Nitric Oxide Inhibitory Activity Research Articles

(+)- and (–)-Corydecumbenines A and B, two pairs of novel quaternary protoberberine alkaloid cycloadduct enantiomers with anti-neuroinflammatory and neuroprotective activities from the rhizomes of Corydalis decumbens

Two novel Diels-Alder [4 + 2] cycloadducts of quaternary protoberberine alkaloids and fumaric acid monoanion, corydecumbenines A and B (1 and 2), and six known isoquinoline analogues (3–8) were isolated from the rhizomes of Corydalis decumbens. The planar structures of 1 and 2 were elucidated by extensive spectroscopic analysis including UV, IR, HRESIMS, 1D and 2D NMR. Chiral chromatography of 1 and 2 afforded two pairs of enantiomers (+)-corydecumbenine A (1a), (–)-corydecumbenine A (1b), (+)-corydecumbenine B (2a), and (–)-corydecumbenine B (2b), respectively, and their absolute configurations were determined by single-crystal X-ray crystallography and comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1b and 2b exhibited significant nitric oxide (NO) inhibitory activities in lipopolysaccharide (LPS)-stimulated BV-2 cells with IC50 values of 11.6 and 16.2 μM, respectively, comparable to the positive control indomethacin (IC50 = 10.3 μM), and they could also decrease the level of interleukin (IL)-1β in BV-2 cells in a dose-dependent manner. Most of the isolates showed neuroprotective effects against the injury of OGD/R-induced PC12 cells at 20 μM.

Metabolite Profiles of Red and White Rice Aqueous Extracts Derived at Different Temperatures and Their Relationship with Biological Properties as Determined Using 1H-NMR-Based Metabolomics Analysis

Consumption of pigmented rice has continued to increase in recent years, due in part to its potential health promoting properties, especially protection against chronic diseases. Chemical extracts of red rice have demonstrated strong ability to scavenge free radicals, however little is yet known about water extracts of red rice. The antioxidant activity, α-glucosidase inhibition, nitric oxide inhibition, and metabolic profiling of this cultivar’s water extracts have yet to be investigated. In this study, red rice and white rice were extracted using ultrasound-assisted hydrothermal extraction at three different temperatures. The total phenolic content (TPC) as well as the DPPH radical scavenging, α-glucosidase inhibitory, and nitric oxide (NO) inhibitory activities of each extract were determined. NMR analysis was performed to find out the metabolite profiles of the extracts. Correlations between the metabolites and the biological activities of the rice extracts were then investigated using metabolomics analysis. Results show that the red rice aqueous extracts had a higher TPC than the white rice extracts. The highest extraction temperature led to a decrease in the TPC. However, the extraction temperature did not affect the radical scavenging, α-glucosidase inhibitory, or NO inhibitory activities of the red rice extracts. The PCA results indicated extract discrimination by extraction temperature. The PLS score plot exhibited the potentials of red rice aqueous extracts on the α-glucosidase and NO inhibitory activities. The 1H-NMR-based metabolomics analysis shows that red rice aqueous extract possesses beneficial properties which can make it useful as an ingredient for functional foods or other products.

Structures and biological evaluation of phenylpropanoid derivatives from Dendrobium Sonia

Two new phenylpropanoid derivatives (1-2), together with eight known compounds (3-10) were isolated from the stems of Dendrobium sonia. The structures of these compounds were elucidated on the basis of spectroscopic analyses, including HRESIMS, 1 D and 2 D NMR experiments. All of the isolated compounds were tested for their Nitric Oxide (NO) Inhibitory Activities. The results of bioactive screening showed that compounds 2, 8, 9 and 10 exerted inhibitory effects on NO production with IC50 values in the range of 26.3 to 31.6 μM. Compound 8 and 9 exhibited stronger anti-inflammatory activities with IC50 values 26.3 and 27.7 μM, comparable to that of the positive control.

Antioxidant and antibacterial effects of medicinal plants and their stick-type medicinal concentrated beverages.

