QSAR prediction, synthesis, anticancer evaluation, and mechanistic investigations of novel sophoridine derivatives as topoisomerase I inhibitors.

Sophoridine, which is derived from the Leguminous plant Sophora alopecuroides L., has certain pharmacological activity as a new anticancer drug. Herein, a series of novel N-substituted sophoridine derivatives was designed, synthesized and evaluated with anticancer activity. Through QSAR prediction models, it was discovered that the introduction of a benzene ring as a main pharmacophore and reintroduced into a benzene in para position on the phenyl ring in the novel sophoridine derivatives improved the anticancer activity effectively. In vitro, 28 novel compounds were evaluated for anticancer activity against four human tumor cell lines (A549, CNE-2, HepG-2, and HEC-1-B). In particular, Compound 26 exhibited remarkable inhibitory effects, with an IC50 value of 15.6 µM against HepG-2 cells, surpassing cis-Dichlorodiamineplatinum (II). Molecular docking studies verified that the derivatives exhibit stronger binding affinity with DNA topoisomerase I compared to sophoridine. In addition, 26 demonstrated significant inhibition of DNA Topoisomerase I and could arrest cells in G0/G1 phase. This study provides valuable insights into the design and synthesis of N-substituted sophoridine derivatives with anticancer activity.

Antioxidant activity of Haloxylon scoparium alkaloid extracts from Figuig region (southeastern of Morocco)

Abstract The aim of this paper is to study the chemical composition of alkaloids present in Haloxylon scoparium Pomel extracts and to evaluate their antioxidant capacity. The alkaloids were isolated from two parts of Haloxylon scoparium plant by two extraction protocols. and The quantitative study made it possible to propose the best protocol for the extraction of the alkaloids. Moreover, GC-MS analysis of alkaloid extracts allowed us to determine their chemical composition. Haloxylon scoparium contains four types of alkaloids: tetraisoquinolines, phenylethylamines, tryptolines and tryptamines. The main compounds are the tetraisoquinolines type, the predominant product of which was N-methylsalsoline. These compounds present a great interest for the researchers due to their various pharmacological and biological activities. The antioxidant effect of the different plant extracts was studied by two methods: the ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picryl hydrazyl free radical (DPPH·) scavenging tests. The results show that extracts of root part are more active than those from aerial part; the acetone/water extract is the most powerful. The interesting results obtained in this study will be supplemented by other analyses and biological tests in order to better valorize this plant.

Synthetic access to thiolane-based therapeutics and biological activity studies.

Secondary metabolites isolated from bioactive extracts of natural sources iteratively pioneer the research in drug discovery. Modern medicine is often inspired by bioactive natural products or the bio-functional motifs embedded in them. One of such consequential bio-functional motifs is the thiolane unit. Thiolane-based bioactive organic compounds have manifested a plethora of astonishing biological activities such as anti-viral, anti-cancer, anti-platelet, α-glucosidase inhibition, anti-HIV, immunosuppressive and anti-microbial activities which renders them excellent candidates in drug discovery. Hence, to scale up the accessibility of thiolane-based therapeutics its chemical syntheses is essential and in addition; a sneak peek in its biosynthesis would give a perspective for developing biomimetic syntheses. This review highlights the development of important thiolane-based therapeutics such as (i) Nuphar sesquiterpene thioalkaloids (ii) Thiosugar sulphonium salts from Salacia sp. (iii) Albomycins (iv) Thiolane-based therapeutics from Allium sp. (v) 4'-thionucleosides summarizing various synthetic strategies, biosynthesis and biological activity studies, covering literature till 2021. We anticipate that this review will inspire chemists and biochemists to take up the challenges encountered in the synthesis and development of thiolane-based therapeutics.

Deconstructive Asymmetric Total Synthesis of Morphine-Family Alkaloid (-)-Thebainone†A.

Herein, we describe the development of a deconstructive strategy for the first asymmetric synthesis of (-)-thebainone A, capitalizing on an enantioselective C-C bond activation and a C-O bond cleavage reaction. The rhodium-catalyzed asymmetric "cut-and-sew" transformation between sterically hindered trisubstituted alkenes and benzocyclobutenones allowed efficient construction of the fused A/B/C rings and the quaternary center of the natural product. The newly optimized conditions show broad substrate scope and excellent enantioselectivity (up to 99.5:0.5 er). Taking advantage of boron-mediated ether bond cleavage, we completed the synthesis of the morphine alkaloid (-)-thebainone A by two complementary routes.

