Honatisine, a novel diterpenoid alkaloid, and six known alkaloids from Delphinium honanense and their cytotoxic activity

A novel diterpene alkaloid named honatisine (1) has been isolated from the whole plants of Delphinium honanense, along with six known alkaloids, siwanine E (2), isoatisine (3), atisine (4), delcorinine (5), uraphine (6), and nordhagenine A (7). Their structures were deduced on the basis of their spectral data. All of them were evaluated by a SRB assay for their cytotoxicity, and compound 1 showed a significant cytotoxic activity (IC(50) =3.16 μM) against the MCF-7 cell line.     

Pregnane alkaloids from Sarcococca ruscifolia and their cytotoxic activity

Six pregnane alkaloids were isolated from the root of Sarcococca ruscifolia. The structures of three new alkaloids, namely, sarcorucinine E–G (1–3), were elucidated using spectroscopic methods, while three known alkaloids, namely, epipachysamine D, pachysamine M, and sarcovagine D, were identified by comparing their spectral data with those of the compounds reported earlier. All compounds were evaluated for their inhibitory activities against multiple types of cancer cells.     

Three new compounds isolated from the bulbs of Fritillaria pallidiflora Schrenk and their anti-inflammatory activity

Three new compounds, 17β-cevanin-6-oxo-5α,20β-diol yibeinine (1), 2-(tetrahydro-5-(2-hydroxyphenyl)-2H-pyran-3-yl) phenol (2), 1,3-O-diferuloyl-2-methoxypropane diol (3), as well as four known compounds (4–7), have been isolated from the ethanol extract of dried bulbs of Fritillaria pallidiflora Schrenk. All structures were determined based on their spectroscopic data (1D and 2D NMR (including ¹H NMR, ¹³C NMR, ¹H-¹H COSY, HMBC, HSQC, HSQC-TOCSY, and NOESY experiments), and MS). Biological evaluation showed that compounds 1–4 inhibited the production of nitric oxide (NO) in LPS-stimulated RAW 264.7 cells with IC₅₀ values of 18.0, 38.7, 29.5, and 47.1 μM, respectively. These results indicated that compound 1 has potential anti-inflammatory activity.     

Pyranones from kiwi-associated fungus Fusarium tricinctum and their antibacterial activity

Four new pyrone derivatives, fusaritricins A–D (1−4), together with five known analogues, were obtained from the kiwi endophytic fungus Fusarium tricinctum. Their structures were established by extensive spectroscopic data analysis and their absolute configurations were determined by quantum chemical calculations. Compounds 1, 2, 3, and 9 exhibited antibacterial activity against plant pathogen Pseudomonas syringae pv. Actinidiae (Psa) with MIC values of 128, 128, 64, and 64 µg/mL, respectively. This is the first report of anti-Psa activity of pyrone derivatives.     

Two new alkaloids with carboxylic acid moieties from Portulaca oleracea and their anti-inflammatory effects

Two new alkaloids with carboxyl, identified as 8-(6,7-dihydroxy-1,2,3,4-tetrahydroisoquinolin-1-yl) octanoic acid and 5-(diethylamino)-2-(3-(diethylamino)-3-oxopropyl)-2-hydroxy-5-oxopentanoic acid named oleralkacid A and oleralkacid B, were isolated from Portulaca oleracea L. for the first time, whose structures were determined using spectroscopic methods including ¹D NMR, ²D NMR, UHPLC-ESI-QTOF/MS and circular dichroism (CD). Subsequently, the anti-inflammatory effects of compounds on lipopolysaccharide-stimulated macrophages were studied, and the results showed that the compound 1 and 2 at 5 μM and 10 μM could significantly inhibit inflammatory mediator IL-1β, respectively.     

