Chemical Composition and Chronic Toxicity of Disc-Cultured Antrodia cinnamomea Fruiting Bodies.

Antrodia cinnamomea (AC) is a popular fungus for use as folk medicine in health maintenance and disease prevention and treatment. Disc culture is a novel technique for producing AC fruiting bodies. This study aimed to investigate the bioactive components and toxicological properties of disc-cultured AC fruiting body powders (ACP) in rats. The HPLC technique was used to quantify the composition of bioactive triterpenoids in ACP. Toxicological properties were evaluated on male and female Sprague-Dawley rats receiving ACP orally at 200, 600, and 1000 mg/kg body weight for 90 days; the control group received only distilled water. The results show that ACP contained seven important AC index compounds, namely antcins A, B, C, K, and H, dehydrosulphurenic acid, and dehydroeburicoic acid. At the tested doses, oral ACP administration for 90 days caused no mortality, adverse effects on general health, body and organ weights, and food intake. Furthermore, no significant variations were observed in hematological and biochemical parameters among either sex of ACP-treated and control animals. An histopathological examination of vital organs showed no significant structural changes in organs, even in high-dose ACP-treated animals. This study indicated that ACP contained the major bioactive triterpenoids of AC fruiting bodies, and its no-observed-adverse-effect level (NOAEL) was 1000 mg/kg/day, about 20 times the recommended daily intake.

Antrodia cinnamomea and its compound dehydroeburicoic acid attenuate nonalcoholic fatty liver disease by upregulating ALDH2 activity.

ETHNOPHARMACOLOGICAL RELEVANCE: Nonalcoholic fatty liver disease (NAFLD) is a prevalent liver disease, but currently has no specific medication in clinic. Antrodia cinnamomea (AC) is a medicinal fungus and it has been shown that AC can inhibit high fat diet (HFD)-induced lipid deposition in mouse livers, but the effective monomer in AC and mechanism against NAFLD remain unclear. It has been reported that aldehyde dehydrogenase 2 (ALDH2) activation shows protective effects on NAFLD. Our previous study demonstrates that AC and its monomer dehydroeburicoic acid (DEA) can upregulate the ALDH2 activity on alcoholic fatty liver disease mouse model, but it is not clear whether the anti-NAFLD effects of AC and DEA are mediated by ALDH2. AIM TO STUDY: To elucidate the active compound in AC against NAFLD, study whether ALDH2 mediates the anti-NAFLD effects of AC and its effective monomer. MATERIALS AND METHODS: WT mice, ALDH2-/- mice and ALDH2-/- mice re-expressed ALDH2 by lentivirus were fed with a methionine-choline deficient (MCD) diet or high fat diet (HFD) to induce NAFLD, and AC at the different doses (200 and/or 500 mg/kg body weight per day) was administrated by gavage at the same time. Primary hepatocytes derived from WT and ALDH2-/-mice were stimulated by oleic acid (OA) to induce lipid deposition, and the cells were treated with AC or DEA in the meantime. Lentivirus-mediated ALDH2-KD or ALDH2-OE were used to knock down or overexpress ALDH2 expression in HepG2 cells, respectively. Finally, the effects of DEA against NAFLD as well as its effects on upregulating liver ALDH2 and removing the harmful aldehyde 4-hydroxynonenal (4-HNE) were studied in the MCD diet-induced NAFLD mouse model. RESULTS: In WT mice fed with a MCD diet or HFD, AC administration reduced hepatic lipid accumulation, upregulated ALDH2 activity in mouse livers, decreased 4-HNE contents both in mouse livers and serum, inhibited lipogenesis, inflammation and oxidative stress and promoted fatty acid ß-oxidation. These effects were abolished in ALDH2 KO mice but could be restored by re-expression of ALDH2 by lentivirus. In primary hepatocytes of WT mice, AC and DEA inhibited OA-induced lipid accumulation and triglyceride (TG) synthesis, promoting the ß-oxidation of fatty acid in the meantime. However, these effects were lost in primary hepatocytes of ALDH2 KO mice. Moreover, the expression level of ALDH2 significantly affected the inhibitory effects of AC and DEA on OA-induced lipid deposition in HepG2 cells. The effects of AC and DEA on suppressing lipid deposition, inhibiting mitochondrial ROS levels, reducing TG synthesis, and promoting ß-oxidation of fatty acid were all enhanced with the overexpression of ALDH2 and reduced with the knockdown of ALDH2 expression. DEA showed dose-dependent effects on inhibiting liver lipid deposition, elevating ALDH2 activity and reducing 4-HNE levels in the livers of MCD diet-induced NAFLD mice. CONCLUSION: DEA is the effective compound in AC against NAFLD. The related anti-NAFLD mechanisms of AC and DEA were through upregulating ALDH2 expression and activity, thus enhancing the elimination of 4-HNE in the livers, and sequentially alleviating oxidative stress and inflammation, promoting fatty acid ß-oxidation and decreasing lipogenesis.

