Carapanolides C–I from the seeds of andiroba (Carapa guianensis,Meliaceae)

Five new mexicanolide-type limonoids, carapanolides C–G (1–5), together with two new phragmalin-type limonoids, carapanolides H–I (6, 7), were isolated from the oil of Carapa guianasis AUBLET (Meliaceae) seeds. Their structures were elucidated on the basis of spectroscopic analyses using 1D and 2D NMR spectra and FABMS. Carapanolides C (1), E (3), and I (7) exhibited moderate activity in the P388 (IC₅₀ 17.9 μM in 1, 15.8 μM in 3) and L1210 cell lines (IC₅₀ 13.3 μM in 1, 18.1 μM in 3, 16.9 μM in 7). On the other hand, Carapanolide D (2) exhibited a strong inhibitory effect in the HL-60 cell line (IC₅₀ 11.0 μM), Carapanolides F (4) showed inhibitory activity in the L1210 cell line (IC₅₀ 15.9 μM), and the cytotoxic activity of Carapanolides I (7) was moderate in all cell lines.     

Sesquiterpene coumarin and sesquiterpene chromone derivatives from Ferula ferulaeoides (Steud.) Korov.

Five novel compounds — three sesquiterpene coumarin derivatives, ferulin A (1), B (2), and C (3), and two sesquiterpene chromone derivatives, ferulin D (4) and E (5), together with eleven known compounds (6–16) have been isolated from the roots of Ferula ferulaeoides (Steud.) Korov. Their structures were established by comprehensive spectroscopic analysis. The biosynthetic pathways leading to these compounds were proposed. The cytotoxicity of all these isolates against HepG2, MCF-7, and C6 cancer cell lines was evaluated and compound 7 displayed the highest potency against HepG2, MCF-7, and C6 with IC₅₀ values 39.9 μM, 37.7 μM, and 16.0 μM, respectively.     

New α-glucosidase inhibitors with p-terphenyl skeleton from the mushroom Hydnellum concrescens

The purpose of this study is to elucidate the bioactive components responsible for the the α-glucosidase inhibitory activity detected in the EtOAc extract of the mushroom Hydnellum concrescens. Two new p-terphenyl derivatives, concrescenins A (1) and B (2), in along with six known compounds thelephantins L (3), I (4), J (5), K (6), dihydroauran-tiacin dibenzoate (7), and curtisian A (8) were isolated from the fruiting bodies of H. concrescens. Their chemical structures were elucidated by NMR experiments. Compounds 1–4 and 6–8 showed the inhibitory activity against α-glucosidase with the IC₅₀ of 0.99, 3.11, 4.53, 18.77, 2.98, 5.16, and 8.34 μM, respectively. Kinetic analysis of α-glucosidase indicated that compounds 1 and 2 inhibited the activity of α-glucosidase in a noncompetitive fashion with a Ki value of 0.02 and 0.21 μM, respectively. In antioxidant evaluation, compounds 1 and 4 showed weak DPPH scavenging activity (EC₅₀ = 82.50 and 161.75 μM) and weak reducing ability (EC₅₀ = 193.57 and 152.94 μM). The current research supports the potential use of mushroom-derived p-terphenyl derivatives for the treatment of diabetes.     

New cytotoxic compounds from flowers of Lawsonia inermis L.

Three new compounds, a bicoumarin A (1), a biflavonoid A (2), and a biquinone A (3), as well as 12 other known compounds, were isolated from the flower of Lawsonia inermis L. The structures were elucidated by spectral analysis and new compounds 2 and 3 then were further confirmed by ECD calculations and single-crystal X-ray diffraction crystallography respectively. The cytotoxicity of the compounds against four cancer cell lines, including MCF-7, Hela, HCT-116, and HT-29 were evaluated using MTT assay. The IC₅₀ values of compounds 3 and 5 against MCF-7, Hela, HCT-116, and HT-29 were 2.24, 1.42, 24.29, and 7.02 μM and 6.1, 2.44, 5.58, and 10.21 μM respectively. The two compounds exhibited stronger inhibitory activities than the positive control 5-fluorouracil (IC₅₀ = 7.34, 11.50, 36.17, 18.83 μM) against the four tested cell lines. These results demonstrated that compounds from the flowers of L. inermis L. showed cytotoxic activity on MCF-7, Hela, HCT-116, and HT-29 cell lines.     

Cleistanthane diterpenes from the seed of Caesalpinia sappan and their antiausterity activity against PANC-1 human pancreatic cancer cell line

Three new cleistanthane diterpenes named tomocinon (1), tomocinol A (2), and tomocinol B (3), were isolated from the EtOAc extract of the seed of Caesalpinia sappan. Their structures were determined by extensive NMR spectroscopic analysis. The absolute stereochemistry of tomocinon (1) has been established by CD spectroscopic analysis. Cleistanthane diterpenes (1–3) represents the novel class of antiausterity agents having preferential cytotoxicity against PANC-1 human pancreatic cancer cell line under nutrient deprived condition with PC₅₀ value of 34.7 μM, 42.4 μM and 39.4 μM, respectively.     

