A new bioactive steroidal ketone from the South China Sea sponge Xestospongia testudinaria

A new steroidal ketone (1), with an ergosta-22,25-diene side chain, was obtained from the South China Sea marine sponge Xestospongia testudinaria. The structure of 1 was determined on the basis of detailed spectroscopic analysis and by comparison with literature. Compound 1 exhibited significant inhibitory activity against protein tyrosine phosphatase 1B (PTP1B), a key target for the treatment of type II diabetes and obesity, with an IC₅₀ value of 4.27 ± 0.55 μM, which is comparable with the positive control oleanolic acid (IC₅₀ = 2.63 ± 0.22 μM).     

Brominated polyunsaturated lipids with protein tyrosine phosphatase-1B inhibitory activity from Chinese marine sponge Xestospongia testudinaria

A new brominated polyunsaturated lipid, methyl (E,E)-14,14-dibromo-4,6,13-tetradecatrienoate (1), along with three known related analogues (2–4), were isolated from the Et₂O-soluble portion of the acetone extract of Chinese marine sponge Xestospongia testudinaria treated with diazomethane. The structure of the new compound was elucidated by detailed spectroscopic analysis and by comparison with literature data. Compound 3 exhibited significant inhibitory activity against protein tyrosine phosphatase 1B (PTP1B), a key target for the treatment of type II diabetes and obesity, with an IC₅₀ value of 5.30 ± 0.61 μM, when compared to the positive control oleanolic acid (IC₅₀ = 2.39 ± 0.26 μM).     

Two new sesquiterpenoid glycosides from the leaves of Lycium barbarum

Two new sesquiterpenoid glycosides, lyciumionosides A–B (1–2), together with four known compounds (3–6), were isolated from the leaves of Lycium barbarum. Their structures were mainly established on the basis of MS, 1D and 2D NMR spectroscopic techniques. The antiproliferative activities of compounds 1–5 were evaluated. Compound 1 showed highest inhibitory activity against A549 cells with IC₅₀ value of 32.6 ± 2.6 μM, compound 3 showed highest inhibitory activity against PC-3 cells with IC₅₀ value of 36.0 ± 2.9 μM, and compound 5 exhibited highest inhibitory activity against HeLa cells with IC₅₀ value of 32.3 ± 4.2 μM.     

Rhobupcyanoside B,A new cyanoside from Rhodiola bupleuroides

One new cyanoside, rhobupcyanoside B (1), together with 7 known ones, was isolated from the 70% ethanol extract of the roots and rhizomes of Rhodiola bupleuroides. Their structures were determined by spectroscopic methods, including 2D NMR techniques. Compound 1 was evaluated for its inhibitory activity against α-glucosidase with IC₅₀ value of 278.28 ± 0.55 μM by comparing with the positive control (acarbose) at 210.40 ± 0.32 μM.     

Cladosporamide A,a new protein tyrosine phosphatase 1B inhibitor,produced by an Indonesian marine sponge-derived Cladosporium sp.

Cladosporamide A (1), a new protein tyrosine phosphatase (PTP) 1B inhibitor, was isolated together with a known prenylated flavanone derivative (2) from the culture broth of an Indonesian marine sponge-derived Cladosporium sp. TPU1507 by solvent extraction, ODS column chromatography, and preparative HPLC (ODS). The structure of 1 was elucidated based on 1D and 2D NMR data. Compound 1 modestly inhibited PTP1B and T-cell PTP (TCPTP) activities with IC₅₀ values of 48 and 54 μM, respectively. The inhibitory activity of 2 against PTP1B (IC₅₀ = 11 μM) was approximately 2-fold stronger than that against TCPTP (IC₅₀ = 27 μM).

     

Two new sesquiterpenoids from cultures of the basidiomycete Tremella foliacea

Two new sesquiterpenoids, trefoliol B (1) and trefoliol C (2), together with known echinocidin A (3), were isolated from cultures of the basidiomycetes Tremella foliacea. The new structures were elucidated on the basis of extensive spectroscopic methods. At the same time, trefoliol B (1) and echinocidin A (3) were tested for their cytotoxicities against five human cancer cell lines and for their inhibitory activities against isozymes of 11β-hydroxysteroid dehydrogenases (11β-HSD). No compound showed significant activity (IC₅₀ > 40 μM). Compound 1 showed moderate inhibitory activities against 11β-HSD1 (human IC₅₀ = 13.1 μM; mouse IC₅₀ = 91.8 μM).     

Selective cytotoxic eremophilane-type sesquiterpenes from Penicillium citreonigrum

Abstract

One new eremophilane-type sesquiterpene (1, citreopenin) was isolated from Penicillium citreonigrum (HQ738282), and the structure was elucidated by a combination of spectroscopic data interpretation and single-crystal X-ray diffraction analysis using Cu Kα radiation (CCDC 1030588). Compound 1 showed weak activity against KB-VIN (IC₅₀ = 11.0 ± 0.156 μM), while the known compound 3 exhibited selective cytotoxicity against MDA-MB-231 triple-negative breast cancer (TNBC) (IC₅₀ = 5.42 ± 0.167 μM).     