Potential natural products that target the SARS-CoV-2 spike protein identified by structure-based virtual screening, isothermal titration calorimetry and lentivirus particles pseudotyped (Vpp) infection assay.

BACKGROUND AND AIM: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters cells through the binding of the viral spike protein with human angiotensin-converting enzyme 2 (ACE2), resulting in the development of coronavirus disease 2019 (COVID-19). To date, few antiviral drugs are available that can effectively block viral infection. This study aimed to identify potential natural products from Taiwan Database of Extracts and Compounds (TDEC) that may prevent the binding of viral spike proteins with human ACE2 proteins. METHODS: The structure-based virtual screening was performed using the AutoDock Vina program within PyRX software, the binding affinities of compounds were verified using isothermal titration calorimetry (ITC), the inhibitions of SARS-CoV-2 viral infection efficacy were examined by lentivirus particles pseudotyped (Vpp) infection assay, and the cell viability was tested by 293T cell in MTT assay. RESULTS AND CONCLUSION: We identified 39 natural products targeting the viral receptor-binding domain (RBD) of the SARS-CoV-2 spike protein in silico. In ITC binding assay, dioscin, celastrol, saikosaponin C, epimedin C, torvoside K, and amentoflavone showed dissociation constant (K d) = 0.468 µM, 1.712 µM, 6.650 µM, 2.86 µM, 3.761 µM and 4.27 µM, respectively. In Vpp infection assay, the compounds have significantly and consistently inhibition with the 50-90% inhibition of viral infection efficacy. In cell viability, torvoside K, epimedin, amentoflavone, and saikosaponin C showed IC50 > 100 µM; dioscin and celastrol showed IC50 = 1.5625 µM and 0.9866 µM, respectively. These natural products may bind to the viral spike protein, preventing SARS-CoV-2 from entering cells. SECTION 1: Natural Products. TAXONOMY CLASSIFICATION BY EVISE: SARS-CoV-2, Structure-Based Virtual Screening, Isothermal Titration Calorimetry and Lentivirus Particles Pseudotyped (Vpp) Infection Assay, in silico and in vitro study.

Characterization Of Secondary Metabolites From The Rhizome Of Cynara Scolymus And Their Antioxidant Properties.

The aerial portions of Cynara scolymus commonly have been eaten as vegetables or functional foods by the people lived in Mediterranean region. In preliminary antioxidant screening, the rhizome portions (CSR) of this species showed better potential than leaves ones. However, neither phytochemical nor pharmacology studies of CSR have been reported to date. The purpose of this research was to identify the active components from CSR through bioassay-guided fractionation. The antioxidant properties of secondary metabolites 1-9 were evaluated in this investigation. Compounds 4-6, 8, and 9 showed antioxidant activities based on DPPH free radical scavenging activity with IC50 values of 22.91-147.21 µM. Besides, compound 8 significantly and dose-dependently reduced H2O2-induced ROS levels in keratinocyte HaCaT cells without cytotoxicity toward HaCaT. Overall, our studies demonstrated the rhizome of C. scolymus could be used as a new natural antioxidant like the edible aerial portions and phenolic compounds are the active components.

