX‐2 with IC₅₀ values ranging from 43.29 to 287.07 μm compared with the positive control, celecoxib (IC₅₀ = 18.10 μm ). Among them, 3 showed the best COX‐2 inhibitory activity with an IC₅₀ value of 43.29 μm .     

Terpenes from Euphorbia antiquorum and Their in Vitro Anti‐HIV Activity

Three new compounds ( 1 – 3 ), including two euphane type triterpenes, 24,24‐dimethoxy‐25,26,27‐trinoreuphan‐3β‐ol ( 1 ) and (24S)‐24‐hydroperoxyeupha‐8,25‐dien‐3β‐ol ( 2 ), and an ent‐atisine diterpene, ent‐atisane‐3α,16α,17‐triol ( 3 ), were isolated from an acetone extract of the stems of Euphorbia antiquorum, together with eight known diterpenes ( 4 – 11 ). The structures of compounds ( 1 – 11 ) were elucidated using NMR and MS spectroscopic methods. Compound 7 showed moderate activity against HIV‐1 replication in vitro (EC₅₀ = 1.38 μm ).     

Piptadenin,a Novel 3,4‐Secooleanane Triterpene and Piptadenamide,a New Ceramide from the Stem Bark of Piptadeniastrum africanum (Hook.f.) Brenan

Piptadenin ( 1 ), a new triterpene along with piptadenamide ( 10 ), a new ceramide, have been isolated from the AcOEt‐soluble fraction of the MeOH extract of the stem bark of Piptadeniastrum africanum along with nine known compounds, 1‐O‐[(3β,22β)‐3,22‐dihydroxy‐28‐oxoolean‐12‐en‐28‐yl]‐β‐d ‐glucopyranose ( 2 ), 22β‐hydroxyoleanic acid ( 3 ), oleanic acid ( 4 ), lupeol ( 5 ), betulinic acid ( 6 ), 5α‐stigmasta‐7,22‐dien‐3β‐ol ( 7 ), 5α‐stigmasta‐7,22‐dien‐3‐one ( 8 ), (3β)‐stigmast‐5‐en‐3‐yl β‐d ‐glucopyranoside ( 9 ) and 2,3‐dihydroxypropyl hexacosanoate ( 11 ). Except for compound 11 , all the isolated compounds are reported for the first time from this plant. The structures of the isolated compounds were elucidated by spectroscopic data including 1D and 2D NMR. The pure compounds 1 – 11 were subjected to the pharmacological screening and compounds 2 , 5 – 7 and 9 exhibited potent urease inhibitory activity with IC₅₀ value of 25.8, 28.9, 30.1, 31.8 and 32.7 μm , respectively, whereas compound 1 showed moderate activity (IC₅₀ = 98.7 μm ). The potent urease inhibitory activity supplemented the previous literature reports and medicinal uses of this plant.     

Popolohuanones G – I,Dimeric Sesquiterpene Quinones with IL‐6 Inhibitory Activity from the Marine Sponge Dactylospongia elegans

Chemical investigation of the marine sponge Dactylospongia elegans, collected from the South China Sea, afforded three new dimeric sesquiterpene quinones, popolohuanones G – I ( 1 – 3 ), together with two known analogs, popolohuanones B ( 4 ) and C ( 5 ). The new structures were determined by HR‐ESI‐MS and 1D‐ and 2D‐NMR analyses. All the five compounds showed no cytotoxic activity against five human cancer cell lines, while popolohuanone H ( 2 ) showed potent inhibitory activity against IL‐6, an inflammatory cytokine, at the concentration of 10 μm .     

Oplopane Sesquiterpenes from Ligularia knorringiana and Their Anti‐Complementary Activity

Three new oplopane sesquiterpenes, knorringianalarins D – F ( 1 – 3 , respectively), and five known analogues ( 4 – 8 , respectively), were isolated from the roots and rhizomes of Ligularia knorringiana. The structures of three new compounds were identified as 4‐acetoxy‐11α,12‐epoxy‐2β‐hydroxy‐3β‐(2‐methylbutyryloxy)‐9α‐(4‐methylsenecioyloxy)oplop‐10(14)‐ene ( 1 ), 3β,4‐diacetoxy‐9α‐(4‐acetoxy‐4‐methylsenecioyloxy)‐11α,12‐epoxy‐8α‐(2‐methylbutyryloxy)oplop‐10(14)‐ene ( 2 ), and (1R,5R,6R,7R,9R)‐5,9,11‐trihydroxy‐4,15‐dinoroplop‐10(14)‐en‐3‐one ( 3 ) based on spectroscopic methods including 1D‐ and 2D‐NMR, mass spectrometry, and CD spectroscopy techniques. All compounds were evaluated for their anti‐complementary activity on the classical pathway of the complement system in vitro. Among which, three oplopane sesquiterpenes ( 3 , 7 , and 8 ) exhibited better anti‐complementary effects with CH₅₀ values ranging from 0.33 to 0.89 mm , which are plausible candidates for developing potent anti‐complementary agents.     