Ideality in Context: Motivations for Total Synthesis.

Total synthesis-the ultimate proving ground for the invention and field-testing of new methods, exploration of disruptive strategies, final structure confirmation, and empowerment of medicinal chemistry on natural products-is one of the oldest and most enduring subfields of organic chemistry. In the early days of this field, its sole emphasis focused on debunking the concept of vitalism, that living organisms could create forms of matter accessible only to them. Emphasis then turned to the use of synthesis to degrade and reconstitute natural products to establish structure and answer questions about biosynthesis. It then evolved to not only an intricate science but also a celebrated form of art. As the field progressed, a more orderly and logical approach emerged that served to standardize the process. These developments even opened up the possibility of computer-aided design using retrosynthetic analysis. Finally, the elevation of this field to even higher levels of sophistication showed that it was feasible to synthesize any natural product, regardless of complexity, in a laboratory. During this remarkable evolution, as has been reviewed elsewhere, many of the principles and methods of organic synthesis were refined and galvanized. In the modern era, students and practitioners are still magnetically attracted to this field due to the excitement of the journey, the exhilaration of creation, and the opportunity to invent solutions to challenges that still persist. Contemporary total synthesis is less concerned with demonstrating a proof of concept or a feasible approach but rather aims for increased efficiency, scalability, and even "ideality." In general, the molecules of Nature are created biosynthetically with levels of practicality that are still unimaginable using the tools of modern synthesis. Thus, as the community strives to do more with less (i.e., innovation), total synthesis is now focused on a pursuit for simplicity rather than a competition for maximal complexity. In doing so, the practitioner must devise outside-the-box strategies supplemented with forgotten or newly invented methods to reduce step count and increase the overall economy of the approach. The downstream applications of this pursuit not only empower students who often go on to apply these skills in the private sector but also lead to new discoveries that can impact numerous disciplines of societal importance. This account traces some select case studies from our laboratory over the past five years that vividly demonstrate our own motivation for dedicating so much effort to this classic field. In aiming for simplicity, we focus on the elusive goal of achieving ideality, a term that, when taken in the proper context, can serve as a guiding light to point the way to furthering progress in organic synthesis.

Marine Alkaloid Pityriacitrin and Its Analogues: Discovery, Structures, Synthetic Methods and Biological Properties.

Pityriacitrin is a natural marine alkaloid with a typical ß-carboline scaffold, and which has been demonstrated to exhibit diverse biological functions. The special structural features for pityriacitrin lead to the increasing research interest and the emergence of versatile derivatives, and many pityriacitrin analogues have been isolated or synthesized over the past decades. The structural diversity and evolved biological activity of these natural alkaloids can offer opportunities for the development of highly potential novel drugs with a new mechanism of action, and therefore, the aim of this brief review is to describe the discovery, synthesis, and biological properties of natural pityriacitrin and its derivatives, as well as the isolation source.

Variation of spacer type and topology of phenyl moiety in 2-pyridone core of 4-oxo-3-N-methylcytisine; effect of synthesized compounds on rat's behavior in conditioned passive avoidance reflex (CPAR) test.

Novel derivatives of 4-oxo-3-methylcytisine with phenyl moiety bonded to starting molecule through various spacers were obtained from the 9-amino, -halo, -formyl and 11-halo precursors by reductive alkylation of amines, generation of amide, as well as thio- and carboxamide functions, cross-coupling reactions, aldehyde condensation and reduction of unsaturated 'C-C' bonds. Ability of synthesized compounds to influence the learning and memory was preliminary assessed in conditioned passive avoidance reflex (CPAR) test in rats. It was shown, that derivatives with phenyl group at 11 carbon atom influence the learning and memory in CPAR test more effectively than other compounds. The hit-compound (3-methyl-11-(2-phenylvinyl)-3,5,6-trihydro-2H-1,5-methanopyrido[1,2-a][1,5]diazocine-4,8(1H)-dione) with the best values of 'latency' and 'time spent in the dark compartment' has been identified as a perspective scaffold for synthesis of novel derivatives of (-)-cytisine with potential neuropharmacological activity.

Synthesis of new selective cytotoxic ricinine analogues against oral squamous cell carcinoma.