Further brominated polyacetylenes with pancreatic lipase inhibitory activity from Chinese marine sponge Xestospongia testudinaria

A new brominated polyacetylene, xestonariene I (1), along with three known related analogues (2–4), was obtained from Chinese marine sponge Xestospongia testudinaria. Its structure was determined on the basis of detailed spectroscopic analysis and by comparison with literature data. Compound 4 exhibited significant inhibitory activity against pancreatic lipase, which plays a key role in preventing obesity, with an IC₅₀ value of 0.61 μM, being comparable to that of the positive control orlistat (IC₅₀ = 0.78 μM).     

Steroid glycosides from the starfish Pentaceraster gracilis

Using combined chromatographic separations, two new steroid glycosides namely pentacerosides A (1) and B (2), and four known compounds were isolated from the methanol extract of the starfish Pentaceraster gracilis. Their structures were determined on the basis of spectroscopic data (¹H and ¹³C NMR, HSQC, HMBC, ¹H-¹H COSY, ROESY, and FT-ICR-MS) and by comparing obtained results to the literature values. Among the isolated compounds, only maculatoside (5) showed significant cytotoxic effect against Hep-G2 (IC₅₀ = 16.75 ± 0.69 μM) and SK-Mel2 (IC₅₀ = 19.44 ± 1.45 μM) cell lines and moderate effect on KB (IC₅₀ = 36.53 ± 0.78 μM), LNCaP (IC₅₀ = 39.75 ± 3.34 μM), and MCF7 (IC₅₀ = 47.34 ± 7.01 μM) cell lines.     

Two new triterpenes from Euphorbia alatavica

A phytochemical investigation on Euphorbia alatavica Boiss resulted in the isolation of nine compounds, including two new ones, alatavolide and alatavoic acid (1–2). Chemical structures of these compounds were established on the basis of 1D, 2D NMR, and HR-MS techniques, and by comparison with data reported in the literature. Compounds 1, 2, 4, 6, 8, and 9 were screened for cytotoxicity using the MTT assay. Among these compounds, the new compound 2 showed moderate cytotoxicity against Hela, MCF-7 and A549 cell lines (IC₅₀ values of 16.4 ± 3.2, 14.5 ± 2.8, 22.3 ± 3.1 μM, respectively), while the known compound 8 exhibited the most potent cytotoxicity with the IC₅₀ values of 6.5 ± 3.1, 1.9 ± 0.9, 8.6 ± 3.5 μM, respectively.     

New polyacetylenes glycoside from Eclipta prostrate with DGAT inhibitory activity

One new polyacetylene glycoside eprostrata Ⅰ (1), together with seven known compounds (2–8), were isolated from Eclipta prostrata. Their structures were elucidated on the basis of spectroscopic and physico-chemical analyses. All the isolates were evaluated inhibitory activity on DGAT in an in vitro assay. Compounds 1–8 were found to exhibit inhibitory activity of DGAT1 with IC₅₀ values ranging from 74.4 ± 1.3 to 101.1 ± 1.1 μM.     

Anti-inflammatory and antimicrobial coumarins from the stems of Eurya chinensis

Two new coumarins, named (±)-euryacoumarin A (1) and 6-demethylobtusinin (2), and one new natural coumarin, named euryacoumarin B (3), along with two known compounds, scopoletin (4) and obtusinol (5), were isolated from the stems of Eurya chinensis. Their structures were elucidated by means of extensive spectroscopic methods and comparison with data reported in the literatures. Compound 1 exhibited significant inhibition of LPS-induced nitric oxide (NO) production in RAW264.7 cells with IC₅₀ value of 35.64 ± 1.73 μM, and showed marginal antibacterial activities against Bacillus subtilis and B. cereus with MIC values of 50.59 ± 2.12 and 35.42 ± 0.96 μM, respectively.     

Six new C-21 steroidal glycosides from Dregea sinensis Hemsl

Six new C-21 steroidal glycosides (1–6) were separated from the root of Dregea sinensis Hemsl. and their structures were elucidated using extensive nuclear magnetic resonance, mass spectrometry, and infrared spectral analyses. Isolated compounds were evaluated for antitumor activity, which showed that compound 3 had moderate activity in Jurkat cells (IC₅₀ 19.54 ± 0.91 μM), and compounds 1–4 had significant effects against IL-2R and TNFR2 (IC₅₀ 1.518 ± 0.06 μM to 5.9 ± 0.07 μM).     

Cytotoxic triterpene saponins from Clematis mandshurica

Two new triterpene saponins, mandshunosides A and B (1 and 2), were isolated from the roots and rhizomes of Clematis mandshurica. Their structures were elucidated on the basis of spectroscopic evidence and hydrolysis products. Compounds 1 and 2 showed inhibitory activities against two colorectal human cancer cells HCT 116 (IC₅₀ 2.1 μM for 1 and 2.5 μM for 2) and HT-29 (IC₅₀ 3.7 μM for 1 and 3.3 μM for 2).     

