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.     

New Pterosin Sesquiterpenes and Antitubercular Constituents from Pteris ensiformis

Two new pterosin sesquiterpenes, (2S)‐13‐hydroxypterosin A ( 1 ) and (2S,3S)‐12‐hydroxypterosin Q ( 2 ), were isolated from the whole plants of Pteris ensiformis, together with six known compounds. The structures of 1 and 2 were determined through extensive 1D/2D‐NMR and MS analyses. Compound 2 exhibited antitubercular activity (MIC 6.25 μg/ml) against Mycobacterium tuberculosis H₃₇Rv in vitro.     

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.     

Antiviral activity of Distictella elongata (Vahl) Urb. (Bignoniaceae), a potentially useful source of anti-dengue drugs from the state of Minas Gerais, Brazil

Aims: To investigate the in vitro antiviral activity of Distictella elongata (Vahl) Urb. ethanol extracts from leaves (LEE), fruits (FEE), stems and their main components. Methods and Results: The antiviral activity was evaluated against human herpesvirus type 1 (HSV‐1), murine encephalomyocarditis virus (EMCV), vaccinia virus Western Reserve (VACV‐WR) and dengue virus 2 (DENV‐2) by the 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) colorimetric assay. LEE presented anti‐HSV‐1 [EC₅₀ 142·8 ± 5·3 μg ml^?1; selectivity index (SI) 2·0] and anti‐DENV‐2 activity (EC₅₀ 9·8 ± 1·3 μg ml^?1; SI 1·5). The pectolinarin ( 1 ) isolated from LEE was less active against HSV‐1 and DENV‐2. A mixture of the triterpenoids ursolic, pomolic and oleanolic acids was also obtained. Ursolic and oleanolic acids have shown antiviral activity against HSV‐1. A mixture of pectolinarin ( 1 ) and acacetin‐7‐O‐rutinoside ( 2 ) was isolated from FEE and has presented anti‐DENV‐2 activity (EC₅₀ 11·1 ± 1·6 μg ml^?1; SI > 45). Besides the antiviral activity, D. elongata has disclosed antioxidant effect. Conclusions: These data shows that D. elongata has antiviral activity mainly against HSV‐1 and DENV‐2, besides antioxidant activity. These effects might be principally attributed to flavonoids isolated. Significance and Impact of the Study: Distictella elongata might be considered a promising source of anti‐dengue fever phytochemicals.     

Three New Constituents with Anti-Inflammatory and Antimicrobial Activities in Vitro from the Roots of Capsicum annuum L.

Three new compounds, including two new sesquiterpenes ( 1–2 ), named Annuumine E−F, and one new natural product, 3-hydroxy-2,6-dimethylbenzenemethanol ( 3 ), together with seventeen known compounds ( 4–20 ) were isolated from the ethanol extract of the roots of Capsicum annuum L. Among them, five compounds ( 4 , 5 , 9 , 10 and 20 ) were isolated from this plant for the first time. The structures of new compounds ( 1–3 ) were determined via detailed analysis of the IR, HR-ESI-MS and 1D and 2D NMR spectra. The anti-inflammatory activities of the isolated compounds were evaluated by their ability to reduce NO release by LPS-induced RAW 264.7 cells. Notably, compound 11 exhibited moderate anti-inflammatory activity (IC₅₀=21.11 μM). Moreover, the antibacterial activities of the isolated compounds were also evaluated.     

Trichodermaloids A–C,Cadinane Sesquiterpenes from a Marine Sponge Symbiotic Trichoderma sp. SM16 Fungus

Three new cadinane sesquiterpenes, trichodermaloids A ( 1 ), B ( 2 ), and C ( 5 ) were isolated from a symbiotic fungus Trichoderma sp. SM16 derived from the marine sponge Dysidea sp., together with three known ones, aspergilloid G ( 3 ), rhinomilisin E ( 4 ), and rhinomilisin G ( 6 ). The complete structures of three new compounds were determined by HR‐MS and NMR spectroscopic analyses coupled with ECD calculations. The absolute configurations of two known compounds ( 4 and 6 ) were determined for the first time. The six isolates were inactive as antibacterial agents. However, trichodermaloids A and B have shown cytotoxicity on human NCIH‐460 lung, NCIC‐H929 myeloma, and SW620 colorectal cancer cell lines with IC₅₀ values at the range of 6.8–12.7 μm .     