Nine medicinal plants and their stick-type medicinal concentrated beverages (SMCB-I and SMCB-II) with different combination ratio were evaluated on antioxidant, nitric oxide (NO) inhibitory, and antibacterial effects against pathogenic bacteria involved in respiratory system illnesses. Antioxidant activity was high in Syzygium aromaticum, Pueraria lobata, Plantago asiatica, and Kalopanax pictus which have higher contents of total phenolics and total flavonoids. The NO inhibitory activity was high in Syzygium aromaticum, Plantago asiatica, and Glycyrrhiza uralensis. Syzygium aromaticum, Plantago asiatica, Kalopanax pictus and Glycyrrhiza uralensis showed higher antibacterial activity than the other five medicinal plants against Staphylococcus aureus, Corynebacterium diphtheriae, and Mycobacterium sp. SMCB-II exhibited higher antioxidant, NO inhibitory, and antibacterial effects than SMCB-I, since Syzygium aromaticum, Pueraria lobata, and Kalopanax pictus were only used for the production of SMCB-II. The SMCBs would be expected to contribute to an easy-to-carry, easy-to-consume, and high value-added health beverage for the modern people.

Quassinoids and alkaloids from the stems of Picrasma quassioides with nitric oxide inhibitory activity

Two new quassinoids (picraquanines D and E, 1 and 2) and a new alkaloid (picraquanine F, 3), together with twelve known related compounds were obtained from the stems of Picrasma quassioides (D. Don) Benn. Their structures were elucidated on the basis of extensive spectroscopic techniques and chemical methods. The absolute configurations of 1 and 2 were determined by ECD experiments. Compound 10 showed nitric oxide (NO) inhibitory effects against LPS-stimulated RAW 264.7 cells with IC50 value of 96.1 μM.

Phenolic Contents, Comparative Antioxidant Studies and Anti-Tubercular Activities of Commonly Used Spices in Abuja, Nigeria

Spices are reported to be helpful against diseases of oxidative stress such as cardiovascular diseases and exhibit antimicrobial properties. The potential for their use in adjuvants in tuberculosis cases have not been explored. In this study, the in vitro antioxidant and anti-tuberculosis activities of nine Nigerian spices (Syzigium aromaticum, Thonnigii sanguinea, Piper nigrum, Zanthoxylum zanthoxyloides, Zingiber officinale, Cyperus articulatus, Xylopia aethiopica, Lepidum sativum, and Nigella Sativa) along with their phenolic contents, including total phenolics, total flavonoid, and total tannin contents were evaluated. Antioxidant activities were determined by DPPH scavenging and nitric oxide inhibitory assays. The anti-tuberculosis activity against Mycobacterium bovis and Mycobacterium smegmatis was evaluated using the broth micro-dilution method to determine the minimum inhibitory concentration (MIC). The ranges for the total phenolics, total flavonoids, and total tannins contents were 7.3-193.9 mg GAE/g, 0.0-12.5 mg QE/g, and 0.0-44.4 mg TAE/g, respectively, in all spices. The extracts presented strong DPPH scavenging and nitric oxide inhibitory activities with IC50 values ranging from 4.2-1098 µg/mL and 0.0025-28.65 µg/mL, respectively. S. aromaticum and T. sanguinea showed significant DPPH scavenging activities with IC50 of 4.2 and 7.7 µg/mL, respectively, which were comparable to that of ascorbic acid (3.6 µg/mL) (p ≤0.05). Z. zanthoxyloides and S. aromaticum also exhibited significant nitric oxide inhibitory activities (p ≤0.05) with IC50 of 0.0025 and 0.0051 µg/mL, respectively, which were comparable to the gallic acid value of 0.00088 µg/mL. A weak anti-tubercular activity was however observed with MIC values ranging from 25000-781 µg/mL and 12500-781 µg/mL for M. bovis and M. smegmatis, respectively. A correlation between anti-tubercular and antioxidant (NO and DPPH) activities of the spices was found for M. bovis and M. smegmatis (R =0.8957, 0.8241; R= 0.7681, 0.7030, p ≤ 0.05) respectively. The anti-tuberculosis properties of Thonnigii sanguinea and Lepidum sativum are being reported for the first time.

Anti-inflammatory canthin-6-one alkaloids from the roots of Thailand Eurycoma longifolia Jack.