Isolation,characterization and acetylcholinesterase inhibitory activity of alkaloids from roots of Stemona sessilifolia

Two new alkaloids, named stenine A (1) and stenine B (2), along with the known compounds neostenine (3), stenine (4) and neotuberostemonine (5), were isolated from the roots of Stemona sessilifolia. Their structures were elucidated by 1D- and 2D-NMR spectra and X-ray single-crystal diffraction experiment. Anti-acetylcholinesterase (AChE) activity of compounds 1–5 were also tested. Compounds 2 and 4 showed significant anti-acetylcholinesterase activities, with IC₅₀ values of 2.1 ± 0.2 μM and 19.8 ± 2.5 μM, resp. The mode of AChE inhibition by Compound 2 (the most potential AChE inhibitor) was reversible and competitive. In addition, molecular modeling was performed to explore the binding mode of compound 2 with AChE.     

Cyclodepsipeptides from the ascocarps and insect-body portions of fungus Cordyceps cicadae

A new cyclodepsipeptide cordycecin A (1), together with four known ones beauvericin E (2), beauvericin J (3), beauvericin (4), and beauvericin A (5) was isolated from the ascocarps and insect-body portions of fungus Cordyceps cicadae. Their structures were identified by NMR and MS analyses. The absolute configuration of 1 was confirmed by crystal X-ray diffraction. Compounds 2–5 exhibited a significant inhibitory effect on HepG2 and HepG2/ADM cells with IC₅₀ values ranging from 2.40 ± 0.37 to 14.48 ± 1.68 μM. Interestingly, compounds 3–5 showed cytotoxic activity against multiple drug resistant HepG2 cell line (HepG2/ADM) with IC₅₀ value 25-fold more sensitive to doxorubicin.     

Sesquiterpenes from the rhizomes of Alpinia japonica and their inhibitory effects on nitric oxide production

A novel norsesquiterpene (1), three new bisabolenes sesquiterpenes (2–4), along with 7 known compounds (5–11), were isolated from the rhizomes of Alpinia japonica. The structures of the new compounds were elucidated by analysis of spectroscopic data. The absolute configuration of C-1 in 3 was deduced via the circular dichroism data of the in situ formed [Rh₂(OCOCF₃)₄] complexes. Inhibitory effects of the isolates on nitric oxide production in lipopolysaccaride-activated RAW264.7 macrophages were evaluated. Compound 6 showed significant inhibitory activity with IC₅₀ value of 5.3 μΜ, and compounds 1, 3, 5 and 7–10 exhibited moderate inhibitory activities with IC₅₀ values between 24.5 and 46.3 μM.     

α-Glucosidase inhibitory triterpenoids from the stem barks of Uncaria laevigata

A phytochemical study on the ethanolic extract of the stem barks of Uncaria laevigata leads to the isolation and characterization of 18 triterpenoid compounds. Ten of these are new, including one novel heptanortriterpenoid (1), four ursane triterpenes (2–4, 10), and five oleanane triterpenes (5–9). Their structures were established by spectroscopic methods, especially by 2D-NMR and MS analyses. All these isolates were evaluated for their inhibitory effects on α-glucosidase: ursolic acid and 3 showed potent activities with IC₅₀ values of 16 ± 2.2 and 49 ± 3.7 μM, respectively.     

Desmodeleganine,a new alkaloid from the leaves of Desmodium elegans as a potential monoamine oxidase inhibitor

Desmodeleganine (1), a new potential monoamine oxidase inhibitor, along with three known alkaloids, bufotenin (2), hydroxy-N, N-dimethyltryptamine N¹²-oxide (3), 2-(5-methoxy-1H-indol-3-yl)-N, and N-dimethylethylamine (4) were isolated from the leaves of Desmodium elegans. Their structures were elucidated by IR, MS, 1D and 2D NMR spectra. 1 showed strong monoamine oxidase inhibitory activity with IC₅₀ value of 13.92 ± 1.5 μM, when the IC₅₀ value of iproniazid as a standard was 6.5 ± 0.5 μM. The molecular modeling was also performed to explore the binding mode of compounds 1, 2 at the active site of MAO-A and MAO-B.     

Sibiricasaponins A–E,five new triterpenoid saponins from the aerial parts of Polygala sibirica L.