Antrodia cinnamomea, a Treasured Medicinal Mushroom, Induces Growth Arrest in Breast Cancer Cells, T47D Cells: New Mechanisms Emerge.

Reported cases of breast cancer have skyrocketed in the last decades with recent advances in examination techniques. Brest cancer has become the second leading cause of mortality among women worldwide, urging the scientific community to develop or find new drugs from natural sources with potent activity and a reasonable safety profile to tackle this ailment. Antrodia cinnamomea (AC) is a treasured medicinal fungus which has attracted attention due to its potent hepatoprotective and cytotoxic activities. We evaluated the antiproliferative activity of the ethanol extract of artificially cultured AC (EEAC) on breast cancer cells (T47D cells) in vivo and in vitro. Ethanol extract of artificially cultured AC inhibited T47D cells' proliferation mediated by cell cycle arrest at G1 phase as well induced autophagy. Immunoblotting assay confirmed that EEAC not only decreased the expression of the cell-cycle-related proteins but also increased the expression of transcription factor FOXO1, autophagic marker LC3 II, and p62. Ethanol extract of artificially cultured AC mediated endoplasmic reticulum stress by promoting the expression of IRE1 (inositol-requiring enzyme 1α), GRP78/Bip (glucose regulating protein 78), and CHOP (C/EBP homologous protein). Apart from previous studies, HDACs (histone deacetylases) activity was inhibited as demonstrated by a cell-free system, immunoblotting, and immunofluorescence assays following EEAC treatment. The in vivo studies demonstrated that EEAC decreased tumor volume and inhibited tumor growth without any significant side effects. High performance liquid chromatography profile demonstrated similar triterpenoids compared to the profile of wild AC ethanol extract. The multiple targets of EEAC on breast cancer cells suggested that this extract may be developed as a potential dietary supplement targeting this debilitating disease.

Targeted and non-targeted analysis of annonaceous alkaloids and acetogenins from Asimina and Annona species using UHPLC-QToF-MS.

In current work, targeted and non-targeted analysis of alkaloids and acetogenins from methanolic extracts of Asimina, Annona species and dietary supplements have been performed using UHPLC-QToF in positive ion mode. Thirty-five standard compounds (twelve alkaloids and twenty-three acetogenins) were used for the analysis. The fragment ions produced by collision induced dissociation (CID) revealed the characteristic cleavage and provided structural information. Aporphine alkaloids and acetogenins are the major groups found in Asimina and Annona species. An untargeted analysis based on high-resolution mass spectrometry was carried out to profile the alkaloids and acetogenins from Asimina species (As. triloba, As. parviflora). Magnoflorine, being a major alkaloid from twigs of As. triloba samples, was used as an example to discuss the fragmentation patterns. In (+)-ESI-MS, magnoflorine gave [M]+ ions at m/z 342.1705. The fragment ions at m/z 297.1127 [M-(CH3)2NH]+, 282.0886 [M-(CH3)3NH]+, 265.0865 [M-(CH3)2NH-CH3OH]+, 237.0916 [M-(CH3)2NH-CH3OH-CO]+, and 222.0681 [M-(CH3)2NH-CH3OH-CO-CH3]+ resulted from the [M]+ molecular ion. One dietary supplement claiming to contain paw paw (As. triloba) was also analyzed and showed a similar profile to twigs of As. triloba. A total of 131 compounds including standard compounds were identified from the different parts of As. triloba and As. parviflora samples. These compounds can be used to distinguish Asimina species. However, for definite identification of these unknown components, further investigation is required. This may provide a model for the rapid screening and structural characterization of bioactive constituents from plant extracts in a single analysis.

Anti-allergic Hydroxy Fatty Acids from Typhonium blumei Explored through ChemGPS-NP.

