Antihyperglycemic activity of phenylpropanoyl esters of catechol glycoside and its dimers from Dodecadenia grandiflora

Bioactivity-guided separation of an antihyperglycemic extract from the leaves of Dodecadenia grandiflora afforded two phenylpropanoyl esters of catechol glycosides (1 and 4) and two lignane bis(catecol glycoside)esters (2 and 3). Their structures were established on the basis of extensive spectroscopic analysis (1D and 2D-NMR, MS). Compounds 2 and 3 are believed to be derived from dimerization via the two phenylpropanoid units of 1. Compounds 1–4 showed significant antihyperglycemic activity in streptozotocin-induced (STZ) diabetic rats, which is comparable to the standard drug metformin. Our results provide support to explain the use of D. grandiflora as antihyperglycemic agent by the traditional medical practitioners.     

Inhibitory Effects of Maleimide Derivatives from the Mycelia of the Fungus Antrodia cinnamomea BCRC 36799 on Nitric Oxide Production in Lipopolysaccharide (LPS)‐Activated RAW264.7 Macrophages

Four new maleimide derivatives, antrocinnamomins E–H ( 1 – 4 , resp.), together with (3S,4R)‐1‐hydroxy‐3‐(4‐hydroxyphenyl)‐4‐(2‐methylpropyl)pyrrolidine‐2,5‐dione ( 5 ) and ergosterol were isolated from the mycelia of Antrodia cinnamomea BCRC 36799. The structures were elucidated by 1D‐ and 2D‐NMR spectroscopy, and mass spectrometry. Compounds 1 – 5 were evaluated for their inhibitory effects on nitric oxide (NO) production by macrophages. Compounds 2 and 4 showed stronger inhibition of NO production than the positive control quercetin.     

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, 3β-acetoxy-24-methyllanosta-8,16,24(31)-trien-21-oic acid ( 3 ) and 3β-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 ¹H-, ¹³C-, 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.     

Naphthalene Derivatives and Quinones from Ventilago denticulata and Their Nitric Oxide Radical Scavenging,Antioxidant, Cytotoxic,Antibacterial, and Phosphodiesterase Inhibitory Activities

New naphthalene derivatives ( 1 and 2 ) and a new isomer ( 3 ) of ventilagolin, together with known anthraquinones, chrysophanol ( 4 ), physcion or emodin 3‐methyl ether ( 5 ), and emodin ( 6 ), were isolated from vines of Ventilago denticulata. The isolated compounds exhibited cytotoxic activity with IC₅₀ values of 1.15 – 40.54 μg/ml. Compounds 1 – 3 selectively exhibited weak antibacterial activity (MIC values of 200.0 – 400.0 μg/ml), while emodin ( 6 ) displayed moderate antibacterial activity with MIC value of 25.0 μg/ml. The isolated compounds showed nitric oxide and DPPH radical scavenging activities. Compounds 1 – 3 and 6 exhibited weak xanthine oxidase inhibitory activity, while emodin ( 6 ) acted as an aromatase inhibitor with the IC₅₀ value of 10.1 μm . Compounds 1 and 2 exhibited phosphodiesterase 5 inhibitory activity with IC₅₀ values of 8.28 μm and 6.48 μm , respectively.     

Three New Indole Diketopiperazine Alkaloids from Aspergillus ochraceus

Asperochramides A – D ( 1  –  4 ), a new natural product and three new indole diketopiperazine alkaloids, along with seven known analogs ( 5  –  11 ), were isolated from the ethyl acetate extract of Aspergillus ochraceus. Their structures were elucidated by extensive spectroscopic analyses, ECD calculation, and single‐crystal X‐ray diffraction analysis. Compounds 3 and 4 represent a rare group of indole diketopiperazine alkaloid with a 3‐hydroxyl‐2‐indolone moiety. The in vitro anti‐inflammatory effects of compounds 1 and 3  –  11 were investigated by using LPS‐stimulated murine macrophage RAW 264.7 cells. Compounds 1 , 8 , 10 , and 11 showed potential anti‐inflammatory activities.     

Daphnane‐Type Diterpenoid Glucosides and Further Constituents of Euphorbia pilosa

Phytochemical investigation of whole plants of Euphorbia pilosa led to the isolation and identification of two new daphnane‐diterpenoid glucosides, euphopilosides A and B ( 1 and 2 , resp.), and a new ent‐abietane, euphopilolide ( 3 ), together with eight known compounds. Compounds 1 and 2 are the first daphnane‐type diterpenoid glycosides. Their structures were elucidated by a combination of 1D‐ and 2D‐NMR, and MS analyses, and acid hydrolysis. Compounds 1 – 9 were evaluated for their in vitro cytotoxicities against five human tumor cell lines, HL‐60, SMMC‐7721, A‐549, MCF‐7, and SW‐480. Compound 7 showed moderate inhibitory activity against all five cell lines.     

New photoaffinity analogs of paclitaxel.

