Bioactive Phytochemicals of Acacia saligna.

Acacia saligna is native to Western Australia. It has become an introduced and fast-growing plant in other parts of the world due to its ability to adapt to drought, saline and alkaline soils, and hast growing environments. Studies on the bioactivities and phytochemicals of the plant extracts were conducted. However, comprehensive information that links those bioactivities to the identified compounds in the plant's extracts is still lacking. Data gathered in this review revealed a rich chemical diversity of hydroxybenzoic acids, cinnamic acids, flavonoids, saponins, and pinitols in A. saligna growing in Egypt, Saudi Arabia, Tunisia, South Africa, and Australia. The variability in phytochemical composition and quantity could be attributed to plant parts, growing locations, extraction solvents, and analysis methods. Identified phytochemicals support observed biological activities such as antioxidant, antimicrobial, anticancer, α-glucosidase inhibition, and anti-inflammation in the extracts. The knowledge of chemical structures, biological activities, and possible mechanisms of action of the bioactive phytochemicals identified in A. saligna were discussed. In addition, the structure-activity relationships of dominant active compounds were examined to explain the bioactivities exerted by A. saligna extracts. The review provides valuable insights towards future research and the development of new therapeutics from this plant.

Preventing Adipogenesis and Preserving Mitochondria and GLUT-4 Functions by Extracts and Isolated Compounds of Australian Acacia saligna.

Acacia saligna's secondary metabolites show promise in treating type 2 diabetes mellitus and its related conditions. We previously discovered that methanolic extracts, isolated flavonoids, and cyclitols effectively preserve mitochondria in 3T3-L1 adipocytes. In this current work, quantification of lipid droplet levels with Oil Red O assay showed a noticeable decrease in lipogenesis in 3T3-L1 cells. Methanolic leaf and bark extracts and isolated compounds, (-)-epicatechin 6 and myricitrin 8, reduced cellular lipid levels by 21.15% to 25.28%, respectively. mRNA levels of key regulators of mitochondrial biogenesis, such as adiponectin, PGC-1α, and mtTFA, were increased. Methanolic flower extract (FL-MeOH) and its chemical components, naringenin 1 and D-(+)-pinitol 5a, increased these gene levels from 10% to 29% at the higher dose. Our study found that FL-MeOH slightly reduced pro-inflammatory cytokines TNF-α and IL-6, attributed to two phytochemicals, naringenin-7-O-α-L-arabinofuranoside 2 and D-(+)-pinitol 5a. Western blot analysis also showed that adipocytes treated with MeOH extracts had higher GLUT-4 expression levels than untreated adipocytes. Overall, A. saligna extracts and their isolated compounds demonstrated anti-lipogenesis activity during 3T3-L1 cell differentiation, modulation of transcriptional levels of adiponectin, PGC-1α, and mtTFA, reducing TNF-α and IL-6 mRNA levels, promoting mitochondrial biogenesis, and enhancing GLUT-4 expression.

Identification of Phytochemicals in Bioactive Extracts of Acacia saligna Growing in Australia.

Acacia saligna growing in Australia has not been fully investigated for its bioactive phytochemicals. Sequential polarity-based extraction was employed to provide four different extracts from individual parts of A. saligna. Bioactive extracts were determined using in vitro antioxidant and yeast α-glucosidase inhibitory assays. Methanolic extracts from barks, leaves, and flowers are the most active and have no toxicity against 3T3-L1 adipocytes. Compound isolation of bioactive extracts provided us with ten compounds. Among them are two novel natural products; naringenin-7-O-α-L-arabinopyranoside 2 and (3S*,5S*)-3-hydroxy-5-(2-aminoethyl) dihydrofuran-2(3H)-one 9. D-(+)-pinitol 5a (from barks and flowers), (-)-pinitol 5b (exclusively from leaf), and 2,4-di-t-butylphenol 7 are known natural products and new to A. saligna. (-)-Epicatechin 6, quercitrin 4, and myricitrin 8 showed potent antioxidant activities consistently in DPPH and ABTS assays. (-)-Epicatechin 6 (IC50 = 63.58 µM),D-(+)-pinitol 5a (IC50 = 74.69 µM), and naringenin 1 (IC50 = 89.71 µM) are the strong inhibitors against the α-glucosidase enzyme. The presence of these compounds supports the activities exerted in our methanolic extracts. The presence of 2,4-di-t-butylphenol 7 may support the reported allelopathic and antifungal activities. The outcome of this study indicates the potential of Australian A. saligna as a rich source of bioactive compounds for drug discovery targeting type 2 diabetes.