Benzophenanthridine alkaloids from Zanthoxylum nitidum (Roxb.) DC, and their analgesic and anti-inflammatory activities

Seven benzophenanthridine alkaloids, 1-7, were isolated from the roots of Zanthoxylum nitidum. Among them, two novel alkaloids, named (R)-8-[(R)-1-hydroxyethyl]dihydrochelerythrine (1) and 8-methoxynorchelerythrine (2), were structurally identified as new compounds on the basis of the spectroscopic analysis. Bioactivity evaluation showed that nitidine (3), dihydrochelerythrine (4), oxyavicine (5), 8-methoxychelerythrine (6), and 8-hydroxydihydrochelerythrine (7) exhibit comparable analgesic and anti-inflammatory effects as hydrocortisone.     

Two new alkaloids from Asparagus stipularis Forssk. roots

Two new alkaloids, aspastipuline (1) and 5-hydroxyaspastipuline (2) were isolated from Asparagus stipularis Forssk. roots. Their structures were elucidated by spectroscopic techniques (1D and 2D NMR, HREIMS). The absolute structure of 2 was established by single-crystal X-ray diffraction analysis. Aspastipuline exhibited a moderate antiproliferative activity against the human mammary gland adenocarcinoma cell line MCF-7.     

Two new antibacterial sesquiterpenoids from Centipeda minima

Two new guaiane-type sesquiterpene lactones, compounds 1 and 2, along with three known guaianolide- or pseudoguaianolides, were isolated from Centipeda minima (whole plant). Their structures were identified by spectroscopic and mass-spectrometric analyses. The configuration at C5 of the guaiane framework of 1 was rationalized by quantum-mechanical calculations (Table 2). All compounds were found to be active against eight different microbial pathogens (Table 3), with MIC values in the range of 6.25-100 microg/ml.     

Two new alkaloids from Brachystemma calycinum and their inhibitory effects on lymphocyte proliferation

Two new alkaloids, brachystemidines F (1) and G (2), were isolated from the roots of Brachystemma calycinum. Their structures were established on the basis of detailed spectroscopic analyses, including extensive NMR and HR-MS techniques. Compound 2, which exhibits an unusual N-hydroxydiazenyl (HO-N=N) moiety, is a potent immunosuppressive agent, as demonstrated by inhibition of mouse T- and B-lymphocyte proliferation, with IC50 values of 6.33 and 5.60 microg/ml, resp.     

Antibacterial activity against drug-resistant microbial pathogens of cytochalasan alkaloids from the arthropod-associated fungus Chaetomium globosum TW1-1

By feeding 1-methyl-l-tryptophan (1-MT) into cultures of the arthropod-associated fungus Chaetomium globosum TW1-1, three novel cytochalasan alkaloids, termed as armochaetoglosins A–C (1–3), together with five known analogues, namely prochaetoglobosin I (4), chaetoglobosin T (5), chaetoglobosin C (6), armochaetoglobin Y (7), and chaetoglobosin V_b (8), were isolated and characterized. Their structures including absolute configurations were elucidated by means of NMR spectroscopy, single-crystal X-ray crystallography, and comparison of the experimental electronic circular dichroism (ECD) spectra. Structurally, compounds 1–3 represented the first examples of 1′-N-methyl-chaetoglobosins, which were possibly biosynthesized from the additive 1-MT rather than tryptophan. Additionally, compound 3 showed the highest antibacterial activity against K. pneumoniae and ESBL-E. coli with MIC values of 4.0 μg/mL and 16.0 μg/mL, respectively, wherein the inhibitory effect of 3 against K. pneumoniae was stronger than that of the clinically used antibiotic meropenem, with an MIC value of 8 μg/mL. Our findings may provide new chemical templates for the development of new antibacterial agents against drug-resistant microbial pathogens.     