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 .     

Repraesentins D,E and F,New Plant Growth Promoters from Lactarius repraesentaneus

Three new plant growth regulatory sesquiterpenes were isolated from the Lactarius repraesentaneus fungus. Their structures were elucidated to be lactarane sesquiterpenes, namely repraesentins D (1) and E (2), and a protoilludane-related sesquiterpene, namely repraesentin F (3). Repraesentin E (2) showed the strongest promotion activity, 164% at 3.6 μM, of the three compounds toward the radicle elongation of lettuce seedlings.     

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.     

Guaiane-Type Sesquiterpenes from the Stems of Fissistigma oldhamii

Two new guaiane-type sesquiterpenes dysodensiols J and L, one new natural product dysodensiol K together with four known biogenetically related guaiane-type sesquiterpenes were isolated from the stems of Fissistigma oldhamii. Their structures were elucidated by detailed analysis of NMR, HR-ESI-MS, IR and Optical rotations data. Compound 1 contains an uncommon five-membered ether ring. The inhibitory effect of all compounds on the proliferation of primary synovial cells was evaluated. Compound 3 showed inhibitory activity with an IC₅₀ value of 6.8 μM. Compounds 5–7 exhibited moderate inhibitory activity with IC₅₀ values of 23.8, 26.6, and 27.1 μM, respectively.     

Halogenated Metabolites Isolated from Penicillium citreonigrum

Three chromone analogs, 1 – 3 , a chlorinated alkaloid sclerotioramine ( 4 ), together with two 11‐noreremophilane‐type sesquiterpenes with a conjugated enolic OH group and a brominated one, 5 and 6 , respectively, were isolated from Penicillium citreonigrum (HQ738282). Compounds 1, 5 , and 6 were new. Biological tests revealed that 4 exhibited a significant activity (IC₅₀ 7.32 μg/ml), and 6 showed a moderate activity (IC₅₀ 16.31 μg/ml) in vitro against HepG2 cell line, and 4 also displayed an activity comparable to that of acarbose against α‐glucosidase.     

Melanogenesis Inhibitors from the Endophytic Fungus Aspergillus amstelodami

Two new compounds, named 3,4‐dimethoxyphenyl α‐d ‐ribofuranoside ( 1 ) and 3β‐(β‐d ‐glucopyranosyloxy)olean‐12‐ene‐23,28,30‐trioic acid ( 2 ), together with thirteen known compounds, were isolated from the white beans culture of the marine derived endophytic fungus Aspergillus amstelodami. Structure elucidation of the new compounds was carried out by one‐, two‐dimensional spectroscopy, and high resolution electrospray ionization mass. The antimelanogenic and anti‐allergic activity of the isolated compounds were investigated. Compounds 4 , 7 , 1 , 3 , 11 , 6 and 9 selectively suppressed melanin production in B16 melanoma cells, using arbutin as a positive control. Their IC₅₀ values were 30.8±5.57, 38.5±6.08, 52.6±6.64, 98.0±1.16, 100.4±3.05, 112.0±0.22 and 144.7±2.35 μm , respectively, while that of arbutin was 151.7±1.27 μm . The tested compounds did not show any significant anti‐allergic activity in RBL‐2H3 cells, as compared to quercetin.     

