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.     

Indole alkaloids from the roots of Isatis indigotica and their inhibitory effects on nitric oxide production

Three rare indole-2-S-glycosides, indole-3-acetonitrile-2-S-β-D-glucopyranoside (1), indole-3-acetonitrile-4-methoxy-2-S-β-D-glucopyranoside (2) and N-methoxy-indole-3-acetonitrile-2-S-β-D-glucopyranoside (3), together with 11 known indole alkaloids were isolated from the roots of Isatis indigotica Fort. (Cruciferae). The structures of 1–3 were elucidated on the basis of mass spectrometry and extensive 1D and 2D NMR spectroscopy. All of the isolated compounds were tested for inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages. A plausible biosynthesis pathway of 1–3 is also proposed.     

Two new abietane diterpenoids from the caulis and leaves of Callicarpa kochiana

Previous studies revealed that diterpenoids from Callicarpa genus were mainly of clerodane-type and phyllocladane-type, and abietane-type diterpenoids were seldom reported. In this paper, we reported two new abietane diterpenoids, kochianic acid A (1) and kochianic acid B (2), together with two known abietane-type diterpenoids, pedunculatic acid B (3) and 7α, 15-dihydroxydehydroabietic acid (4), which were all isolated from Callicarpa kochiana. The structures of the new compounds 1 and 2 were elucidated on the basis of extensive spectroscopic analysis, including HSQC, HMBC, ¹H-¹H COSY, ROESY and finally confirmed by single-crystal X-ray diffraction.     

Sesquiterpenes from Ulmus davidiana var. japonica with the inhibitory effects on lipopolysaccharide-induced nitric oxide production

Investigation of antiinflammatory constituents of the stem and root barks of Ulmus davidiana var. japonica resulted in the isolation of three guaiane type sesquiterpenes, torilin, 1-hydroxytorilin, together with a new derivative, (1beta, 7beta, 8beta, 10beta)-1,8,11-trihydroxy-4-guaien-8-angeloyl-3-one named 1-hydroxytorilin A. All the three sesquiterpenes inhibited lipopolysaccharide-induced nitric oxide production in murine microglial BV2 cells.     

Polyphenols from the stems of Morus alba and their inhibitory activity against nitric oxide production by lipopolysaccharide-activated microglia

Neuroinflammatory processes are involved in the pathogenesis of many neurodegenerative disorders. Microglial cells, the main immune cells of the central nervous system, represent a target of interest to search for naturally occurring anti-inflammatory products. In this study, we evaluated the anti-inflammatory properties of polyphenols obtained from the stems of Morus alba. This edible species, known as white mulberry, is frequently studied because of its traditional use in Asian medicine and its richness in different types of polyphenols, some of which are known to be phytoalexins. One new coumarin glycoside, isoscopoletin 6-(6-O-β-apiofuranosyl-β-glucopyranoside) (1) was mainly isolated by CPC (centrifugal partition chromatography) from this plant, together with seven known polyphenols (2–8). Their structures were established on the basis of spectroscopic analyses including extensive 2D NMR studies. The eight isolated compounds were evaluated for their inhibitory activities on nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. The absence of cell toxicity is checked by a MTT assay.     

Sesquiterpenes from Vladimiria souliei and their inhibitory effects on NO production

As a part of our ongoing search for plant-derived compounds that inhibit nitric oxide production, the methanol extract of the roots of Vladimiria souliei was found to show significant inhibitory effects on INF-γ-induced nitric oxide production in murine macrophage RAW264.7 cells. Bioactivity-guided isolation of the extract yielded two most active sesquiterpenes, including a new compound, named souliene A (1) and alismol (2). Their structures were elucidated by spectroscopic methods (IR, ESIMS, HRESIMS, 1D and 2D NMR). Two isolates showed promising inhibitory effects on INF-γ-induced nitric oxide production in murine macrophage RAW264.7 cells.     

ent-Isopimarane diterpenoids of the leaves from Rabdosia forrestii

Two new diterpenes, forrestin H, ent-isopimaran-8 beta, 15R, 16-triol (1), forrestin I, ent-isopimaran-16-acetoxy-8 beta, 15R-diol (2) and the acetonide derivative of forrestin H were isolated from the leaves of Rabdosia forrestii. The structures were established on the basis of NMR spectroscopic analysis and of the modified Mosher's (1H) method.     