Sixteen new analogues were synthesized from ricinine and tested alongside with seven known analogues for their cytotoxic activity against oral cancer (SAS cells) and normal epithelial cells (L132 cells). In contrast to 5-FU, the synthesized ricinine analogues did not show toxicity to normal cells. However, some of them inhibited the proliferation of oral cancer cells at 25 µM as evident from the MTT assay results. Ricinine analogue (19) was shown to be the most active derivative (69.22% inhibition). Potential targets involved in the oral cancer inhibitory activity of compound 19 were investigated using in-silico studies and western blot analysis. PTP1B was predicted to be a target for ricinine using reverse docking approach. This prediction was confirmed by western blot analysis that revealed the downregulation of PTP1B protein by compound 19. Moreover, it showed downregulation of COX-2 which is also extensively expressed in oral cancer.

Total Synthesis of Daphniphyllum Alkaloids: From Bicycles to Diversified Caged Structures.

Native to the Asia-Pacific region and widely applied in traditional Chinese medicine, the genus Daphniphyllum has produced over 330 known Daphniphyllum alkaloids. Investigations into these alkaloids have shown an exceptional range of interesting bioactivities. Challenging and caged polycyclic architectures and the promising biological profiles make Daphniphyllum alkaloids intriguing synthetic targets. Based on their backbones, these alkaloids can be categorized into 13-35 structurally distinct subfamilies. In addition to our work, almost 30 impressive total syntheses of Daphniphyllum alkaloids from seven subfamilies, namely, daphniphylline-type, secodaphniphylline-type, daphnilactone A-type, bukittinggine-type, daphmanidin A-type, calyciphylline A-type, and calyciphylline B-type alkaloids, have been reported by 11 research groups. However, many Daphniphyllum alkaloid subfamilies remain inaccessible by chemical synthesis.In this Account, we summarize our recent endeavors in the total synthesis of Daphniphyllum alkaloids commencing from simple chiral bicyclic synthons. Daphniphyllum alkaloids with diversified skeletons from four different subfamilies, namely, calyciphylline A-type, daphnezomine A-type, bukittinggine-type, and yuzurimine-type alkaloids, have been achieved. Furthermore, the tricyclic core structure of daphniglaucin C-type alkaloids daphnimacropodines was also synthesized. First, we describe a 14-step synthesis of calyciphylline A-type alkaloid (-)-himalensine A, which features a mild Cu-mediated nitrile hydration, an intramolecular Heck reaction to assemble the pivotal 2-azabicyclo[3.3.1]nonane moiety, and a Meinwald rearrangement to introduce the critical oxidative state into the skeleton. We then introduce the synthesis of daphnezomine A-type alkaloid dapholdhamine B, which possesses a unique aza-adamantane core. This target molecule was fabricated using key reactions including Huang's amide-activation-annulation. An unexpected radical detosylation during the synthesis of dapholdhamine B further inspired an ambitious radical cyclization cascade strategy, which eventually led to an efficient total synthesis of bukittinggine-type alkaloid (-)-caldaphnidine O. This highly chemo-, regio-, and stereoselective radical reaction cascade also shed light on the synthetic strategy of other alkaloids with caged structures. We next describe the first total synthesis of yuzurimine-type alkaloid (+)-caldaphnidine J. The key steps in our approach include a Pd-catalyzed regioselective hydroformylation and a novel Swern oxidation/ketene dithioacetal Prins reaction cascade. The work has achieved the first synthesis of a member of the largest subfamily of Daphniphyllum alkaloids. Finally, we show our efforts toward the total synthesis of daphniglaucin C-type alkaloids. Overall, we hope that the interesting strategies and synthetic methods demonstrated in our efforts could inspire a wide variety of additional applications to natural product synthesis.

Enantioselective total syntheses of (+)-stemofoline and three congeners based on a biogenetic hypothesis.

The powerful insecticidal and multi-drug-resistance-reversing activities displayed by the stemofoline group of alkaloids render them promising lead structures for further development as commercial agents in agriculture and medicine. However, concise, enantioselective total syntheses of stemofoline alkaloids remain a formidable challenge due to their structural complexity. We disclose herein the enantioselective total syntheses of four stemofoline alkaloids, including (+)-stemofoline, (+)-isostemofoline, (+)-stemoburkilline, and (+)-(11S,12R)-dihydrostemofoline, in just 19 steps. Our strategy relies on a biogenetic hypothesis, which postulates that stemoburkilline and dihydrostemofolines are biogenetic precursors of stemofoline and isostemofoline. Other highlights of our approach are the use of Horner-Wadsworth-Emmons reaction to connect the two segments of the molecule, an improved protocol allowing gram-scale access to the tetracyclic cage-type core, and a Cu-catalyzed direct and versatile nucleophilic alkylation reaction on an anti-Bredt iminium ion. The synthetic techniques that we developed could also be extended to the preparation of other Stemona alkaloids.