Increasing prevalence of allergic diseases with an inadequate variety of treatment drives forward search for new alternative drugs. Fatty acids, abundant in nature, are regarded as important bioactive compounds and powerful nutrients playing an important role in lipid homeostasis and inflammation. Phytochemical study on Typhonium blumei Nicolson and Sivadasan (Araceae), a folk anti-cancer and anti-inflammatory medicine, yielded four oxygenated fatty acids, 12R-hydroxyoctadec-9Z,13E-dienoic acid methyl ester (1) and 10R-hydroxyoctadec-8E,12Z-dienoic acid methyl ester (2), 9R-hydroxy-10E-octadecenoic acid methyl ester (3), and 12R*-hydroxy-10E-octadecenoic acid methyl ester (4). Isolated compounds were identified by spectroscopic methods along with GC-MS analysis. Isolated fatty acids together with a series of saturated, unsaturated and oxygenated fatty acids were evaluated for their anti-inflammatory and anti-allergic activities in vitro. Unsaturated (including docosahexaenoic and eicosapentaenoic acids) as well as hydroxylated unsaturated fatty acids exerted strong anti-inflammatory activity in superoxide anion generation (IC50 2.14-3.73 µM) and elastase release (IC50 1.26-4.57 µM) assays. On the other hand, in the anti-allergic assays, the unsaturated fatty acids were inactive, while hydroxylated fatty acids showed promising inhibitory activity in A23187- and antigen-induced degranulation assays (e.g., 9S-hydroxy-10E,12Z-octadecadienoic acid, IC50 92.4 and 49.7 µM, respectively). According to our results, the presence of a hydroxy group in the long chain did not influence the potent anti-inflammatory activity of free unsaturated acids. Nevertheless, hydroxylation of fatty acids (or their methyl esters) seems to be a key factor for the anti-allergic activity observed in the current study. Moreover, ChemGPS-NP was explored to predict the structure-activity relationship of fatty acids. The anti-allergic fatty acids formed different cluster distant from clinically used drugs. The bioactivity of T. blumei, which is historically utilized in folk medicine, might be related to the content of fatty acids and their metabolites.

Anti-inflammatory Cerebrosides from Cultivated Cordyceps militaris.

Cordyceps militaris (bei-chong-chaw, northern worm grass) is a precious and edible entomopathogenic fungus, which is widely used in traditional Chinese medicine (TCM) as a general booster for the nervous system, metabolism, and immunity. Saccharides, nucleosides, mannitol, and sterols were isolated from this fungus. The biological activity of C. militaris was attributed to the saccharide and nucleoside contents. In this study, the aqueous methanolic fraction of C. militaris fruiting bodies exhibited a significant anti-inflammatory activity. Bioactivity-guided fractionation of the active fraction led to the isolation of eight compounds, including one new and two known cerebrosides (ceramide derivatives), two nucleosides, and three sterols. Cordycerebroside A (1), the new cerebroside, along with soyacerebroside I (2) and glucocerebroside (3) inhibited the accumulation of pro-inflammatory iNOS protein and reduced the expression of COX-2 protein in LPS-stimulated RAW264.7 macrophages. This is the first study on the isolation of cerebrosides with anti-inflammatory activity from this TCM.

Use, history, and liquid chromatography/mass spectrometry chemical analysis of Aconitum.

Aconitum and its products have been used in Asia for centuries to treat various ailments, including arthritis, gout, cancer, and inflammation. In general, their preparations and dispensing have been restricted to qualified folk medicine healers due to their low safety index and reported toxicity. In the past few decades, official guidelines have been introduced in Asian pharmacopeias to control Aconitum herbal products. However, these guidelines were based on primitive analytical techniques for the determination of the whole Aconitum alkaloids and were unable to distinguish between toxic and nontoxic components. Recent advances in analytical techniques, especially high performance liquid chromatography (HPLC) and electrophoresis coupled with highly sensitive detectors, allowed rapid and accurate determination of Aconitum secondary metabolites. Reports focusing on liquid chromatography/mass spectrometry analysis of Aconitum and its herbal products are discussed in the current review. This review can be used by the health regulatory authorities for updating pharmacopeial guidelines of Aconitum and its herbal products.