Two new photoreactive paclitaxel analogs bearing [3H2]-3-(4-benzoyl)phenylpropanoyl group as the photophore as well as radiolabeling unit at the 7 and 10 positions, respectively, are developed. These new photoreactive analogs showed excellent preliminary results on the photoaffinity labeling of tubulin and P-glycoprotein.     

Antibacterial Δ1‐3‐Ketosteroids from the South China Sea Gorgonian Coral Subergorgia rubra

Three new Δ¹‐3‐ketosteroids characterized with a 9‐OH, subergosterones A–C ( 1 – 3 ), together with five known analogs 4 – 8 , were obtained from the gorgonian coral Subergorgia rubra collected from the South China Sea. The structures of 1 – 3 , including their absolute configurations, were determined by comprehensive spectroscopic methods and electronic circular dichroism (ECD) experiments. Compounds 2 and 3 exhibited inhibitory antibacterial activities against Bacillus cereus with MIC values of 1.56 μM .     

Cyclohexenone Derivative and Drimane Sesquiterpenes from the Seagrass-Derived Fungus Aspergillus insuetus

One new cyclohexenone derivative ( 1 ), and two undescribed drimane sesquiterpenes ( 2 and 3 ), together with another seven known drimane sesquiterpenes were isolated from a seagrass-derived fungus Aspergillus insuetus SYSU6925. Structures of these metabolites were elucidated by comprehensive spectroscopic analysis, including NMR analysis, mass spectrometry, and ECD calculations. Compounds 1 – 3 , 5 and 7 displayed weak to moderate antifungal activities towards four phytopathogenic fungi, with Minimum inhibition concentration (MIC) values range from 50 to 200 μg/mL. Compound 1 , a rare cyclohexenone derivative with n-propyl group exhibited more potent inhibitory activities (MIC, 50 μg/mL) against F. oxysporum than positive control (Triadimefon). Compounds 2 and 3 also exhibit potent anti-inflammatory activities by inhibiting the production of nitric oxide (NO) in RAW264.7 cells with IC₅₀ values of 21.5±1.1 and 32.6±1.16 μM, respectively.     

Purpurides B and C,Two New Sesquiterpene Esters from the Aciduric Fungus Penicillium purpurogenum JS03‐21

Purpurides B and C ( 1 and 2 , resp.), two new sesquiterpene alcohol esters generated from a drimane‐type sesquiterpenoid lactone and an amino acid, together with two known analogs, berkedrimane B ( 3 ) and purpuride ( 4 ), were isolated from the aciduric fungus Penicillium purpurogenum JS03‐21. Their structures were elucidated by spectroscopic analysis, X‐ray single‐crystal diffraction, and application of Marfey's method. Compounds 1 – 4 showed modest antifungal activities against Candida albicans with MIC values in the range of 1.2–3.3 μM . Compounds 1 and 2 showed moderate antimicrobial activities against Enterobacter aerogenes and Pseudomonas aeruginosa with MIC values in the range of 1.2–2.6 μM .     

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.     

Three New Hydroxyphenylacetic Acid Derivatives and A New Alkaloid from Endophytic Fungus Mortierella sp. in Epimedium acuminatum Franch. and Their Antibacterial Activity

Three new hydroxyphenylacetic acid derivatives, stachylines E-G ( 1 – 3 ), and a new alkaloid, mortieridinone ( 4 ), along with six known compounds ( 5 – 10 ), were isolated from endophytic fungus Mortierella sp. in Epimedium acuminatum Franch. Their structures were determined by their spectroscopic analyses and by comparison with the literature data. Compounds 7 and 10 showed selective antibacterial activity against tested multidrug-resistant bacteria with minimum inhibitory concentration (MIC) values ranging from 25 to 3.13 μg/mL.     

Bioactive Coumarins from the Stems of Clausena emarginata

Five new coumarins, clauemarmarins I – M ( 1 – 4 ), together with 10 known analogs ( 5 – 14 ), were isolated from the stems of Clausena emarginata. Compounds 8 – 13 were obtained from this plant for the first time. Their structures were established and elucidated by comprehensive analysis of spectroscopic data. The absolute configurations of 1 – 4 were further determined by their electronic circular dichroism spectroscopy. Compounds 5 , 7 , 12 , and 14 exhibited inhibitory effects on LPS‐induced NO production. Compounds 5 – 7 showed selective neuroprotective effects in Aβ_{25 – 35} model at 10 μm .     

Triterpenoid Alkaloids from Buxus microphylla

Two new triterpenoid alkaloids, buxmicrophyllines J and K ( 1 and 2 , resp.), together with four analogues, 3 – 6 , were isolated from the leaves and stems of Buxus microphylla. The structures of the new compounds were elucidated by NMR and MS spectroscopic analyses. The partial assignments of the NMR spectra of 3 were also revised. Compounds 1 and 3 – 6 were evaluated for their growth inhibitory activity against human cell lines HL‐60, SMMC‐7721, A‐549, SK‐BR‐3, and PANC‐1. Compound 6 showed significant cytotoxicity against HL‐60, SK‐BR‐3, and PANC‐1 cell lines, with IC₅₀ values of 6.46, 19.61, and 28.57 μM , respectively.     