Natural Products as Anti-Cancerous Therapeutic Molecules Targeted towards Topoisomerases.

Topoisomerases are reported to resolve the topological problems of DNA during several cellular processes, such as DNA replication, transcription, recombination, and chromatin remodeling. Two types of topoisomerases (Topo I and II) accomplish their designated tasks by introducing single- or double-strand breaks within the duplex DNA molecules, and thus maintain the proper structural conditions of DNA to release the topological torsions, which is generated by unwinding of DNA to access coded information, in the course of replication, transcription, and other processes. Both the topoisomerases have been looked at as crucial targets against various types of cancers such as lung, melanoma, breast, and prostate cancers. Conceptually, targeting topoisomerases will disrupt both DNA replication and transcription, thereby leading to inhibition of cell division and consequently stopping the growth of actively dividing cancerous cells. Since the discovery of camptothecin (an alkaloid) as an inhibitor of Topo I in 1958, a number of derivatives of camptothecin were developed as potent inhibitors of Topo I. Two such derivatives of camptothecin, namely, topotecan and irinotecan, have been commonly used as US Food and Drug Administration (FDA) approved drugs against Topo I. Similarly, the first Topo II inhibitor, namely, etoposide, an analogue of podophyllotoxin, was developed in 1966 and got FDA approval as an anti-cancer drug in 1983. Subsequently, several other inhibitors of Topo II, such as doxorubicin, mitoxantrone, and teniposide, were developed. These drugs have been reported to cause accumulation of cytotoxic non-reversible DNA double-strand breaks (cleavable complex). Thus, the present review describes the anticancer potential of plant-derived secondary metabolites belonging to alkaloids, flavonoids and terpenoids directed against topoisomerases. Furthermore, in view of the recent advances made in the field of computer-aided drug design, the present review also discusses the use of computational approaches such as ADMET, molecular docking, molecular dynamics simulation and QSAR to assess and predict the safety, efficacy, potency and identification of these potent anti-cancerous therapeutic molecules.

Anti-cancer potential of sophoridine and its derivatives: Recent progress and future perspectives.

Cancer is the second leading cause of mortality and has resulted in about 9.6 million deaths around the world in 2018. Cancer-caused deaths are expected to be 11.5 million by 2030 all over the world. Because of the fatal nature of cancer, substantial efforts are made all over the world to combat it. Phytoconstituents such as certain alkaloids, saponins, tannins, polyphenols, and terpenoids exhibit anticancer effects. Sophoridine is a tetracyclic quinolizidine alkaloid isolated from the stem and leaves of medicinal plants Sophora alopecuroides L., and Euchresta japonica Benth, and roots of Sophora alopecuroides Ait. Chinese Food and Drug Administration (CFDA) approved sophoridine as an antitumor agent in 2005. This review covers the antitumor activities of sophoridine and its derivatives. The efficacy of sophoridine analogs is expressed with respect to their half-maximal inhibitory concentration (IC50 values). Structure-activity relationship (SAR) study for most of the sophoridine derivatives has been explained. Moreover, the current market of anticancer drugs and its expected growth are discussed. Prospects provide suggestions and clues for novel sophoridine-based anticancer agents with enhanced expected efficacy and minimum toxicity.

Total Synthesis of (-)-Anaferine: A Further Ramification in a Diversity-Oriented Approach.

The piperidine ring is a widespread motif in several natural bioactive alkaloids of both vegetal and marine origin. In the last years, a diversity-oriented synthetic (DOS) approach, aimed at the generation of a library of piperidine-based derivatives, was developed in our research group, employing commercially available 2-piperidine ethanol as a versatile precursor. Here, we report the exploration of another ramification of our DOS approach, that led us to the stereoselective total synthesis of (-)-anaferine, a bis-piperidine alkaloid present in Withania somnifera extract. This natural product was obtained in 9% overall yield over 13 steps, starting from a key homoallylic alcohol previously synthesised in our laboratory. Therefore, the collection of piperidine-derivatives accessible from 2-piperidine ethanol was enriched with a new, diverse scaffold.

Phytochemical and pharmacological attributes of piperine: A bioactive ingredient of black pepper.