Acetogenins from Annonaceae.

In recent decades, annonaceous acetogenins have become highly studied plant secondary metabolites in terms of their isolation, structure elucidation, synthesis, biological evaluation, mechanism of action, and toxicity. The aim of the present contribution is to summarize chemical and biological reports published since 1997 on annonaceous acetogenins and synthetic acetogenin mimics. The compounds are considered biologically in terms of their cytotoxicity for cancer cell lines, neurotoxicity, pesticidal effects, and miscellaneous activities.

Clinical Aspects of Aconitum Preparations.

Aconite species have played an important role in human history. Aconitum species have been used worldwide as poisons as well as remedies. Their potential in targeting several ailments such as pain, rheumatism, and lethargy has been recognized by Western, Chinese, and Indian health care practitioners. Aconite use in herbal preparations has declined, especially in Europe and the United States, in the first half of the twentieth century due to several reported toxicity cases. The situation has changed with the application of new technologies for the accurate analysis of its toxic components and the development of efficient detoxification protocols. Some Asian countries started small clinical trials to evaluate the potency and safety of different marketed aconite preparations. The current review summarizes therapeutic uses of aconite preparations in China, Taiwan, India, and Japan. It also highlights clinical trial results with special emphasis on their limitations. Modern drugs and pharmacopoeial preparations derived from aconite are also discussed.

Alkylamides of Acmella oleracea.

Phytochemical investigation of the flowers of Acmella oleracea had resulted in the isolation of one new alkylamide, (2E,5Z)-N-isobutylundeca-2,5-diene-8,10-diynamide (1), together with four known analogues (2-5). The structures of these compounds were determined by the interpretation of spectroscopic methods, especially NMR technologies (COSY, HSQC, HMBC, and NOESY). In addition, a convenient method for concentrating the alkylamide-rich fraction and analyzing fingerprint profile of A. oleracea was established.

Fast quantification of S-adenosyl-L-methionine in dietary health products utilizing reversed-phase high-performance liquid chromatography: teaching an old method new tricks.

S-adenosyl-L-methionine is a ubiquitous methyl donor in living bodies. It is known to participate in several physiological processes including homocysteine metabolism and glutathione synthesis regulation, and cellular antioxidant mechanism. S-adenosyl-L-methionine containing dietary supplements has been prescribed recently for the treatment of depression, arthritis, and liver diseases with encouraging results. The development of an efficient analytical protocol for S-adenosyl-L-methionine containing dietary supplements is crucial for maintaining product quality and consumer health. In this study, the S-adenosyl-L-methionine content of several yeast products and commercial healthy food product samples was quantitatively analyzed utilizing HPLC. The chromatographic separation was achieved on a reversed-phase column and 2 % acetonitrile with a 98 % ammonium-acetate mobile phase under pH 4.5, with a flow rate of 1.0 mL/min. The wavelength used for detection with the UV detector was 254 nm. The total analysis time was short and the target compound showed a well-defined peak. The correlation coefficient of the regression curve showed good linearity and sensitivity with r = 0.999. All experiments were replicated five times and the relative standard deviations as well as the relative error values were all less than 3 %. Moreover, the achieved precision and accuracy values were high with 97.4-100.9 % recovery. Qualitative determination of S-adenosyl-L-methionine in the tested products was achieved using NMR and LC-MS techniques. The developed protocol is robust, fast, and suitable for the quality control analysis of yeast and commercial S-adenosyl-L-methionine products.

Recent research and development of Antrodia cinnamomea.