Two new canthin-6-one alkaloids, 4,9-dimethoxy-5-hydroxycanthin-6-one (1) and 9-methoxy-(R/S)-5-(1-hydroxyethyl)-canthin-6-one (2), together with fifteen known ones were isolated from the roots of Thailand Eurycoma longifolia Jack. Among the known canthin-6-one alkaloids, compounds 9 and 16 were isolated from the Eurycoma genus for the first time. Meanwhile, the nitric oxide (NO) inhibitory activities of all isolates were examined in lipopolysaccharide (LPS)-stimulated RAW264.7 cells at 50µM. Moreover, a dose-dependent experiment was conducted for active compounds 1, 2, 4, 6, 7, 10, 12-17 at the concentration of 10, 25, and 50µM, respectively. Consequently, compounds 1, 4, 6, 7, 12, 14, 15, as well as 17 were found to inhibit NO release from RAW264.7 cells in a dose-dependent manner. Two new canthin-6-one alkaloids, 4,9-dimethoxy-5-hydroxycanthin-6-one (1) and 9-methoxy-(R/S)-5-(1-hydroxyethyl)-canthin-6-one (2), together with fifteen known ones were isolated from the roots of Thailand Eurycoma longifolia Jack. Among them, 1, 4, 6, 7, 12, 14, 15, as well as 17 were found to inhibit NO release from RAW264.7 cells in a dose-dependent manner at the concentration of 10, 25, and 50 µM.

New 20(S)-protopanaxadiol type saponins from the leaves of Panax notoginseng and their potential anti-inflammatory activities

Through the combination of various chromatographies, 11 new 20(S)-protopanaxadiol (PPD) type saponins, named as notoginsenosides NL-E1 − NL-E4 (1–4), NL-F1 (5), NL-F2 (6), NL-G1 (7), NL-G2 (8), NL-H1 − NL-H3 (9–11) were obtained from the leaves of Panax notoginseng. Their structures were ascertained based on the extensive spectroscopic methods and chemical reactions. Meanwhile, the 20(S)-PPD type saponins with aglycone, (20S,24ζ)-3β,12β,20,24,25-pentahydroxy dammarane, was only found from the leaves of P. notoginseng. The characteristic could be used to distinguish the extracts of P. notoginseng leaves from its other medicinal parts such as roots, rhizomes, flowers or seeds. Furthermore, the nitric oxide (NO) inhibitory activities of all compounds were examined in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. As a result, compounds 2–7, 10 could exert NO inhibitory activity at 25 μM without cytotoxicity. Moreover, the inhibitory activities of them were in dose-dependent manner at 1, 10, and 25 μM. Especially, notoginsenoside NL-F2 (6) still possessed strong biological activity at 1 μM.

Eucalyptus essential oils inhibit the lipopolysaccharide-induced inflammatory response in RAW264.7 macrophages through reducing MAPK and NF-\u03baB pathways

BackgroundEucalyptus essential oils have been used in traditional medicine for centuries. It was reported that Eucalyptus leaves possess antioxidant and antimicrobial effects. Here, we investigated the anti-inflammatory activity of the essential oils extracted from the leaves of four different Eucalyptus species in RAW264.7 macrophages.MethodsLipopolysaccharide (LPS)-activated RAW264.7 macrophages were used to evaluate the anti-inflammatory activity of the leaf essential oils of Eucalyptus. The cell survival was quantified by an Alamar Blue assay. Nitric oxide (NO) production was assessed by Griess reaction. TNF-α and IL-6 production were measured by enzyme-linked immunosorbent assay (ELISA). Nuclear factor-κB (NF-κB) transcriptional activity was measured by NF-κB reporter assay. Intracellular protein expression levels were determined by Western blot. The expression levels of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), mitogen-activated protein kinase (MAPK), protein kinase C (PKC) and NF-κB pathway were measured by western blot in LPS-activated RAW 264.7 macrophage.ResultsThe essential oils extracted from Eucalyptus citriodora leaf exert the best NO inhibitory activity in LPS-activated RAW264.7 macrophages. The essential oils were fractionated into fractions A-H, and fraction F has been demonstrated to inhibit the expression levels of TNF-α, IL-6, NO, iNOS and COX-2 in LPS-activated RAW264.7 macrophages. Mechanistic analysis revealed that fraction F reduced the phosphorylation levels of ERK1/2, p38, PKC-α, PKC-ε and PKC-δ, and inhibited the NF-κB transcriptional activity. The chemical composition of Fraction F was determined by GC-MS.ConclusionsThe discoveries made herein could help develop innovative nonsteroidal anti-inflammatory drugs with minimal side effects and strong efficacy. Clinical trials on these Eucalyptus leaf essential oils will help customize and optimize their therapeutic administration.