Plants are vital for the wellbeing of humankind in a variety of ways. Some plant extracts contain antimicrobial properties that can treat different pathogens. Most of the world's population relies on medicinal plants and natural products for their primary health care needs. Therefore, there is a growing interest in natural products, medicinal plants, and traditional medicine along with a desire to design and develop novel plant-based pharmaceuticals. These plant-based pharmaceuticals may address the concerns of reduced efficacy of synthetic antibiotics due to the emergence of drug-resistant pathogens. In this regard, some plant extracts from black pepper (Piper nigrum) with antimicrobial properties, including piperine, have the potential to be used as natural dietary supplements together with modern therapeutic approaches. This review highlights possible applications of piperine as the active compound in the fields of rational drug design and discovery, pharmaceutical chemistry, and biomedicine. We discuss different extraction methods and pharmacological effects of the analyzed substance to pave the way for further research strategies and perspectives towards the development of novel herbal products for better healthcare solutions.

MYMD-1, a Novel Immunometabolic Regulator, Ameliorates Autoimmune Thyroiditis via Suppression of Th1 Responses and TNF-α Release.

MYMD-1 is a synthetic derivative of tobacco alkaloids, compounds that possess immunoregulatory properties and have been linked to the epidemiological observation that smoking reduces the odds of developing thyroid Abs and hypothyroidism. To assess the effect and mechanism(s) of the action of MYMD-1, we chose the NOD.H-2h4 mouse model of spontaneous thyroiditis. We began in vitro using T cells isolated from NOD.H-2h4 spleens and found that MYMD-1 suppressed TNF-α production by CD4+ T cells in a dose-dependent manner. We then treated 58 NOD.H-2h4 mice for 12 wk with either unsupplemented water that contained (10 mice) or did not contain (16 mice) MYMD-1 (185 mg/l) or water supplemented with sodium iodide (500 mg/l) that contained (16 mice) or did not contain (16 mice) MYMD-1. Mice were bled at baseline and then every 2 wk until sacrifice. MYMD-1 decreased the incidence and severity (p < 0.001) of thyroiditis, as assessed by histopathology. Similarly, the number of CD3+ T cells and CD19+ B cells infiltrating the thyroid was dampened by MYMD-1, as assessed by flow cytometry. Interestingly, the subset of thyroidal CD3+CD4+Tbet+RORγT- effector Th1 cells and the systemic levels of TNF-α were decreased by MYMD-1. Serum thyroglobulin Abs decreased in the MYMD-1 group. Thyroid hormones did not differ among the four groups, whereas thyroid-stimulating hormone increased upon iodine supplementation but remained normal in MYMD-1-treated mice. Overall, the study suggests that MYMD-1 ameliorates thyroiditis acting on specific lymphoid subsets. Further studies, including other models of autoimmunity, will confirm the potential clinical use of MYMD-1 as a novel immunometabolic regulator.

Synthesis, characterization and in vitro biological evaluation of two matrine derivatives.

Matrine is a traditional Chinese medicine and botanical pesticide with broad biological activities, including pharmacological and agricultural activities. In present work, two matrine derivatives have been successfully synthesized via introducing indole and cyclohexylamino to 13 position of matrine, respectively, with sophocarpine as starting material, and structurally characterized via infrared spectroscopy(IR), MS, 1 H NMR, 13 C NMR and X-ray crystal diffraction. The results of the in vitro biological activity tests showed that these two matrine derivatives exhibited even better activities against human cancer cells Hela229 and insect cell line Sf9 from Spodoptera frugiperda (J. E. Smith) than that of parent matrine, suggesting that the heterocyclic or cyclic group can dramatically increase the biological activity of matrine. It is worth to mention that 13-indole-matrine could possibly inhibit the growth of insect cells or human cancer cells by inducing cell apoptosis. The results of the present study provide useful information for further structural modifications of these compounds and for exploring new, potent anti-cancer agents and environment friendly pesticides.

Salt-assisted dispersive liquid-liquid microextraction for enhancing the concentration of matrine alkaloids in traditional Chinese medicine and its preparations.