Medicinal mushrooms have attracted much attention recently owing to their potent therapeutic activity, especially as chemopreventive and immunomodulatory agents. Antrodia cinnamomea is a treasured Taiwanese mushroom that has been used by aboriginal tribes for centuries to treat food intoxication and to enhance liver functions. It was included in Asian folk medicine in the last few decades with remarkable results in treating inflammatory disorders, cancers, hypertension and hepatitis. This myriad of therapeutic activities encouraged several research groups to subject A. cinnamomea to intensive biological and phytochemical investigation, leading to the isolation of different classes of pharmacologically active secondary metabolites. The in vitro and in vivo biological results of the mushroom extracts and its active components revealed their potent cytotoxic, anti-inflammatory and hepatoprotective activities. The aim of this study is to review recent reports on the biological activities of A. cinnamomea extracts and its active components; quality control protocols; synthetic methodologies for the preparation of active components; developed culture techniques; phylogenetic analysis and gene cloning. This study also tackles major challenges facing future expansion of A. cinnamomea production.

Antileukemia component, dehydroeburicoic acid from Antrodia camphorata induces DNA damage and apoptosis in vitro and in vivo models.

Antrodia camphorata (AC) is a native Taiwanese mushroom which is used in Asian folk medicine as a chemopreventive agent. The triterpenoid-rich fraction (FEA) was obtained from the ethanolic extract of AC and characterized by high performance liquid chromatography (HPLC). FEA caused DNA damage in leukemia HL 60 cells which was characterized by phosphorylation of H2A.X and Chk2. It also exhibited apoptotic effect which was correlated to the enhancement of PARP cleavage and to the activation of caspase 3. Five major triterpenoids, antcin K (1), antcin C (2), zhankuic acid C (3), zhankuic acid A (4), and dehydroeburicoic acid (5) were isolated from FEA. The cytotoxicity of FEA major components (1-5) was investigated showing that dehydroeburicoic acid (DeEA) was the most potent cytotoxic component. DeEA activated DNA damage and apoptosis biomarkers similar to FEA and also inhibited topoisomerase II. In HL 60 cells xenograft animal model, DeEA treatment resulted in a marked decrease of tumor weight and size without any significant decrease in mice body weights. Taken together, our results provided the first evidence that pure AC component inhibited tumor growth in vivo model backing the traditional anticancer use of AC in Asian countries.

Chemical profiling of the cytotoxic triterpenoid-concentrating fraction and characterization of ergostane stereo-isomer ingredients from Antrodia camphorata.

Antrodia camphorata (AC), also known as Antrodia cinnamomea, an endemic species in Taiwan, is one of the treasured medicinal mushrooms. AC is traditionally used for its chemopreventive biofunctions. In this investigation, we report a convenient method for concentrating the antiproliferative active triterpenoid-rich fraction (FEA), from ethanolic extract of AC (EEAC). A series of stereo-isomers of zhankuic acids (1-8) from the FEA was purified by HPLC using an efficient acidic solvent system. The structures of compounds 1-8 were elucidated based on spectroscopic data analysis, and the absolute configuration of α-chiral carboxylic acid at C-25 in the structures was assigned based on reaction with (R)- and (S)-1-(9-anthryl)-2,2,2-trifluoroethanol. Major ingredients of FEA (eight ergostanes 1-8 and two lanostanes 9-10) were further characterised by high-performance liquid chromatography-photodiode array detection/mass spectrometry (HPLC-PDA/MS). Compounds 1-8 and their pair mixture forms (antcin K, antcin C, zhankuic acid C, and zhankuic acid A) were subjected to anti-proliferative assay against three human leukemia cell lines. Among them, the derivatives with carbonyl group at C-3 showed cytotoxicity with IC(50) values ranging from 16.44 to 77.04 µg/ml.