Antihyperglycemic Properties of Extracts and Isolated Compounds from Australian Acacia saligna on 3T3-L1 Adipocytes.

Our early work indicated that methanolic extracts from the flowers, leaves, bark, and isolated compounds of Acacia saligna exhibited significant antioxidant activities in vitro. The overproduction of reactive oxygen species (ROS) in the mitochondria (mt-ROS) interfered with glucose uptake, metabolism, and its AMPK-dependent pathway, contributing to hyperglycemia and diabetes. This study aimed to screen the ability of these extracts and isolated compounds to attenuate the production of ROS and maintain mitochondrial function via the restoration of mitochondrial membrane potential (MMP) in 3T3-L1 adipocytes. Downstream effects were investigated via an immunoblot analysis of the AMPK signalling pathway and glucose uptake assays. All methanolic extracts effectively reduced cellular ROS and mt-ROS levels, restored the MMP, activated AMPK-α, and enhanced cellular glucose uptake. At 10 µM, (-)-epicatechin-6 (from methanolic leaf and bark extracts) markedly reduced ROS and mt-ROS levels by almost 30% and 50%, respectively, with an MMP potential ratio 2.2-fold higher compared to the vehicle control. (-)-Epicatechin 6 increased the phosphorylation of AMPK-α by 43%, with an 88% higher glucose uptake than the control. Other isolated compounds include naringenin 1, naringenin-7-O-α-L-arabinopyranoside 2, isosalipurposide 3, D-(+)-pinitol 5a, and (-)-pinitol 5b, which also performed relatively well across all assays. Australian A. saligna active extracts and compounds can reduce ROS oxidative stress, improve mitochondrial function, and enhance glucose uptake through AMPK-α activation in adipocytes, supporting its potential antidiabetic application.

Synthesis and biological evaluation of tetrahydroisoquinoline-derived antibacterial compounds.

Antibiotic resistance is one of the greatest threats to modern medicine. Drugs that were once routinely used to treat infections are being rendered ineffective, increasing the demand for novel antibiotics with low potential for resistance. Here we report the synthesis of 18 novel cationic tetrahydroisoquinoline-triazole compounds. Five of the developed molecules were active against S. aureus at a low MIC of 2-4 µg/mL. Hit compound 4b was also found to eliminate M. tuberculosis H37Rv at MIC of 6 µg/mL. This potent molecule was found to eliminate S. aureus effectively, with no resistance observed after thirty days of sequential passaging. These results identified compound 4b and its analogues as potential candidates for further drug development that could help tackle the threat of antibiotic resistance.

Novel Strategy for Non-Aqueous Bioconjugation of Substituted Phenyl-1,2,4-triazole-3,5-dione Analogues.

A novel 4-[4-(pentafluoro-λ6-sulfanyl)phenyl]-1,2,4-triazole-3,5-dione (5a) was synthesised as a potential [18F]radio-prosthetic group for radiolabelling peptides and proteins via selective bioconjugation with the phenolic side chains of tyrosine residues. Preliminary conjugation tests revealed the rapid hydrolysis of 5a under semi-aqueous conditions; these results led to further investigation into the electronic substituent effects of PTAD derivatives and corresponding hydrolytic stabilities. Five derivatives of 5a with para substituents of varying electron donating and withdrawing effects were synthesised for the investigation. The bioconjugation of these derivatives with model tyrosine was monitored in both aqueous and organic media in the presence of a variety of catalysts. From these investigations, we have found HFIP to be an effective catalyst when used in tandem with DCM as a solvent to give PTAD-tyrosine conjugate products (6a-f) in satisfactory to good yields (54-79%), whereas analogous reactions performed in acetonitrile were unsuccessful. The discovery of this system has allowed for the successful conjugation of electron-deficient PTAD derivatives to tyrosine, which would otherwise be unachievable under aqueous reaction conditions. The inclusion of these electron-deficient, fluorinated PTAD derivatives for use in the PTAD-tyrosine conjugation will hopefully broaden their applicability within fields such as 19F-MRI and PET imaging.