富贵草杀灭钉螺效应研究

以富贵草(Pachysandra terminalis Sieb.et Zucc.)(以下简称PT)为实验材料,采用开放式浸杀法研究其植物原粉及提取物(PT-Ⅰ)对钉螺的杀灭效果和对鱼类的毒性作用。结果表明PT原粉浓度为17.5 mg/L时,钉螺72 h死亡率为93.4%,120 h死亡率达100.0%;其24、72、120、168 h的LC50分别为42.28、7.20、4.20、3.17 mg/L。PT原粉浓度为75.0 mg/L时,经168 h鱼死亡率为0。使用浓度为35.0、17.5、8.75、4.38 mg/L的PT原粉,分别浸泡1、2、18、42 h时,抑制钉螺上爬率均达到100%。原粉经提取分离得到PT-Ⅰ组分,以1.40 mg/L的PT-Ⅰ组分分别浸杀钉螺24、48、72、96、120 h,钉螺死亡率分别为36.7%、73.3%、96.7%、96.7%、100.0%。表明PT具有很好的杀灭钉螺、抑制钉螺上爬效果,且对鱼毒性较低,是一种较有研究价值的灭螺植物。     

Cytotoxic alkaloids from the bulbs of Fritillaria hupehensis

Phytochemical investigation of the bulbs of Fritillaria hupehensis resulted in the isolation and structural elucidation of four new steroidal penta- and hexacyclic veratraman- and cevan-based alkaloids, respectively, compounds 1-4. They were obtained together with the known constituents ebeinine (5) and zhebeinine (6), which were isolated for the first time from this plant. The structures of the new isolates were established by spectroscopic and mass-spectrometric analyses, in combination with chemical methods. All compounds were assayed for their cytotoxic effects towards HeLa and HepG2 cell lines. Compounds 1 and 2 showed significant inhibitory effects against both types of tumor cells, with IC(50) values in the range 2.52-0.23 microM, similar as those for 5-fluorouracil used as positive control.     

四数九里香中的咔唑类生物碱成分及其细胞毒活性研究

为阐明民族药四数九里香Murraya tetramera Huang的药效物质基础,本研究使用色谱分离技术从其醇提取物中分离纯化得7个咔唑类生物碱和1个甾体类化合物,运用波谱方法鉴定为β-谷甾醇(1)、1-甲基-3-丙酰基咔唑(2)、1-甲氧基-3-乙基咔唑(3)、1-甲氧基-3-甲酰基咔唑(4)、1-甲氧基-3-甲基咔唑(5)、1-羧基甲酯-3-甲基咔唑(6)、1-羧基甲酯-3-乙基咔唑(7)、mananimbine(8)。除了化合物1,其他化合物为首次从该植物中分离得到;化合物2～5、7对SMMC-7721的IC50分别为40. 93±0. 66、46. 03±2. 05、114. 21±5. 67、15. 79±0. 99、185. 1±0. 44。结果表明化合物2～5、7对SMMC-7721显现很好的细胞毒活性。     

Two new imidazolone-containing alkaloids and further metabolites from the ascomycete fungus Tricladium sp

Tricladins A and B (1 and 2, resp.), new imidazolone-containing alkaloids, together with five known metabolites, bacillamides A, B (3 and 4, resp.), 20-hydroxyaflavinine (5), N-(2-phenylethyl)acetamide (6), and N(b)-acetyltryptamine (7), have been isolated from the crude extract of the ascomycete fungus Tricladium sp. The structures of 1 and 2 were elucidated primarily by NMR and MS methods. Compound 2 showed marginal cytotoxicity against MDA-MB-231 human breast cancer cells, whereas the known metabolite 4 displayed an inhibitory effect on HIV-1 replication in C8166 cells.     

Two new aporphine alkaloids with glucose consumption increasing activity from Cassytha filiformis

Two new aporphine alkaloids, named precassythine (1) and (+)− 6S-ocotecine-N-oxide (2), were isolated from Cassytha filiformis. The new structures were elucidated by applying various spectroscopic techniques, including 1D-, ²D NMR and HRESIMS. The absolute configurations of 1 and 2 were determined by calculated electronic circular dichroism (ECD). Both compounds were evaluated for their effects on glucose consumption on HL-7702 cells at different concentrations. The results showed that the two new compounds significantly increased glucose consumption.     