Cytotoxic Tetraprenylated Alkaloids from the South China Sea Gorgonian Euplexaura robusta

Nine achiral tetraprenylated alkaloids, including three new compounds, named malonganenones I–K ( 1 – 3 , resp.), together with six known analogs, 4 – 9 , were isolated from the gorgonian Euplexaura robusta collected from Weizhou Island of Guangxi Province, China. The structures of compounds 1 – 3 were elucidated by extensive spectral analyses, especially of their 1D‐ and 2D‐NMR data. Compounds 1, 4, 6 , and 7 showed moderate cytotoxicities against K562 and HeLa tumor cell lines with IC₅₀ values ranging from 0.35 to 10.82 μM . Compound 6 also showed moderate inhibitory activity against c‐Met kinase at a concentration of 10 μM .     

6,7-seco-ent-kaurane diterpenoids from Isodon sculponeatus with cytotoxic activity

Six new 6,7‐seco‐ent‐kaurane diterpenoids, sculponeatins N–S ( 1 – 6 , resp.), together with eleven known analogues, 7 – 17 , were isolated from the aerial parts of Isodon sculponeatus. The structures of compounds 1 – 6 were elucidated by spectroscopic methods including extensive 1D‐ and 2D‐NMR experiments, as well as HR‐ESI‐MS analysis. All diterpenoids obtained were assayed for their cytotoxic activity against K562 and HepG2 human tumor cell lines. Among them, compound 1 showed the most significant cytotoxicity with the IC₅₀ values of 0.21 and 0.29 μM , respectively. The structure–activity relationships are discussed.     

Four New Diterpenoid Alkaloids from The Roots of Aconitum coreanum

Four new hetisine‐type C₂₀‐diterpenoid alkaloids, named as coreanines A–D ( 1 – 4 ), were isolated from the roots of Aconitum coreanum, together with thirteen known alkaloids ( 5 – 17 ). Their structures were elucidated by extensive spectroscopic methods including IR, HR‐ESI‐MS and NMR techniques. All the isolated compounds were screened for the acetylcholinesterase (AChE) inhibitory effects, and none of them showed considerable inhibitory activity.     

New Cytotoxic Bibenzyl and Other Constituents from Bauhinia ungulata L. (Fabaceae)

A new bibenzyl, 2′‐hydroxy‐3,5‐dimethoxy‐4‐methylbibenzyl ( 1 ) and four known compounds identified as 2′‐hydroxy‐3,5‐dimethoxybibenzyl ( 2 ), liquiritigenin ( 3 ), guibourtinidol ( 4 ) and fisetinidol ( 5 ) were isolated from the roots of Bauhinia ungulata L. Phytochemical investigations of the stems of B. ungulata led to the isolation of the known compounds identified as liquiritigenin ( 3 ), guibourtinidol ( 4 ), fisetinidol ( 5 ), taraxerol ( 6 ), betulinic acid ( 7 ), taraxerone ( 8 ), glutinol ( 9 ), a mixture of sitosterol ( 10 ) and stigmasterol ( 11 ), pacharin ( 12 ), naringenin ( 13 ) and eriodictyol ( 14 ). The structures of these compounds were elucidated on the basis of their spectral data (IR, MS, 1D‐ and 2D‐NMR). The cytotoxicity of the bibenzyl 1 has been evaluated against four human cancer cell lines, showing the IC₅₀ values of 4.3 and 6.5 μg ml^?1 against pro‐myelocytic leukemia (HL‐60) and cervical adenocarcinoma (HEP‐2) cell lines, respectively. This article also registers for the first time the ¹³C‐NMR data of the known bibenzyl 2 .     

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 .     

Bioactive Neolignans and Other Compounds from Magnolia grandiflora L.: Isolation and Antiplasmodial Activity

Bioassay‐guided fractionation of a methanol extract of Magnolia grandiflora against Plasmodium falciparum yielded two new ( 1 and 2 ) and six known ( 3 – 8 ) bioactive compounds. The structures of the new compounds were assigned by mass spectrometric and 1D‐ and 2D‐NMR data. Known compounds were identified by comparison of ¹H‐NMR and MS data with literature data. The two known neolignans 3 and 4 showed moderate antiplasmodial activity with the IC₅₀ values of 2.8 ± 0.1 and 3.4 ± 0.1 μm , respectively. Weak antiplasmodial activity was recorded for compounds 1 , 2 , 5 , 6 , 7 , and 8 , with the IC₅₀ values of 38 ± 2, 23 ± 2, 16.5 ± 0.2, 86 ± 1, 44 ± 4, and 114 ± 9 μm , respectively.     