Superbanone,A New 2‐Aryl‐3‐benzofuranone and Other Bioactive Constituents from the Tube Roots of Butea superba

Phytochemical investigation from the tube roots of Butea superba, led to the isolation and identification of a new 2‐aryl‐3‐benzofuranone named superbanone ( 1 ), one benzoin, 2‐hydroxy‐1‐(2‐hydroxy‐4‐methoxyphenyl)‐2‐(4‐methoxyphenyl)ethanone ( 2 ), eight pterocarpans ( 3  –  10 ), and eleven isoflavonoids ( 11  –  21 ). Compound 2 was identified for the first time as a natural product. The structure of the isolated compounds was elucidated using spectroscopic methods, mainly 1D‐ and 2D‐NMR. The isolated compounds and their derivatives were evaluated for α‐glucosidase inhibitory and antimalarial activities. Compounds 3 , 7 , 8 , and 11 showed promising α‐glucosidase inhibitory activity (IC₅₀ = 13.71 ± 0.54, 23.54 ± 0.75, 28.83 ± 1.02, and 12.35 ± 0.36 μm , respectively). Compounds 3 and 11 were twofold less active than the standard drug acarbose (IC₅₀ = 6.54 ± 0.04 μm ). None of the tested compounds was found to be active against Plasmodium falciparum strain 94. On the basis of biological activity results, structure–activity relationships are discussed.     

Two new lignans and anti-HBV constituents from Illicium henryi

Two new lignans, dihydrodehydrodiconiferyl alcohol 9‐O‐β‐D ‐(3″‐O‐acetyl)‐xylopyranoside ( 1 ) and threo‐4,9,9′‐trihydroxy‐3,3′‐dimethoxy‐8‐O‐4′‐neolignan 7‐O‐α‐rhamnopyranoside ( 2 ) were isolated from Illicium henryi, together with ten known compounds, 3 – 12 . Their structures were elucidated by extensive spectroscopic analyses. The anti‐hepatitis B virus (anti‐HBV) activity of compounds 1 – 12 inhibiting HBV surface antigen (HBsAg) and HBV e antigen (HBeAg) secretion on Hep G2.2.15 cell line was evaluated. (−)‐Dihydrodehydrodiconiferyl alcohol ( 4 ) showed moderate inhibitory activity on both HBsAg and HBeAg secretion with IC₅₀ values of 0.06 and 0.53 mM , respectively.     

Five Sesquiterpenes from Paraconiothyrium sp. and Their Anti-inflammatory Activity

Five eremophilane sesquiterpenes including three new ones, named paraconions A–C ( 1 – 3 ), were isolated from an endophytic fungus, Paraconiothyrium sp. from Artemisia selengensis. The structures of these new compounds were established based on spectroscopic methods, including nuclear magnetic resonance (NMR), ultraviolet (UV), and infrared (IR) spectroscopy, as well as high resolution electrospray ionization mass spectrometry (HR-ESI-MS). An anti-inflammatory assay indicated that paraconion B ( 2 ) inhibited lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 cells, with an IC₅₀ value of 51.7 μM. The compounds discovered in this study will enrich the structural types of secondary metabolites of the endophytic fungus Paraconiothyrium sp.     

Sesquiterpenoids from Chloranthus henryi and Their Anti‐neuroinflammatory Activities

Five new and seven known mono‐sesquiterpenoids ( 1 – 5 and 6 – 12 , resp.) together with five known lindenane‐type disesquiterpenoids, 13 – 17 , were isolated from the whole plant of Chloranthus henryi. Based on spectroscopic methods, the new structures were established to be (5S,6R,8S,10R)‐6‐hydroxyeudesma‐4(15),7(11)‐diene‐12,8‐olide ( 1 ), 6α‐hydroxyeudesma‐4(15),7(11),8(9)‐triene‐12,8‐olide ( 2 ), 8,12‐epoxy‐1β‐hydroxyeudesma‐4(15),7,11‐trien‐6‐one ( 3 ), 12‐oxochloraniolide A ( 4 ), and (4α)‐8‐hydroxy‐12‐norcardina‐6,8,10‐trien‐11‐one ( 5 ), respectively. Among the isolates, compound 2 , zederone epoxide ( 8 ), spicachlorantin G ( 13 ), chloramultilide A ( 14 ), shizukaol B ( 15 ), and spicachlorantin B ( 17 ) showed significant anti‐neuroinflammatory effects by inhibiting nitric‐oxide (NO) production in lipopolysaccharide (LPS)‐stimulated murine BV‐2 microglial cells with relatively low cytotoxicity.     