Synthesis and biological evaluation of 3,5-substituted pyrazoles as possible antibacterial agents.

The emergence of multi-drug resistant bacteria has increased the need for novel antibiotics to help overcome what may be considered the greatest threat to modern medicine. Here we report the synthesis of fifteen novel 3,5-diaryl-1H- pyrazoles obtained via one-pot cyclic oxidation of a chalcone and hydrazine-monohydrate. The synthesised pyrazoles were then screened against Staphylococcus aureus and Escherichia coli to determine their antibacterial potential. The results show that compound 7p is bacteriostatic at MIC 8 µg/mL. The compound is non-toxic against healthy mammalian cells, 3T3-L1 at the highest test concentration 50 µg/mL. Furthermore, compound 7p significantly affected bacterial morphogenesis before cell lysis in Bacillus subtilis when treated above the MIC concentration. From the results, a promising lead compound was identified for future development.

An Amine-Borane System Featuring Room-Temperature Dehydrogenation and Regeneration.

Amine-borane complexes have been extensively studied as hydrogen storage materials. Herein, we report a new amine-borane system featuring a reversible dehydrogenation and regeneration at room temperature. In addition to high purity H2 , the reaction between ethylenediamine bisborane (EDAB) and ethylenediamine (ED) leads to unique boron-carbon-nitrogen 5-membered rings in the dehydrogenation product where one boron is tricoordinated by three nitrogen atoms. Owing to the unique cyclic structure, the dehydrogenation product can be efficiently converted back to EDAB by NaBH4 and H2 O at room temperature. This finding could lead to the discovery of new amine boranes with potential usage as hydrogen storage materials.

Impact of A Cargo-Less Liposomal Formulation on Dietary Obesity-Related Metabolic Disorders in Mice.

Current therapeutic options for obesity often require pharmacological intervention with dietary restrictions. Obesity is associated with underlying inflammation due to increased tissue macrophage infiltration, and recent evidence shows that inflammation can drive obesity, creating a feed forward mechanism. Therefore, targeting obesity-induced macrophage infiltration may be an effective way of treating obesity. Here, we developed cargo-less liposomes (UTS-001) using 1,2-dioleoyl-sn-glycero-3-phosphocholine, DOPC (synthetic phosphatidylcholine) as a single-agent to manage weight gain and related glucose disorders due to high fat diet (HFD) consumption in mice. UTS-001 displayed potent immunomodulatory properties, including reducing resident macrophage number in both fat and liver, downregulating liver markers involved in gluconeogenesis, and increasing marker involved in thermogenesis. As a result, UTS-001 significantly enhanced systemic glucose tolerance in vivo and insulin-stimulated cellular glucose uptake in vitro, as well as reducing fat accumulation upon ad libitum HFD consumption in mice. UTS-001 targets tissue residence macrophages to suppress tissue inflammation during HFD-induced obesity, resulting in improved weight control and glucose metabolism. Thus, UTS-001 represents a promising therapeutic strategy for body weight management and glycaemic control.

Anti-HIV-1 protease activity of the crude extracts and isolated compounds from Auricularia polytricha.

BACKGROUND: Acquired immunodeficiency syndrome (AIDS) is caused by the Human immunodeficiency virus type-1 (HIV-1). HIV-1 protease (HIV-1 PR) is an essential enzyme for the HIV replication, and therefore, it is an important target for antiretroviral drugs development, particularly from natural products. Auricularia polytricha (AP) is an edible mushroom with several important therapeutic properties. These properties will be investigated as HIV-1 PR inhibitors. METHODS: The sequential hexane (APH), ethanol (APE) and water (APW) extracts from AP were screened for inhibitory activity against HIV-1 PR. The extract that consistently showed the strong HIV-1 PR inhibition was further investigated for its phytochemical constituents. The compounds were purified by column chromatography. The isolated compounds were structurally elucidated using 1D and 2D NMR, HRMS, FTIR, and GC/MS techniques. Each compound was screened against HIV-1 PR to determine its inhibitory activity and to provide an explanation for the activity found in the extract. RESULTS: Hexane crude extract of AP (APH) exhibited significant inhibition on HIV-1 PR activity. Four major compounds isolated from APH fraction were identified to be two triacylglycerols, linoleic acid and ergosterol. Moreover, all four compounds showed significant inhibition of HIV-1 PR activity. CONCLUSION: The findings from this study suggest that AP is a good source of fatty esters, fatty acids and ergosterol. These natural products exhibit anti-HIV-1 properties by blocking HIV-1 PR. These important biological results warrant further development of AP as an alternative antiretroviral drug.