Design, synthesis and anti-inflammatory activity of 3-amino acid derivatives of ocotillol-type sapogenins

Ocotillol-type sapogenins (OTS) are major ginsenoside metabolites in human hepatic tissue. In order to better utilize OTS and derivatives thereof as anti-inflammatory compounds, present study produced multiple novel 3-amino acid OTS derivatives and evaluated their anti-inflammatory activity in vitro. The nitric oxide (NO) inhibitory activity of these compounds was used for OTS structure-activity relationship (SAR) evaluations, revealing that both R/S stereochemistry at C-24 and the amino acid type at C-3 influence such NO inhibitory activity. This activity was highest for an N-Boc-protected neutral aliphatic amino acid derivative of 24R-OTS (5a), which performed better than even hydrocortisone sodium succinate in vitro. Compound 5a was also able to markedly suppress the LPS-induced upregulation of TNF-α, IL-6, iNOS, and COX-2 via the NF-κB and MAPK pathways. This suggests that OTS derivatives may be valuable anti-inflammatory compounds worthy of further preclinical evaluation.

Bisindole alkaloids with nitric oxide inhibitory activities from an alcohol extract of the Isatis indigotica roots

Eight bisindole alkaloids including six undescribed ones (1a/1b–5) were isolated from an alcohol extract of the Isatis indigotica roots. Their structures and absolute configurations were supported by extensive spectroscopic data analysis, including 1D, 2D NMR, HRESIMS data, specific rotation data, and comparison of the experimental and calculated ECD data. Compounds 1a and 1b were determined to be a pair of enantiomers with a ratio of approximately 1:1 by chiral-phase chromatography analysis while compound 4 was elucidated as a new type of bisindole alkaloid with the aglycone categorized as bis(indole-1′/3″-yl)methane. All the isolated compounds were tested for their nitric oxide (NO) inhibitory effects and 1–4 and 6 exhibited inhibitory effects with IC50 values ranging from 11.0 to 37.6 μM.

Complementary NMR- and MS-based metabolomics approaches reveal the correlations of phytochemicals and biological activities in Phyllanthus acidus leaf extracts

Proton nuclear magnetic resonance (1H NMR)- and ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS)-based analytical tools are frequently used in metabolomics studies. These complementary metabolomics platforms were applied to identify and quantify the metabolites in Phyllanthus acidus extracted with different ethanol concentrations. In total, 38 metabolites were tentatively identified by 1H NMR and 39 via UHPLC-MS, including 30 compounds are reported for the first time from this plant. The partial least square analysis (PLS) revealed the metabolites that contributed to α-glucosidase and nitric oxide (NO) inhibitory activities, including kaempferol, quercetin, myricetin, phyllanthusol A, phyllanthusol B, chlorogenic, catechin, cinnamic coumaric, caffeic, quinic, citric, ellagic and malic acids. This study shows the significance of combining 1H NMR- and UHPLC-MS-based metabolomics as the best strategies in identifying metabolites in P. acidus extracts and establishing an extract with potent antioxidant, anti-diabetic, and anti-inflammatory properties.

Anti-inflammatory flavagline glycosides and putrescine bisamides from Aglaia perviridis leaves

abstract Four new cyclopenta[b]benzopyran glycosides (1–4), aglapervirisins J-M, two new putrescine bisamides (6–7), aglaiamides M − N, and a pair of novel flavagline enantiomer (±) aglapernin (8) were isolated from the leaves of A. perviridis. Their structures were elucidated based on comprehensive analysis of spectroscopic methods. The anti-inflammatory activities of those compounds were evaluated as inhibitory activities against lipopolysaccharide (LPS) induced nitric oxide (NO) production in RAW264.7 cell lines. Cyclopenta[b]benzopyran glycosides (1–4) showed weak nitric oxide inhibitory activity with IC50 values ranging from 29.5 to 43.6 μM, and the putrescine bisamides (5–7) exhibited potent nitric oxide inhibitory activity with IC50 values ranging from 7.4 to 19.5 μM.

Isolation and Identification of Lignans and Other Phenolic Constituents from the Stem Bark of Albizia julibrissin Durazz and Evaluation of Their Nitric Oxide Inhibitory Activity.