Six new diterpenoids from Croton laevigatus

Abstract

Six new ent-labdane-type diterpeniods (1?6), along with one known compound, were identified from the twigs and leaves of Croton laevigatus. Their structures were elucidated on the basis of extensive spectroscopic interpretation. Compounds 2 and 7 showed inhibitory activity against protein tyrosine phosphatase 1B (PTP1B) with IC₅₀ values of 4.11 and 8.33 μg/ml, respectively.     

Steroid constituents from the soft coral Sinularia microspiculata

A methanol extract of the soft coral Sinularia microspiculata revealed five sterols, including two new compounds. Using combined chromatographic and spectroscopic experiments, the new compounds were found to be 7-oxogorgosterol (1) and 16α-hydroxysarcosterol (2). Their structures were determined on the basis of spectroscopic data (¹H and ¹³C NMR, HSQC, HMBC, ¹H-¹H COSY, NOESY, and FT-ICR-MS) and by comparing obtained results to the values indicated in previous studies. Among the isolated compounds, 3 showed weak cytotoxic effects against HL-60 (IC_50? = 89.02 ± 9.93?μM) cell line, whereas 5 was weakly active against HL-60 (IC_50? = 82.80 ± 13.65?μM) and SK-Mel2 (IC_50? = 72.32 ± 1.30?μM) cell lines.     

Furanone derivative and sesquiterpene from Antarctic marine-derived fungus Penicillium sp. S-1-18

Abstract

A new furanone derivative, butanolide A (1), and a new sesquiterpene, guignarderemophilane F (2), together with six known compounds, were isolated from the fungus Penicillium sp. S-1-18 derived from Antarctic marine. The new structures were determined by spectroscopic studies such as 1D- and 2D-NMR and MS analyses. The absolute configuration of 1 was determined by the modified Mosher’s method, while the absolute configuration of 2 was determined by calculated ECD spectroscopy. The isolated secondary metabolites were evaluated for their protein tyrosine phosphatase 1B (PTP1B) inhibitory activity. Compound 1 showed moderate inhibitory activity against PTP1B with IC₅₀ value of 27.4 μM.     

New triterpenoids with protein tyrosine phosphatase 1B inhibition from Cedrela odorata

Two new apotirucallane-type triterpenoids, cedrodorols A–B (1 and 2), along with seven known compounds (3–9), were isolated from the twigs and leaves of Cedrela odorata. Their structures were elucidated on the basis of extensive spectroscopic analysis. Compounds 1 and 2 showed significant inhibitory activity against protein tyrosine phosphatase 1B (PTP1B) with the IC₅₀ values of 13.09 and 3.93 μg/ml, respectively.     

Selective dual cholinesterase inhibitors from Aconitum laeve

New lycoctonine-type dual cholinesterase inhibitor, swatinine-C (1), along with three known norditerpenoid alkaloids, hohenackerine (2), aconorine (5) and lappaconitine (6) and two synthetically known but phytochemically new benzene derivatives, methyl 2-acetamidobenzoate (3) and methyl 4-[2-(methoxycarbonyl)anilino]-4-oxobutanoate (4), was isolated from the roots of A. laeve. Structures of new and known compounds (1–6) were established on the basis of latest spectroscopic techniques and by close comparison with the data available in literature. In vitro, compounds (1–6) were tested against AChE and BChE inhibitory activities. Compounds 1 and 2 showed competitive inhibition against AChE (IC_50?=?3.7 μM, 4.53 μM) and BChE (IC_50?=?12.23 μM, 9.94 μM), respectively. Compounds 5 and 6 showed promising noncompetitive type of inhibitory profile against AChE (IC_50?=?2.51 and 6.13 μM) only. Compounds 3 and 4 showed weak inhibitory profile against both AChE and BChE.     

Two pairs of rare naturally occurring 4-hydroxy-4-methyl-2,5-heptanedione derivatives from the red alga Chondria crassicaulis

Two pairs of rare naturally occurring racemic lipids, (±)-4,7-dihydroxy-4-methyl-2,5-heptanedione (1), and (±)-7-butoxy-4-hydroxy-4-methyl-2,5-heptanedione (2) were isolated from the red alga Chondria crassicaulis Harv. The structures of the racemic mixtures of 1 and 2 were elucidated by detailed spectroscopic techniques, including 1D and 2D NMR (¹H and ¹³C NMR, ¹H–¹H COSY, HSQC, and HMBC) as well as mass spectrometry and optical rotation experiments, and by comparison with data for related known analogs. This is the first report of naturally occurring 4-hydroxy-4-methyl-2,5-heptanedione derivatives. Antifungal, PTP1B inhibitory, and receptor tyrosine kinase inhibitory activities of these two compounds were investigated. The results showed that compounds 1 and 2 exhibited good selective inhibition against RET tyrosine kinase activity with IC₅₀ values of 9.56 and 8.93 μM, respectively. Compound 1 also displayed moderate antifungal activity against Cryptococcus neoformans (32609), showing a MIC₈₀ value of 32 μg/ml.