Formation of an unexpected 3,3-diphenyl-3H-indazole through a facile intramolecular [2 + 3] cycloaddition of the diazo intermediate.

The one-pot reaction of 2,6-bis(diphenylmethyl)-4-methoxyaniline with tert-butylnitrite, BTEAC and DABSO in the presence of CuCl2 provided an unexpected 3H-indazole product 8. The structure of the compound was determined by HRMS, IR, NMR and further confirmed by single crystal X-ray crystallography. The compound crystallises in the triclinic P-1 space group, with unit cell parameters a = 9.2107 (4), b = 10.0413 (5), c = 14.4363 (6) Å, α = 78.183 (2), ß = 87.625 (2), γ = 71.975 (2)°. The formation of 8 proceeded through a facile intramolecular [2 + 3] cycloaddition of the diazo intermediate 9. The molecules of 8 are organised by edge-face Ar-H···π, face-face π···π, and bifurcated OCH2-H···N interactions. In addition to these, there are Ar-H···H-Ar close contacts, (edge-edge and surrounding inversion centres) arranged as infinite tapes along the a direction.

Acid-base fractions separated from Streblus asper leaf ethanolic extract exhibited antibacterial, antioxidant, anti-acetylcholinesterase, and neuroprotective activities.

BACKGROUND: Streblus asper is a well-known plant native to Southeast Asia. Different parts of the plant have been traditionally used for various medicinal purposes. However, there is very little scientific evidence reporting its therapeutic benefits for potential treatment of Alzheimer's disease (AD). The study aimed to evaluate antibacterial, antioxidant, acetylcholinesterase (AChE) inhibition, and neuroprotective properties of S. asper leaf extracts with the primary objective of enhancing therapeutic applications and facilitating activity-guided isolation of the active chemical constituents. METHODS: The leaves of S. asper were extracted in ethanol and subsequently fractionated into neutral, acid and base fractions. The phytochemical constituents of each fraction were analyzed using GC-MS. The antibacterial activity was evaluated using a broth microdilution method. The antioxidant activity was determined using DPPH and ABTS radical scavenging assays. The neuroprotective activity against glutamate-induced toxicity was tested on hippocampal neuronal HT22 cell line by evaluating the cell viability using MTT assay. The AChE inhibitory activity was screened by thin-layer chromatography (TLC) bioautographic method. RESULTS: The partition of the S. asper ethanolic leaf extract yielded the highest mass of phytochemical constitutions in the neutral fraction and the lowest in the basic fraction. Amongst the three fractions, the acidic fraction showed the strongest antibacterial activity against gram-positive bacteria. The antioxidant activities of three fractions were found in the order of acidic > basic > neutral, whereas the decreasing order of neuroprotective activity was neutral > basic > acidic. TLC bioautography revealed one component in the neutral fraction exhibited anti-AChE activity. While in the acid fraction, two components showed inhibitory activity against AChE. GC-MS analysis of three fractions showed the presence of major phytochemical constituents including terpenoids, steroids, phenolics, fatty acids, and lipidic plant hormone. CONCLUSIONS: Our findings have demonstrated the therapeutic potential of three fractions extracted from S. asper leaves as a promising natural source for neuroprotective agents with additional actions of antibacterials and antioxidants, along with AChE inhibitors that will benefit in the development of new natural compounds in therapies against AD.

Synthesis and in vitro biological evaluation of thiosulfinate derivatives for the treatment of human multidrug-resistant breast cancer.