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 ).     

A New Anti‐Inflammatory Alkaloid from Roots of Heracleum dissectum

Using various chromatographic methods, a new piperidinone alkaloid, (3S)‐3‐{4‐[(1E)‐3‐hydroxyprop‐1‐en‐1‐yl]‐2‐methoxyphenoxy}piperidin‐2‐one ( 1 ), together with 10 known compounds, bergapten ( 2 ), xanthotoxol ( 3 ), isopimpinellin ( 4 ), isobergapten ( 5 ), heratomol‐6‐O‐β‐d ‐glucopyranoside ( 6 ), scopoletin ( 7 ), apterin ( 8 ), 3‐methoxy‐4‐β‐d ‐glucopyranosyloxypropiophenone, (praeroside; 9 ), tachioside ( 10 ) and coniferin ( 11 ), were isolated from roots of Heracleum dissectum Ledeb . Their structures were elucidated on the basis of physicochemical properties and the detailed interpretation of various spectroscopic data. All the isolated compounds were screened for anti‐inflammatory activity in vitro. As the results, compound 1 and 8 showed significantly inhibitory activity on nitric oxide production in RAW264.7 cells.     

New Guaiane-Type Sesquiterpene and Norsesquiterpene from Alisma plantago-aquatica and Their Xanthine Oxidase Inhibitory Activity

A new sesquiterpene ( 1 ) and a new norsesquiterpene ( 2 ) belonging guaiane-type skeleton together with six known compounds ( 3 – 8 ) were isolated from the rhizomes of Alisma plantago-aquatica. Their structures were determined by HR-ESI-MS, 1D and 2D NMR spectroscopic methods. Absolute configurations of new compounds were established by experimental and TD-DFT computational ECD spectra. Compounds 1 – 8 exhibited xanthine oxidase inhibitory activity with their IC₅₀ values in range of 9.4–66.7 μM. The sesquiterpenoids 1 – 5 displayed the inhibitory activity and hence they could be potential xanthine oxidase inhibitors from A. plantago-aquatica.     

Chemical Composition and Antimicrobial Activity of Ageratina deltoidea

The chemical study of Ageratina deltoidea afforded grandiflorenic acid ( 1 ), ent‐kaurenoic acid ( 2 ), and eight benzylbenzoates ( 3  –  10 ), two of them, 3,5‐dimethoxybenzyl 2,3,6‐trimethoxybenzoate ( 5 ) and 4‐(β‐d ‐glucopyranosyloxy)‐3‐hydroxybenzyl 2,6‐dimethoxybenzoate ( 9 ), described for the first time. In addition, the new sesquiterpene lactone deltoidin C ( 13 ), together with the known 11 and 12 , the phenolic compounds: ayanin, 2,6‐dimethoxybenzoic acid, methyl 3,4‐dihydroxycinnamate, chlorogenic acid, and 3,5‐dicaffeoylquinic acid were also isolated. The structures of these compounds were determined by spectroscopic methods and chemical reactions. The antibacterial and antifungal activities of compounds 1  –  12 were evaluated on Staphylococcus aureus, Escherichia coli, and Candida albicans. Deltoidin A ( 11 ) was the most active antibacterial agent (MIC 16.0 μg ml^?1) against E. coli, and the ent‐kaurenoid derivatives ( 1  –  2 ) showed activity (MIC 31.0 μg ml^?1) against S. aureus.