Chemical constituents of Aloe barbadensis Miller and their inhibitory effects on phosphodiesterase-4D

Aloe barbadensis Mill has been used as food and medicine for a long time. In order to investigate the chemical constituents of A. barbadensis and their inhibitory activities towards phosphodiesterase-4D (PDE4D), 70% methanol extract of the dried A. barbadensis powder was employed. Phytochemical investigation has led to the isolation of three new chromones, 5-(hydroxymethyl)-7-methoxy-2-methylchromone (4), 5-((4E)-2′-oxo-pentenyl)-2-hydroxymethylchromone (6), and 7-hydroxy-5-(hydroxymethyl)-2-methylchromone (7), together with eighteen known compounds. Their chemical structures were determined based on spectroscopic methods including UV, IR, 1D and 2D NMR, and HRMS spectrometry. In addition, their inhibition against PDE4D was evaluated using tritium-labeled adenosine 3′,5′-cyclic monophosphate (³H-cAMP) as the substrate. Inhibition was calculated by the variation of radioactivity after the reaction, and compounds 1–4, 10, and 21 exhibited certain inhibitory activities towards PDE4D, which can provide an explanation why A. barbadensis can serve as anti-inflammatory agents.     

Lathyrane diterpenes from Euphorbia prolifera and their inhibitory activities on LPS-induced NO production

A new lathyrane diterpene (1), an unreported spectroscopic data lathyrane diterpenene (2), and two known analaogues (3 and 4) have been isolated from Euphorbia prolifera. Their structures were elucidated as (12E,2S,3S,4R,5R,6S,9S,11S,15R)-3-butyryloxy-5,15-diacetoxy-6,17-epoxylathyra- 12-en-14-one (1), (12E,2S,3S,4R,5R,6S,9S,11S,15R)-3-propionyloxy-5,15-diacetoxy-6,17- epoxylathyra-12-en-14-one (2), (12E,2S,3S,4R,5R,6S,9S,11S,15R)-3-benzoyloxy-5,15-diacetoxy -6,17-epoxylathyra-12-en-14-one (3), and 15-O-acetyl-17-hydroxyjolkinol (4) by spectroscopic methods (IR, ESIMS, HR-ESIMS, NMR, and X-ray crystallography). The inhibitory activities on LPS-induced NO production of these diterpenes were evaluated and compounds 1, 3 and 4 showed inhibitory effects.     

Inhibition of nitric oxide production on LPS-activated macrophages by kazinol B from Broussonetia kazinoki

The ethyl acetate soluble fraction of Broussonetia kazinoki at 50 microg/ml showed a significant inhibition (78.2%) of nitric oxide (NO) in lipopolysaccharide activated macrophages. Kazinol B, an isoprenylated flavan, was identified as the active principle. It inhibits the NO synthesis with an IC(50) of 21.6 microM.     

The inhibitory effects of Gelam honey and its extracts on nitric oxide and prostaglandin E2 in inflammatory tissues

We investigated the effects of honey and its methanol and ethyl acetate extracts on inflammation in animal models. Rats’ paws were induced with carrageenan in the non-immune inflammatory and nociceptive model, and lipopolysaccharide (LPS) in the immune inflammatory model. Honey and its extracts were able to inhibit edema and pain in inflammatory tissues as well as showing potent inhibitory activities against NO and PGE₂ in both models. The decrease in edema and pain correlates with the inhibition of NO and PGE₂. Phenolic compounds have been implicated in the inhibitory activities. Honey is potentially useful in the treatment of inflammatory conditions.     

neo-Clerodane diterpenes from Ajuga decumbens and their inhibitory activities on LPS-induced NO production

A phytochemical investigation of the whole plants of Ajuga decumbens led to the isolation of three new (1, 2a, and 2b) and three known (3a−3c) neo-clerodane diterpenes. Their structures were elucidated by spectroscopic data analysis (IR, ESIMS, HR-ESIMS, 1D and 2D NMR), and the structure of 1 was confirmed by X-ray crystallography. The inhibitory activities on LPS-induced NO production of the six diterpenes were evaluated and compounds 2a, 2b, and 3a showed inhibitory effects.     