Organosulfur compounds derived from Allium vegetables have long been recognized for various therapeutic effects, including anticancer activity. Allicin, one of the main biologically active components of garlic, shows promise as an anticancer agent; however, instability makes it unsuitable for clinical application. The aim of this study was to investigate the effect of stabilized allicin derivatives on human breast cancer cells in vitro. In this study, a total of 22 stabilized thiosulfinate derivatives were synthesized and screened for their in vitro antiproliferative activities against drug-sensitive (MCF-7) and multidrug-resistant (MCF-7/Dx) human adenocarcinoma breast cancer cells. Assays for cell death, apoptosis, cell cycle progression and mitochondrial bioenergetic function were performed. Seven compounds (4b, 7b, 8b, 13b, 14b, 15b and 18b) showed greater antiproliferative activity against MCF-7/Dx cells than allicin. These compounds were also selective towards multidrug-resistant (MDR) cells, a consequence attributed to collateral sensitivity. Among them, 13b exhibited the greatest anticancer activity in both MCF-7/Dx and MCF-7 cells, with IC50 values of 18.54±0.24 and 46.50±1.98 µmol/L, respectively. 13b altered cellular morphology and arrested the cell cycle at the G2/M phase. Additionally, 13b dose-dependently induced apoptosis, and inhibited cellular mitochondrial respiration in cells at rest and under stress. MDR presents a significant obstacle to the successful treatment of cancer clinically. These results demonstrate that thiosulfinate derivatives have potential as novel anticancer agents and may offer new therapeutic strategies for the treatment of chemoresistant cancers.

Mesoporous MnCo2O4 with a flake-like structure as advanced electrode materials for lithium-ion batteries and supercapacitors.

A mesoporous flake-like manganese-cobalt composite oxide (MnCo2O4) is synthesized successfully through the hydrothermal method. The crystalline phase and morphology of the materials are characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller methods. The flake-like MnCo2O4 is evaluated as the anode material for lithium-ion batteries. Owing to its mesoporous nature, it exhibits a high reversible capacity of 1066 mA h g(-1), good rate capability, and superior cycling stability. As an electrode material for supercapacitors, the flake-like MnCo2O4 also demonstrates a high supercapacitance of 1487 F g(-1) at a current density of 1 A g(-1), and an exceptional cycling performance over 2000 charge/discharge cycles.

Transformation of codeine and codeine-6-glucuronide to opioid analogues by urine adulteration with pyridinium chlorochromate: potential issue for urine drug testing.

RATIONALE: Pyridinium chlorochromate (PCC) is the active ingredient of 'Urine Luck', a commercially available in vitro adulterating agent used to conceal the presence of drugs in a urine specimen. The exposure of codeine and its major glucuronide metabolite codeine-6-glucuronide (C6G) to PCC was investigated to determine whether PCC is an effective masking agent for these opiate compounds. METHODS: Following the addition of PCC to both spiked and authentic codeine and C6G-positive urine specimens, the samples were monitored using liquid chromatography/mass spectrometry (LC/MS). Stable reaction products were identified and characterized using high-resolution MS analysis and, where possible, nuclear magnetic resonance (NMR) analysis. RESULTS: It was determined that PCC effectively oxidizes codeine and C6G, thus altering the original codeine-to-C6G ratio in the urine specimen. Four reaction products were identified for codeine: codeinone, 14-hydroxycodeinone, 6-O-methylcodeine and 8-hydroxy-7,8-dihydrocodeinone. Similarly, three reaction products were identified for C6G: codeinone, codeine and a lactone of C6G (tentative assignment). CONCLUSIONS: Besides addressing the complications added to interpretation, more investigation is warranted to further determine their potential for use as markers for monitoring the presence of codeine and C6G in urine specimens adulterated with PCC.

Cell-derived microparticles: new targets in the therapeutic management of disease.

Intercellular communication is essential to maintain vital physiological activities and to regulate the organism's phenotype. There are a number of ways in which cells communicate with one another. This can occur via autocrine signaling, endocrine signaling or by the transfer of molecular mediators across gap junctions. More recently communication via microvesicular shedding has gained important recognition as a significant pathway by which cells can coordinate the spread and dominance of selective traits within a population. Through this communication apparatus, cells can now acquire and secure a survival advantage, particularly in the context of malignant disease. This review aims to highlight some of the functions and implications of microparticles in physiology of various disease states, and present a novel therapeutic strategy through the regulation of microparticle production.

Inhibition of P-glycoprotein mediated multidrug resistance by stemofoline derivatives.