Five new triterpenoid saponins, named as sibiricasaponins A–E (1–5), were isolated and identified from the aerial parts of Polygala sibirica L., together with nine known triterpenoid saponins (6–14). The chemical structures of the five new triterpenoid saponins (1–5) were elucidated as 3β,19α-dihydroxyurso-12-ene-23,28-dioic acid 3-O-β-d-glucuronopyranoside (1), pomolic acid 3-O-(3-O-sulfo)-α-l-arabinopyranoside (2), pomolic acid 3-O-(4-O-sulfo)-β-d-xylopyranoside (3), pomolic acid 3-O-(2-O-acetyl-3-O-sulfo)-α-l-arabinopyranoside (4), and 3-O-β-d-glucopyranosyl medicagenic acid 28-O-β-d-galactopyranosyl (1 → 4)-β-d-xylopyranosyl (1 → 4)-α-l-rhamnopyranosyl (1 → 2)-(4-O-acetyl)-[β-d-apiofuranosyl (1 → 3)]-β-d-fucopyranosyl ester (5), respectively, on the basis of spectroscopic data and physicochemical evidences. These isolated compounds (1–14) were evaluated for their anti-ischemic effects on oxygen/glucose deprivation (OGD) model in vitro, and only compound 7 showed a weak anti-ischemia effect, with EC₅₀ value of 46.7 μM.     

Polyacetylenes and anti-hepatitis B virus active constituents from Artemisia capillaris

Three new polyacetylenes, 8-(Z)-decene-4, 6-diyne-1, 3, 10-triol (1), 1, 3S, 8S-trihydroxydec-9-en-4, 6-yne (2), 3S, 8S-dihydroxydec-9-en-4, 6-yne 1-O-β -D-glucopyranoside (3), and one new glucosyl caffeoate, 1-O-ethyl-6-O-caffeoyl-β -D-glucopyranose (4), together with 34 known compounds were isolated from Artemisia capillaris. The structures of the new compounds were determined by extensive spectroscopic analyses including 1D and 2D NMR, HRESIMS, [α]_D and CD experiments. Among them, 19 compounds showed activity inhibiting HBsAg secretion; 20 compounds showed activity inhibiting HBeAg secretion; and 25 compounds possessed inhibitory activity against HBV DNA replication according to our anti-HBV assay on HepG 2.2.15 cell line in vitro. The most active compound 12 could inhibit not only the secretions of HBsAg and HBeAg, but also HBV DNA replication with IC₅₀ values of 15.02 μM (SI = 111.3), 9.00 μM (SI = 185.9) and 12.01 μM (SI = 139.2).     

8-9′ linked neolignans with cytotoxicity from Alpinia conchigera

Five new 8-9′ linked neolignans conchigeranals A–E (1–5), together with three known compounds galanganal (6), galanganols A (7) and B (8), were isolated from the whole plant of Alpinia conchigera. Their structures were established by spectroscopic analysis, including 2D-NMR spectroscopic techniques. Cytotoxicities of compounds 1–8 were tested against two cancer cell lines A549 and Hela. Results showed that 4, 5, 7 and 8 exhibited cytotoxicity against A549 with the IC₅₀ values of 12.36, 9.72, 10.26, 13.05 μg/ml, respectively, and 1–8 against Hela with the IC₅₀ values from 1.53 to 5.29 μg/ml.     

Andirolides Q–V from the flower of andiroba (Carapa guianensis,Meliaceae)

Two new gedunins, an andirobin, two mexicanolides, and a phragmalin-type limonoid, named Andirolides Q (1), R (2), S (3), T (4), U (5), and V (6), were isolated from an oil of the flower of Carapa guianensis AUBLET (Meliaceae). Their structures have been elucidated on the basis of spectroscopic analyses using 1D and 2D NMR spectra and FABMS. Andirolide S (3) and Andirolide T (4) showed significant cytotoxic activity against the murine P388 leukemia cell line (IC₅₀ of 1.4 μM for 3; 1.8 μM for 4) and the human HL-60 leukemia cell line (IC₅₀ of 1.3 μM for 3 and 4).     

Biotransformation on the flavonolignan constituents of Silybi Fructus by an intestinal bacterial strain Eubacterium limosum ZL-II

Eubacterium limosum ZL-II is an anaerobic bacterium with demethylated activity, which was isolated from human intestinal bacteria in our previous work. In this study, the flavonolignan constituents of Silybi Fructus were biotransformed by E. limosum¹ ZL-II, producing four new transformation products — demethylisosilybin B (T1), demethylisosilybin A (T2), demethylsilybin B (T3) and demethylsilybin A (T4), among which T1 and T2 were new compounds. Their chemical structures were identified by ESI-TOF/MS, ¹H NMR, ¹³C NMR, HMBC and CD spectroscopic data. The bioassay results showed that the transformation products T1–T4 exhibited significant inhibitory activities on Alzheimer's amyloid-β 42 (Aβ₄₂²) aggregation with IC₅₀ values at 7.49 μM–10.46 μM, which were comparable with that of the positive control (epigallocatechin gallate, EGCG³, at 9.01 μM) and much lower than those of their parent compounds (at not less than 145.10 μM). The method of biotransformation by E. limosum ZL-II explored a way to develop the new and active lead compounds in Alzheimer's disease from Silybi Fructus. However, the transformation products T1–T4 exhibited decreased inhibitory activities against human tumor cell lines comparing with their parent compounds.     