Annonacin induces cell cycle-dependent growth arrest and apoptosis in estrogen receptor-α-related pathways in MCF-7 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Tamoxifen resistance is common in estrogen receptor-α (ERα)-positive breast cancers. Pawpaw and soursop are anticancer annonaceous plants in complementary medicine. Thus, we studied the effects of annonacin, an annonaceous acetogenin, in breast cancer cells. MATERIALS AND METHODS: Cell growth and ERα-related pathways were studied. The effects of annonacin were tested in MCF-7 xenografts in nude mice. RESULTS: In ERα-positive MCF-7 cells, annonacin (half-effective dose ED(50) = 0.31 µM) and 4-hydroxytamoxifen (ED(50) = 1.13 µM) decreased cell survival whereas annonacin (0.5-1 µM) increased cell death at 48 h. Annonacin and 4-hydroxytamoxifen were additive in inhibiting cell survival. Annonacin (0.1 µM) induced G(0)/G(1) growth arrest while increasing p21(WAF1) and p27(kip1) and decreasing cyclin D1 protein expression. Annonacin (0.1µM) decreased cyclin D1 protein expression more than 4-hydroxytamoxifen (1 µM). Annonacin (0.1 µM) increased apoptosis while decreasing Bcl-2 protein expression. The combination of annonacin (0.1 µM) and 4-hydroxytamoxifen (1 µM) decreased Bcl-2 protein expression and ERα transcriptional activity more than annonacin (0.1 µM) did alone. Annonacin, but not 4-hydroxytamoxifen, decreased ERα protein expression. Moreover, annonacin decreased phosphorylation of ERK1/2, JNK and STAT3. In nude mice, annonacin decreased MCF-7 xenograft tumor size at 7-22 days. Moreover, annonacin decreased ERα, cyclin D1 and Bcl-2 protein expression in the xenograft at 22 days. CONCLUSIONS: Annonacin induced growth arrest and apoptosis in ERα-related pathways in MCF-7 cells. Annonacin and 4-hydroxytamoxifen were additive in inhibiting cell survival and ERα transcriptional activity. Moreover, annonacin attenuated MCF-7 xenograft tumor growth while inhibiting ERα, cyclin D1 and Bcl-2 protein expressions in nude mice.

Historic perspectives on Annonaceous acetogenins from the chemical bench to preclinical trials.

Studies on the Annonaceous acetogenins began after the first cytotoxic acetogenin, uvaricin, was isolated in 1982. This attractive finding made many medicinal and natural product chemists direct their efforts on the isolation and identification of these classes of compounds. As more Annonaceous acetogenins were isolated, more information about them was uncovered. From their structural identification to the total synthesis of natural product analogues and from cell-based screening and molecular-based targeting to animal testing, the mechanisms of action of the Annonaceous acetogenins became clearer. The purpose of this review is to give an account of recent studies on this class of compounds and their analogues, which will aid us not only in clarifying how the Annonaceous acetogenins act but also in establishing principles for the further development of this class of compounds.

Constituents of Polyalthia longifolia var. pendula.

Three new clerodane-type diterpenes, 6alpha,16-dihydroxycleroda-3,13-dien-15-oic acid (1), 6alpha,16-dihydroxycleroda-4(18),13-dien-15-oic acid (2), and 4alpha,18beta-epoxy-16-hydroxyclerod-13-en-15-oic acid (3), and four new protoberberine alkaloids, (-)-8-oxo-10-hydroxy-2,3,9-trimethoxyberberine (4), (-)-8-oxo-2,11-dihydroxy-3,10-dimethoxyberberine (5), (-)-8-oxo-11-hydroxy-2,3,9,10-tetramethoxyberberine (6), and (-)-8-oxo-2,10-dihydroxy-3,9,11-trimethoxyberberine (7), together with 11 known substances, were isolated from a methanol extract of the stems of Polyalthia longifolia var. pendula. The structures of 1-7 were elucidated on the basis of spectroscopic data analysis. Compounds were evaluated for their antiproliferative activities against A549 and MCF-7 cancer cells, and among the substances tested, only 16-oxo-cleroda-3,13-dien-15-oic acid (8) exhibited cytotoxicity.