Resistance to chemotherapy in cancer patients has been correlated to the overexpression of the ATP-binding cassette (ABC) drug transporters including P-glycoprotein (P-gp) that actively efflux chemotherapeutic drugs from cancer cells. We examined the multidrug resistance reversing property of stemofoline derivatives in drug-resistance human cervical carcinoma (KB-V1) and human leukemic (K562/Adr) cell lines that overexpress P-gp. Didehydrostemofoline and eleven of its derivatives were synthesized and the cytotoxicity and their effect on doxorubicin, vinblastine and paclitaxel sensitivity in drug resistant (KB-V1 and K562/Adr) and drug sensitive (KB-3-1 and K562) cell lines by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay were determined. We found that three out of the twelve stemofoline derivatives including OH-A1, NH-B6 and NH-D6 showed commitment efficiency to increase sensitivity to doxorubicin, vinblastine and paclitaxel in KB-V1 cells and increase sensitivity to doxorubicin, and paclitaxel in K562/Adr cells whereas the effects have not been seen in their parental sensitive cancer cell lines (KB-3-1 and K562). These results indicate that stemofoline derivatives reversed P-gp-mediated multidrug resistance in vitro, and thus could be developed as effective chemosensitizers to treat multidrug-resistant cancers. The molecular mechanism of modulation of P-gp would be further determined.

Antidiabetic property of fractions and pure compounds from Andrographis paniculata.

Chlorophyll-free fractions of Andrographis paniculata were investigated for glucose uptake and lipid reduction in 3T3-L1 adipocytes. At 25 µg/ml, the acid fraction concentration enhanced glucose uptake by 82%. Basic and neutral fractions at 100 µg/ml enhanced glucose uptake by 82% and 78%, respectively. The three fractions showed improved glucose uptake compared to the crude extract (25% uptake at 50 µg/ml). GC-MS analysis of the fractions revealed the presence of chemicals with antidiabetic activities. The neutral fraction was prioritised for pure compound isolation to provide known andrographolide (1), 14-deoxyandrographolide (2), and a novel compound, 3-epi-11,12-didehydro-14-deoxyandrographolide (5). At a concentration of 1 µM, compounds 2 and 5 are as effective as 10 mM metformin in glucose uptake. They also reduce lipid accumulations in 3T3-L1 adipocytes by decreasing the size and number of lipid droplets. The activities of fractions and compounds support the use of A. paniculata in treating type 2 diabetes.

Ergosterol isolated from cloud ear mushroom (Auricularia polytricha) attenuates bisphenol A-induced BV2 microglial cell inflammation.

Bisphenol A (BPA) has been reported to have neurotoxic properties that may increase the risk of neurodegenerative diseases by inducing neuroinflammation. Auricularia polytricha (AP) is an edible mushroom with several medicinal properties. Herein, the anti-neuroinflammatory effects of AP extracts against BPA-induced inflammation of BV2 microglial cells were investigated. Hexane (APH) and ethanol (APE) extracts of AP inhibited BPA-induced neuroinflammation in BV2 microglia by reducing microglial activation and the expression of pro-inflammatory cytokines. These anti-inflammatory effects were regulated by the NF-κB signaling pathway. In addition, APH and APE exhibited antioxidative effects by increasing the activity of the SOD-1 enzyme and restoring the accumulation of reactive oxygen species (ROS) in BPA-induced BV2 cells. Moreover, the conditioned medium prepared using BPA-induced BV2 cells demonstrated that the presence of APH or APE could attenuate ROS production in HT-22 cells. Further, ergosterol was isolated from APE and also showed anti-inflammatory and antioxidative activities. In conclusion, AP extracts and ergosterol attenuated neuroinflammation against BPA induction in BV2 microglial cells through the NF-κB signaling pathway.

Phytochemical studies on Stemona aphylla: isolation of a new stemofoline alkaloid and six new stemofurans.

A new stemofoline alkaloid, (2'S)-hydroxy-(11S,12R)-dihydrostemofoline (3), new stemofurans M-R (8-13), and known compounds stemofoline (1), (2'S)-hydroxystemofoline (2), stemofuran E (4), stemofuran F (5), stemofuran J (6), and stilbostemin F (7) have been isolated from the root extracts of Stemona aphylla. The structures and relative configurations of these new compounds have been determined by spectroscopic data interpretation and from semisynthetic studies. These natural and semisynthetic alkaloids were tested for acetylcholinesterase inhibitory activities and were found to be 10-20 times less active than 1',2'-didehydrostemofoline itself. Stemofurans 4, 6, 8, 11, and 13 were tested for their antibacterial and antifungal activities. Three of these showed antibacterial activities against MRSA with MIC values of 15.6 µg/mL.