A dibenzylbutane-type lignan (16), along with eight furofuran-type (1–8), five furan-type (9–13), two dibenzylbutane-type (14 and 15), two bibenztetrahydronaphthalene-type lignans (17 and 18), two neolignans (19 and 20), and six phenolic derivatives (21–26) were isolated from an MeOH extract of the stem bark of Albizia julibrissin Durazz. The chemical structures of the obtained compounds were elucidated by nuclear magnetic resonance (NMR) and mass spectrometry (MS) analyses. Of the evaluated compounds, 14 were isolated from A. julibrissin and the Fabaceae family for the first time. Anti-inflammatory effects of the isolated analogs were investigated in terms of the inhibition of the nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated murine RAW264.7 macrophage cells. Ten compounds (10–12, 14, and 17–22) displayed significant dose-dependent inhibitory effects against the NO production, with IC50 values ranging from 5.4 to 19.2 µM. Moreover, eight compounds (1–4, 9, 13, 15, and 16) exhibited moderate inhibitory activities, with IC50 values ranging from 21.0 to 62.5 µM.

Identification of novel anti-inflammatory peptides from bee pollen (Apis mellifera) hydrolysate in lipopolysaccharide-stimulated RAW264.7 macrophages

Bee pollen protein was hydrolyzed using the commercial Alcalase, Flavourzyme and Neutrase enzymes. The Neutrase hydrolysate formed from a 1:1 (v/v) enzyme/substrate ratio (NH1) showed the highest nitric oxide (NO) radical scavenging activity. The NH1 was further separated into five fractions based on molecular weight (MW1–5) and MW1, the smallest weight fraction (< 0.65 kDa), possessed the highest NO inhibitory activity. The effects of NH1 on the production of NO were assessed by incubating with lipopolysaccharide-stimulated RAW264.7 macrophage cells. NO levels from the culture supernatants were determined by the Griess reaction. The results showed that MW1 suppressed the production of pro-inflammatory cytokines including cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), tumor interleukin-6 (IL-6) and necrosis factor transcript expression (TNF-α) in RAW264.7 macrophage cells. Thus, the MW1 fraction was fractionated using reversed-phase high-performance liquid chromatography into six principal fractions (H1–6), where H2, H3 and H4 showed strong NO inhibitory activity. Seven peptide sequences were obtained by quadrupole time-of-flight mass spectrometry, three of which displayed potent anti-inflammatory activity and may be useful ingredients in functional food and pharmaceutical drugs.

Antioxidant, α-Glucosidase, and Nitric Oxide Inhibitory Activities of Six Algerian Traditional Medicinal Plant Extracts and 1H-NMR-Based Metabolomics Study of the Active Extract.

Claims of effective therapy against diabetes using plants including Peganum harmala L., Zygophyllum album, Anacyclus valentinus L., Ammodaucus leucotrichus, Lupinus albus, and Marrubium vulgare in Algerian empirical medicine prompted our interest in evaluating their antidiabetic activity by screening their free radical scavenging (DPPH), α-glucosidase, and nitric oxide (NO) inhibitory activities as well as the total phenolic content (TPC). Extracts of the selected plants were prepared using different ratios of ethanol (0, 50, 80, and 100%). In this study, 100%, and 80% ethanol extracts of L. albus were found to be the most potent, in inhibiting α-glucosidase activity with IC50 values of 6.45 and 8.66 μg/mL, respectively. The 100% ethanol extract of A. leucotrichus exhibited the highest free radical scavenging activity with an IC50 value of 26.26 μg/mL. Moreover, the highest TPC of 612.84 μg GAE/mg extract was observed in M. vulgare, extracted with 80% ethanol. Metabolite profiling of the active extract was conducted using 1H-NMR metabolomics. Partial least square analysis (PLS) was used to assess the relationship between the α-glucosidase inhibitory activity of L. albus and the metabolites identified in the extract. Based on the PLS model, isoflavonoids (lupinoisoflavone G, lupisoflavone, lupinoisolone C), amino acids (asparagine and thiamine), and several fatty acids (stearic acid and oleic acid) were identified as metabolites that contributed to the inhibition of α-glucosidase activity. The results of this study have clearly strengthened the traditional claim of the antihyperglycemic effects of L. albus.