Cycloartane Triterpenes from Beesia calthaefolia (Maxim.)

Three new cycloartane triterpenoids (1–3) and two known compounds (4, 5) were isolated from the whole plant of Beesia calthaefolia. Their structures were elucidated by 1D and 2D NMR, HRESIMS and optical rotation spectral data. All isolates were investigated for their inhibitory effects on the classical pathway of the complement system. Among them, compound 4 showed stronger inhibitory activity (IC₅₀ 136.7 μM) than positive control (Rosmarinic acid, IC₅₀ 181.8 μM) while compounds 2 and 3 were moderately active with IC₅₀ value of 206 μM and 200.9 μM. Chemical compound studied in this article: Rosmarinic acid (PubChem CID: 5281792).     

Triterpenoids of sour jujube show pronounced inhibitory effect on human tumor cells and antioxidant activity

Sour jujube is a common fruit and traditional medicine in China. Bioactivity-guided fractionation of sour jujube was used to determine the chemical identity of potent antiproliferative and antioxidant constituents. Four novel ursane-type triterpenoids, together with 8 known were isolated and identified. The new triterpenoids were elucidated to be 2α,3β,13β,23-tetrahydroxy-urs-11-en-28-oic acid (3), 2α,3β-dihydroxy-urs-20(30)-en-28-oic acid (9), 2α,3β,28-trihydroxy-urs-20(30)-ene (10), and 3β,12β,13β-trihydroxy-ursan-28-oic acid (11). Among the triterpenoids isolated, 2α,3β,19α-trihydroxy-urs-12-en-28-oic acid (7), 9 and 10 showed high potent inhibitory activity toward the proliferation of HepG2 cells, which the IC₅₀ values were lower than 5 μM. Compounds 9 and 10 also exhibited pronounced activity against MCF-7 cells, with IC₅₀ value of 0.8 ± 0.03 and 1.5 ± 0.1 μM, respectively. Compound 10 showed high antioxidant activity with an EC₅₀ of 0.8 ± 0.02 μM, which was 18.9 times higher than ascorbic acid in antioxidant capacity.     

Japonicasins A and B,two new isoprenylated flavanones from Sophora japonica

Two new flavanones with a C₁₅ isoprenoid group, japonicasins A and B (1 and 2), were isolated from the leaves of Sophora japonica. This is the first report on the presence of the (2E,7E)-6-isopropyl-3,9-dimethyldeca-2,7,9-trien-1-yl group (C₁₅ isoprenoid group) in isoprenylated flavonoids. Their structures were determined by spectroscopic methods, including UV, IR, 1D and 2D NMR, HRESIMS, and CD experiments. In addition, the antioxidant activities of compounds 1 and 2 were determined through DPPH radical scavenging assays. They exhibited potential antioxidant activities, with IC₅₀ values of 35.1 ± 0.8 μM and 88.7 ± 1.1 μM for compounds 1 and 2, respectively.     

A potent acetylcholinesterase inhibitor from Pancratium illyricum L.

Plants belonging to the Amaryllidaceae contain an exclusive group of alkaloids, known as sources of important biological activities. In the present work, Pancratium illyricum L., a species belonging to this family and endemic of Sardinia (Italy), was investigated for its alkaloid content. Fresh bulbs and leaves were processed separately. Standard extraction and purification procedures were applied to obtain fractions and compounds for GC–MS and NMR analysis. In addition to eight already known alkaloids (1–8), 11α-hydroxy-O-methylleucotamine (9) was isolated for the first time and its structure completely determined by one and two-dimensional ¹H and ¹³C NMR spectroscopy. This new galanthamine-type compound exhibited a pronounced in vitro acetylcholinesterase (AChE) inhibitory activity (IC₅₀ = 3.5 ± 1.1 μM) in comparison to the reference standard galanthamine hydrobromide (IC₅₀ = 1.5 ± 0.2 μM).     

Novel NGF-potentiating limonoids from the fruits of Melia toosendan

Four new limonoids (1–4), together with five known limonoids (5–9), were isolated from the fruits of Melia toosendan. Their structures were elucidated based on extensive spectroscopic analyses (1D- and 2D-NMR, HRESIMS, IR, [α]_D). The isolated compounds were evaluated for their neurite outgrowth-promoting activities. Compounds 2 and 6 significantly enhanced NGF-mediated neurite outgrowth in PC12 cells at concentrations ranging from 0.1 to 50.0 μM.