Two New Avermectin Derivatives from the Beibu Gulf Gorgonian Anthogorgia caerulea

Two new avermectin derivatives, avermectins B_1c and B_1e ( 1 and 2 , resp.), as well as two known compounds, avermectin B_2a ( 3 ) and ivermectin A_1a ( 4 ), were isolated from a Beibu Gulf gorgonian coral, Anthogorgia caerulea. The structures of the new compounds were established by detailed spectroscopic analysis and by comparison with spectral data of related known compounds. Compounds 1 – 4 showed moderate antifouling activities against the larval settlement of Balanus amphitrite.     

Neolignans and Sesquiterpenoid from Piper yunnanense

Two biphenyl-type neolignans with a rare dibenzofuran skeleton, including a new one piyunneolignan A ( 1 ) and a known one piperneolignan D ( 2 ), together with a new sesquiterpenoid piyunin A ( 3 ), were isolated from the leaves and twigs of Piper yunnanense. Their structures were established on the basis of comprehensive spectroscopic data analysis and electronic circular dichroism (ECD) calculation. Piyunneolignan A ( 1 ) featured a rare C-2−C-2′/C-3−O−C-3′ linkage. Compounds 1 – 3 were evaluated for their antimicrobial and cytotoxic activities against a panel of bacteria, fungi, and human cancer cell lines, respectively.     

Antifungal Bromophenols from Marine Red Alga Symphyocladia latiuscula

Three new highly brominated polyphenols, 1 – 3 , together with one known bromophenol, 4 , were isolated from the EtOH extract of a marine red alga Symphyocladia latiuscula collected from the coast of Qingdao, P. R. China. Their structures were identified by extensive spectroscopic experiments (NMR and MS) and comparison with literature data. Compounds 3 and 4 showed activities against the Candida albicans with the MIC values of 25 and 12.5 μg/ml, respectively.     

Two New Hydronaphthoquinones from Sinningia aggregata (Gesneriaceae) and Cytotoxic Activity of Aggregatin D

Two new hydronaphthoquinones, aggregatins E and F ( 1 and 2 , resp.) were isolated from the tubers of Sinningia aggregata (Ker‐Gawl .) Wiehler (Gesneriaceae), along with twelve known compounds aggregatin D ( 3 ), tectoquinone ( 4 ), 1‐hydroxy‐2‐methylanthraquinone ( 5 ), icosyl ferulate ( 6 ), pustuline ( 7 ), 1,6‐dihydroxy‐2‐methylanthranquinone ( 8 ), 6‐hydroxy‐2‐methylanthraquinone ( 9 ), 7‐hydroxy‐2‐methylanthraquinone ( 10 ), tyrosol ( 11 ), halleridone ( 12 ), calceolarioside B ( 13 ), and cornoside ( 14 ). All compounds were identified by analysis of spectroscopic and spectrometric data. Compounds 3, 4 , and 10 had already been reported in this species. Compounds 2 and 3 were evaluated against several tumor cell lines, but only 3 exhibited activities against UACC‐62, 786‐0 and OVCAR‐3 cell lines, with IC₅₀ values of 12.3, 12.8 and 0.3 μg/ml, respectively, without toxic effects on non‐cancer cell line HaCat (human keratinocyte).     

Withanolides from Physalin angulata and Their Inhibitory Effects on Nitric Oxide Production

Six new withanolides, angulasteroidins A−F ( 1 – 6 ), along with twelve known analogs ( 7-18 ) were isolated from the whole plants of Physalis angulata. Their structures were elucidated by analysis of 1D and 2D NMR, ECD and IR spectra, HR-ESI-MS data, and ECD calculation. Compounds 1 and 6 were rare 1–10 seco withanolides. Compounds 2 – 4 , 7 – 9 , and 15 exhibited significant inhibitory activity on the production of nitric oxide in the LPS-activated RAW 264.7 mouse macrophage cell lines with IC₅₀ values ranging from 0.23 to 9.06 μM.     

Biphenyl Derivatives from the Aerial Parts of Oenanthe javanica and Their COX‐2 Inhibitory Activities

Four new biphenyl derivatives ( 1 – 4 ), along with six known biphenyl derivatives ( 5 – 10 ) were isolated and elucidated by their detailed analyses of spectroscopic data and references from the aerial parts of Oenanthe javanica for the first time. Compounds ( 1 – 10 ) were assayed for their activities about the inhibition of COX‐2 enzyme in vitro for the first time. Compounds 1 , 2 , 4 , and 6 showed inhibitory activities against COX‐2 with IC₅₀ values ranging from 22.18±0.29 to 108.54±0.42 μm .