Four undescribed sulfur-containing indole alkaloids with nitric oxide inhibitory activities from Isatis tinctoria L. roots

Four undescribed sulfur-containing indole alkaloids, isatisindigoticanines H, I and isatindigosides F, G along with three known analogues were obtained from Isatis tinctoria L. roots. Isatisindigoticanines H and I contained an unusual 1-(thiazol-4-yl)butane-1,2,3,4-tetraol moiety while isatindigosides F and G possessed a new 3-[3-(1H-indole-2-yl)azet-2-yl]-1H-indole skeleton. The putative biosynthetic pathways of isatisindigoticanines H, I and isatindigosides F, G are proposed. The isolated compounds showed nitric oxide inhibitory effects with IC50 values ranging from 4.3 to 70.3 μM.

Highly Substituted Phenol Derivatives with Nitric Oxide Inhibitory Activities from the Deep-Sea-Derived Fungus Trichobotrys effuse FS524.

Chemical investigation on EtOAc extract of the deep-sea-derived fungus Trichobotrys effuse FS524 resulted in the isolation of six new highly substituted phenol derivatives, trieffusols A–F (1–6), along with ten known relative analogs (7–16). Their structures with absolute configurations were extensively characterized on the basis of spectroscopic data analyses, single-crystal X-ray diffraction experiments, and electronic circular dichroism (ECD) calculations. Structurally, trieffusols A and B shared an unprecedented ploy-substituted 9-phenyl-hexahydroxanthone skeleton with an intriguing 6-6/6/6 tetracyclic fused ring system, which is often encountered as significant moieties in the pharmaceutical drugs but rarely discovered in natural products. In the screening towards their anti-inflammatory activities of 1–6, trieffusols C and D exhibited moderate inhibitory activities against nitric oxide (NO) production in LPS-induced RAW 264.7 macrophages with IC50 values ranging from 51.9 to 55.9 μM.

Contribution of Flavonoids and Iridoids to the Hypoglycaemic, Antioxidant, and Nitric Oxide (NO) Inhibitory Activities of Arbutus unedo L.

This study aims at investigating the contribution of two classes of compounds, flavonoids and iridoids, to the bioactivity of Arbutus unedo L. leaves and fruits. The impact of different extraction procedures on phytochemicals content and hypoglycemic, antioxidant, and nitric oxide (NO) inhibitory activities of A. unedo fresh and dried plant materials was investigated. Ellagic acid 4-O-β-D-glucopyranoside, kaempferol 3-O-glucoside, and norbergenin were identified for the first time in this genus by using liquid chromatography-electrospray ionization-quadrupole-time of flight-mass spectrometry (LC-ESI-QTOF-MS). Three iridoids (gardenoside, geniposide, unedoside) are specifically identified in the leaves. Interestingly, asperuloside was extracted only from dried fruits by ethanol with Soxhlet apparatus. Extracts were screened for their potential antioxidant activities by using the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Activity Power (FRAP), and β-carotene bleaching tests. Based on the Global Antioxidant Score (GAS) calculation, the most promising antioxidant extract was obtained by hydroalcoholic maceration of dried leaves that showed half maximal inhibitory concentration (IC50) of 0.42 and 0.98 μg/mL in ABTS and DPPH assays, respectively. The hypoglycaemic activity was investigated by α-amylase and α-glucosidase inhibition tests. Extracts obtained by ethanol ultrasound extraction of fresh leaves and hydroalcoholic maceration of fresh fruits (IC50 of 19.56 and 28.42 μg/mL, respectively) are more active against α-glucosidase than the positive control acarbose (IC50 of 35.50 μg/mL). Fruit extracts exhibited the highest anti-inflammatory activity.

Euphanoids A and B, two new lathyrane diterpenoids with nitric oxide (NO) inhibitory activity from Euphorbia kansuensis

Two new lathyrane diterpenoids, euphanoids A and B (1 and 2), along with five known compounds (3–7) were isolated from the roots of Euphorbia kansuensis. Their structures were elucidated by spectroscopic analysis, and the absolute configuration of 1 was determined by single crystal X-ray diffraction. All of the isolates were screened for the inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 cells, and compounds 1 and 2 showed pronounced inhibition on NO production with IC50 values of 4.7 and 9.5 μM, respectively, being more active than the positive control, quercetin (IC50 = 10.8 μM).