Pyrrolizidine alkaloids from Anchusa strigosa and their antifeedant activity

The pyrrolizidine alkaloid (PA) content of flowers, leaves, and roots of Anchusa strigosa (Boraginaceae) was analysed by ESI-LC-MS. Six PAs, including two new natural compounds, were detected, characterized by NMR spectroscopy, and quantified in each plant organ. The results indicated that the highest total concentration of PAs was in the leaves (23.63 mg/g of dried part), followed by the flowers (19.77 mg/g), and finally by the roots (1.80 mg/g). All PAs isolated were subjected to Spodoptera exigua and Pieris brassicae larvae. Feeding activity by both herbivore species using a bioassay was inhibited up to circa 75% depending on PA and applied concentration.     

Hexahydrobenzophenanthridine alkaloids from Corydalis bungeana Turcz. and their anti-inflammatory activity

As part of a bioprospecting program aimed at the discovery of anti-inflammatory agents from the Corydalis bungeana Turcz. (C. bungeana), five new hexahydrobenzophenanthridine alkaloids, corycaline A-E (1–5), along with four known alkaloids, were isolated from the whole plant of C. bungeana. Their structures including absolute configurations were elucidated on the basis of extensive spectroscopic analyses and electronic circular dichroism (ECD) calculations. The inhibitory activities of the nine compounds on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 mouse macrophage cells were determined; all tested compounds except 2 and 7 exhibited significant inhibitory effects with IC₅₀ values in the range of 1.00–2.79?μM.     

Cyclopeptide alkaloids from Scutia buxifolia Reiss and their antimicrobial activity

The present study reports a cyclopeptide alkaloid, scutianine M, isolated from the methanolic root bark extract of Scutia buxifolia Reiss (Rhamnaceae) along with six known compounds, scutianines-B, -C, -D, -E, -F, and scutianene D. Its structure was established on the basis of spectroscopic analyses, including application of 2D NMR spectroscopic techniques. As part of a study of the bioactive compounds of medicinal plants from southern Brazil, we also compared the antimicrobial activity of the isolated compounds towards Gram (+), Gram (-) bacteria, and yeasts.     

Taxonomic significance and antitumor activity of alkaloids from Clausena lansium Lour. Skeels (Rutaceae)

Phytochemical analysis of isolates from the aerial parts of Clausena lansium Lour. Skeels (Rutaceae) led to the identification of 14 alkaloids, including two indole alkaloids (1 and 2), one quinoline alkaloid (3), two pyridine alkaloids (4 and 5), four carbazole alkaloids (6–9) and five amides alkaloids (10–14). The phytochemical structures of the alkaloids were established by means of NMR and MS spectral analyses. Compounds (4, 5, 14) were three new natural products, while 1–3 and 10 were firstly reported from the genus Clausena and 8 and 9 were isolated from this species for the first time. The chemotaxonomic significance of these isolated alkaloids has also been discussed. All the isolated alkaloids were tested for their cytotoxic activity against Hela cancer cell line. Among them, four carbazole alkaloids 6–9 exhibited weak cytotoxicity with IC₅₀ values ranging from 69.31 to 138.32 μM.     

Pentacyclic triterpenoids and other constituents isolated from the leaves of Gambeya lacourtiana and their antibacterial activity

The phytochemical study was done on the leaves of Gambeya lacourtiana. This plant has been used in traditional medicine to treat of different ailments such as uterine heamorrhage, metritis and other vaginal infections. Chromatographic fractionation and purification on the leaves crude extract afforded lupeol acetate (1), lupenone (2), lupeol (3), taraxerol (4) stigmasterol (5), erythrodiol (6), chamaedrydiol (7), methyl pheophorbide-a (8), corosolic acid (9), tormentic acid (10), epicatechin (11) and 22-dihydrospinasterol 3-O-β-D-glucopyranoside (12). The structures of compounds 1–12 were elucidated on the basis of 1D and 2D NMR, mass spectrometric and the spectroscopic data as well as comparison with the literature. Compounds 4, 7–10 and 12 were isolated for the first time from Gambeya genus. Crude extract, fractions and compounds 6–12 were evaluated for their antibacterial activity. Methyl pheophorbide-a (8) demonstrated moderate activity against Salmonella typhi CPC with MIC values of 62.5 μg/mL. The chemophenetic significance of these compounds is also discussed.