Enmein-type diterpenoids from the aerial parts of Isodon rubescens and their cytotoxicity

Three new enmein-type diterpenoids, jianshirubesins A–C (1–3), together with ten known compounds, were isolated from the aerial parts of Isodon rubescens. Their structures were established by using spectroscopic methods, and the absolute configuration of compound 1 was confirmed by a single-crystal X-ray diffraction analysis. All compounds except 3 were evaluated for their in vitro cytotoxicity by MTT assay, and compounds 5 and 10 exhibited significant inhibitory ability on selected cell lines.     

Triterpenoids from Calophyllum inophyllum and their growth inhibitory effects on human leukemia HL-60 cells

A new friedelane-type triterpene (1), along with seven known triterpenoids, was isolated from the stems and leaves of Calophyllum inophyllum Linn. Their structures were established as 3β, 23-epoxy-friedelan-28-oic acid (1), friedelin (2), epifriedelanol (3), canophyllal (4), canophyllol (5), canophyllic acid (6), 3-oxo-friedelan-28-oic acid (7), and oleanolic acid (8) by spectroscopic methods (NMR, EI-MS). The growth inhibitory effects of these triterpenoids on human leukemia HL-60 cells were determined.     

Effects of a nitric oxide donor and nitric oxide scavengers on Sorbus pohuashanensis embryo germination

The effects of an exogenous nitric oxide donor(sodium nitroprusside, SNP), a NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxode(PTIO) and carboxy-PTIO potassium salt(c PTIO) on the embryo germination of Sorbus pohuashanensis were studied in a petri dish test. SNP at 0.5–5 mmol L-1 increased germination percentage, mean time to germination, germination index and germination energy compared with the control to different degrees. Treatment with 2 mmol L-1 SNP improved germination most significantly; embryo germination percentage for mother tree 1(91.11%) and mother tree 2(64.44%) were much higher than the control. In addition,excessive SNP levels did not enhance embryo germination.Combined treatment with SNP and an NO scavenger delayed embryo germination. Treatment with c PTIO inhibited embryo germination; germination percentage was 42.22% and was lower than that of the control. These results show that low concentrations of exogenous NO can enhance the embryo germination of S. pohuashanensis,providing a simple, effective way for promoting germination of S. pohuashanensis.     

Effects of Morus alba leaf extract on the production of nitric oxide, prostaglandin E2 and cytokines in RAW264.7 macrophages

Morus alba leaf methanolic extract and its fractions (chloroform, butanol, and aqueous fractions) were found to inhibit NO production in LPS-activated RAW264.7 macrophages without an appreciable cytotoxic effect at concentration from 4 to 100 microg/ml. LPS-induced PGE2 production was significantly reduced only by butanol fraction. In addition, M. alba leaf extract and its fractions significantly decreased the production of TNF-alpha. These findings suggest that M. alba leaf extract seems to be able in suppressing inflammatory mediators. Moreover, the inhibitory activities on COX-2 and iNOS of its butanol fraction are warranted for further elucidation of active principles for development of new antiinflammatory agents.     

Responses of Spodoptera littoralis larvae to Tunisian plant extracts and to neo-clerodane diterpenoids isolated from Ajuga pseudoiva leaves

Thirteen plants growing in Tunisia were tested against Spodoptera littoralis larvae. From the acetone extract of Ajuga pseudoiva leaves, showing interesting antifeedant activity, three new (1-3) and two known (4-5) active clerodane diterpenoids were isolated following a bioassay-guided chromatography.     

Linalool production from the leaves of Bursera aloexylon and its antimicrobial activity

The oil of the leaves of Bursera aloexylon was found to contain a high linalool level (96.7 %). The antimicrobial activity tests indicated that the oil was effective against Rhodococcus equi (0.60 mg/ml) and Staphylococcus epidermides (0.15 mg/ml).     

Hepatoprotective effects of polyprenols from Ginkgo biloba L. leaves on CCl4-induced hepatotoxicity in rats

The hepatoprotective effects of polyprenols from Ginkgo biloba L. leaves were evaluated against carbon tetrachloride induced hepatic damage in Sprague-Dawley rats. The elevated levels of serum ALT, AST, ALP, ALB, TP, HA, LN, TG, and CHO were restored towards normalization significantly by GBP in a dose dependent manner. The biochemical observations were supplemented with histopathological examination of rat liver sections. Meanwhile, GBP also produced a significant and dose-dependent reversal of CCl₄-diminished activity of the antioxidant enzymes and reduced CCl₄-elevated level of MDA. In general, the effects of GBP were not significantly different from those of the standard drug Essentiale.