Bergamotane Sesquiterpenes with Alpha‐Glucosidase Inhibitory Activity from the Plant Pathogenic Fungus Penicillium expansum

Two new bergamotane sesquiterpene lactones, named expansolides C and D ( 1 and 2 ), together with two known compounds expansolides A and B ( 3 and 4 ), were isolated from the plant pathogenic fungus Penicillium expansum ACCC37275. The structures of the new compounds were established by detailed analyses of the spectroscopic data, especially 1D‐, 2D‐NMR, and HR‐ESI‐MS. In an in vitro bioassay, the epimeric mixture of expansolides C and D ( 1 and 2 ) (in a ratio of 2:1 at the temprature of the bioassay) exhibited more potent α‐glucosidase inhibitory activity (IC₅₀ =0.50 ± 0.02 mm ) as compared with the positive control acarbose (IC₅₀ = 1.90 ± 0.05 mm ). To the best of our knowledge, it was the first report on the α‐glucosidase inhibitory activity of bergamotane sesquiterpenes.     

Diterpenoids from Wedelia prostrata and Their Derivatives and Cytotoxic Activities

One new ent‐kaurane diterpenoid, 11β,16α‐dihydroxy‐ent‐kauran‐19‐oic acid ( 1 ), together with eight known analogues 2 – 9 were isolated from the aerial parts of Wedelia prostrata. One of the acidic diterpenoids, kaurenoic acid ( 3 ), was converted to seven derivatives, 10 – 16 . All compounds were evaluated for their cytotoxic activity in vitro against human leukemia (K562), liver (HepG‐2), and stomach (SGC‐7901) cancer cell lines. Only four kaurenoic acid derivatives, 13 – 16 , with 15‐keto and substitutions at C(19) position, exhibited notable cytotoxic activities on these tumor cell lines with IC₅₀ value ranging from 0.05 to 3.71 μm . Compounds 10 – 12 , with oxime on C(15) showed moderate inhibitory effects and compounds 1 – 9 showed no cytotoxicities on them. Structure–activity relationships were also discussed based on the experimental data obtained. The known derivative, 15‐oxokaurenoic acid 4‐piperdin‐1‐ylbutyl ester ( 17 ), induced typical apoptotic cell death in colon SW480 cells upon evaluation of the apoptosis‐inducing activity by flow‐cytometric analysis.     

Three new cytochalasins from the marine-derived fungus Spicaria elegans KLA03 by supplementing the cultures with L- and D-tryptophan

Three new cytochalasins Z₂₁–Z₂₃ ( 1 – 3 , resp.), together with five analogs, 4 – 8 , were isolated from Spicaria elegans KLA03 by the OSMAC (one strain‐many compounds) approach with adding L ‐ and D ‐tryptophan during its cultivation. The structures of new cytochalasins were elucidated on the basis of comprehensive 1D‐ and 2D‐NMR and HR‐ESI‐MS analyses. Cytochalasins Z₂₁ and Z₂₂ ( 1 and 2 , resp.), and compound 5 showed cytotoxic activities against A‐549 cell lines with IC₅₀ values of 8.2, 20.0, and 3.1 μM , respectively.     

Iridoids from Pedicularis verticillata and Their Anti‐Complementary Activity

Three new iridoids named as pediverticilatasin A – C ( 1 – 3 , resp.), together with five known iridoids ( 4 – 8 , resp.) were isolated from the whole plants of Pedicularis verticillata. The structures of three new compounds were identified as (1S,7R)‐1‐ethoxy‐1,5,6,7‐tetrahydro‐7‐hydroxy‐7‐methylcyclopenta[c]pyran‐4(3H)‐one ( 1 ), (1S,4aS,7R,7aS)‐1‐ethoxy‐1,4a,5,6,7,7a‐hexahydro‐7‐hydroxy‐7‐methylcyclopenta[c]pyran‐4‐carboxylic acid ( 2 ), (1S,4aS,7R,7aS)‐1‐ethoxy‐1,4a,5,6,7,7a‐hexahydro‐7‐hydroxy‐7‐methylcyclopenta[c]pyran‐4‐carbaldehyde ( 3 ). Their structures were elucidated on the basis of spectroscopic methods and compared with the NMR spectra data in the literature. All compounds were evaluated for their anti‐complementary activity on the classical pathway of the complement system in vitro. Among which, compounds 1 , 3 , and 6 exhibited anti‐complementary effects with CH₅₀ values ranging from 0.43 to 1.72 mm , which are plausible candidates for developing potent anti‐complementary agents.