A fast, simple, and efficient salt-assisted dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography was developed and introduced for the simultaneous enrichment, extraction, and determination of the trace levels of matrine alkaloids (sophoridine, matrine, and sophocarpine) in Sophorae Flavescentis Radix and Composite Kushen injection. Compared with conventional dispersive liquid-liquid microextraction, the proposed method, with added salt but without dispersant and centrifuging, makes the operation simpler, greener, and leads to a higher enrichment factor. The crucial parameters affecting the enrichment factors of target analytes, such as type and volume of extraction solvent, pH of sample phase, salt concentration, volume of sample phase, and extraction time, were investigated and optimized, meanwhile, the extraction mechanism of the method was analyzed and described. Under the optimized conditions, the enrichment factors of the three matrine alkaloids were 150, 178, and 227, respectively. Good linearities (r2  ≥ 0.9992) for all analytes, low limits of detection (less than 0.08 ng/mL), satisfactory precisions (2.1-12.3%), and accuracies (recoveries, 99.3-103.9%) were achieved. The experimental results showed that the approach is a simple, fast, green, eco-friendly, and sensitive method and can be used for the preconcentration and determination of matrine alkaloids in traditional Chinese medicines and their preparations.

Synthetic approaches to access acortatarins, shensongines and pollenopyrroside; potent antioxidative spiro-alkaloids with a naturally rare morpholine moiety.

Pyrrole spiroketal alkaloids (PSAs) are a class of novel natural products that have been recently disclosed. Acortatarin A and acortatarin B, two potent antioxidative spiroalkaloids with a naturally rare morpholine moiety, are important members of this class. These spiroalkaloids are isolated from Acorus tatarinowii, Brassica campestris, Capparis spinose, bread crust, Xylaria nigripes and medicine Shensong Yangxin and could inhibit significantly the reactive oxygen species (ROS) production in high-glucose-induced mesangial cells in a time- and dose-dependent manner. Hence, these natural products are promising starting points for the formation of new therapeutics to medicate cardiovascular diseases, cancer, diabetic complications, and other diseases in which ROS are implicated. The impressive structure combined with an interesting pharmacological activity prompted synthetic chemists to construct an asymmetric synthetic strategy that could be used to access structural derivatives in addition to the larger quantities of natural products required for further biological investigations. This review summarizes the current state of the literature regarding with the synthesis of acortatarin A and B and its other family members viz. shensongine A, B and C, and pollenopyrroside A. The present review discusses the pros and cons of synthetic methodologies, which would be beneficial for further developments in the synthetic methodologies. Hopefully, this struggle pushes the reader's mind to consider new perspectives, think differently and forge new connections.

The synthesis and anti-metastatic effects of optical isomers of ionone alkaloid 9-(N,N-dimethyl)-4,7-megastigmedien-3-one.

Ionone alkaloid 9-(N,N-dimethyl)-4,7-megastigmedien-3-one (compound 1) is a new anti-metastatic natural product. However, it was previously reported as optical isomers mixture. Herein, the optical isomers (6a-6d) of compound 1 were synthesized. The absolute configurations of 6a-6d were determined by ECD experiments and calculated spectra with time-dependent density functional theory (TDDFT). The anti-metastatic effects of the optical isomers were examined by transwell assay. These results revealed that compound 6a had potential anti-metastatic activity with an IC50 value of 0.512 ±â€¯0.093 µM.

Anti-inflammatory Effects of Canthin-6-one Alkaloids from Ailanthus altissima.

Canthin-6-one (CO) alkaloids possess various biological activities, including antibacterial, antitumor, antifungal, and antiviral activities. However, their anti-inflammatory effects and underlying molecular mechanisms are poorly characterized. This study aimed to investigate the anti-inflammatory effects of CO and its derivative 5-(1-hydroxyethyl)-canthin-6-one (5-HCO), isolated from the stem barks of Ailanthus altissima in lipopolysaccharide (LPS)-stimulated macrophages. CO (1 and 5 µM) and 5-HCO (7.5 and 15 µM) significantly inhibited the LPS-induced expression of inducible nitric oxide synthase. In addition, CO (1 and 5 µM) and 5-HCO (15 µM) markedly suppressed the production of prostaglandin E2 (PGE2) and expression of cyclooxygenase-2, a key enzyme in PGE2 synthesis, in LPS-stimulated macrophages. Moreover, CO treatment significantly reduced monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α) expression, whereas 5-HCO inhibited MCP-1, but not TNF-α expression. Both CO and 5-HCO inhibited the phosphorylation of inhibitor kappa B and transcriptional activation of nuclear factor kappa B (NF-κB) in LPS-stimulated macrophages. In addition, CO, but not 5-HCO, markedly reduced Akt phosphorylation. Taken together, these data suggest that CO, but not 5-HCO with a hydroxyethyl moiety on the D ring, has potent anti-inflammatory activity in LPS-stimulated macrophages through the downregulation of both the NF-κB and the Akt pathway.