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Abstract: COVID-19, or SARS-CoV-2, is an extremely deadly virus that is responsible for over half a million deaths of people in the world. This virus originated in China in December 2019 and rapidly spread worldwide in 2-3 months, and affected every part of the world. Its life-threatening nature forced governments in all countries to take emergency steps of lockdown that affected the entire world's education, health, social and economic aspects. Due to the implementation of these emergencies, the population is facing psychological, social and financial problems. Additionally, this pandemic has significantly influenced the health care systems as all the resources from governments of all countries were directed to invest funds to discover new diagnostic tests and manage COVID-19 infection. The impact of the COVID-19 pandemic on the education and social life of the population is described in this article. Additionally, the diagnosis, management, and phytoremediation to control the spread of COVID-19 and traditional medicinal plants' role in managing its mild symptoms have been discussed.

Alzheimer's disease (AD), a relentless neurodegenerative disorder, is still waiting for safer profile drugs, risk factors affecting AD's pathogenesis include aβ accumulation, tau protein hyperphosphorylation, and neuroinflammation. This research aimed to synthesize 2-amino-6‑trifluoromethoxy benzothiazole schiff bases. Synthesis was straightforward, combining the riluzole skeleton with compounds containing the azomethine group. Schiff bases synthesized were characterized spectroscopically using proton NMR (

Chemical studies on

Athyrium plants consist of more than 230 species that are largely distributed in the Sino-Himalayan region and the Western Pacific islands. Athyrium species are being used in traditional medicine worldwide to treat various ailments such as cough, rheumatic pain, scorpion stings, sores, burns and scalds, intestinal fever, pain, specifically breast pain during child birth, to increase milk flow, as an antiparasitic, anthelmintic, and carminative. A deep look in the literature has revealed that Athyrium species have been poorly investigated for their food preservative applications and in vivo and in vitro biological and phytochemical studies. However, some Athyrium species have demonstrated antimicrobial, anti-inflammatory, antioxidant, antiproliferative and anti-HIV potential. Athyrium multidentatum (Doll.) Ching is the most investigated species and the biological activities of their extracts, such as they antioxidant properties, seem to be related to the sulfate contents of their polysaccharides. This review provides an update on the ethnopharmacology, phytochemistry and biological properties of Athyrium plants that might be useful for further research. Of course, well-designed clinical trials will be required for some species to be used as therapy. Keywords: Athyrium, Ethnobotany, Ethnopharmacology, Biological activities, Phytoconstituents

Objective The detailed knowledge about protective effects of capsaicin (cap) and involved mechanisms against testicular torsion (TT) is still not available completely. Methods Male Wistar rats were assigned into four major cohorts: (i) sham, (ii) TT, (iii) three subgroups subjected to TT and different doses of cap (100, 500, and 1000 µg/mL), and (iv) three subgroups of healthy animals subjected to various concentrations of cap. The animals were decapitated at 24 h after reperfusion, and the evaluation of protein expression was performed by Western blotting assay. At 72 h after reperfusion, apoptotic cell death and tissue injury were evaluated by TUNEL nuclear and H&E staining, respectively. Results The results showed that cap administration following TT significantly increased the expression of tuberous sclerosis proteins 1 and 2 (Tsc1/Tsc2) in a dose-dependent manner (P Conclusion Collectively, our findings demonstrate the validity of cap as a therapeutic agent against TT through targeting Tsc1/Tsc2 in a dose-dependent manner.

Hypoxia-inducible factor-1 is a target for the management of cancer. Here, the anti-proliferation properties of corosolic acid (CA) against A549 human lung epithelial cancer cells in CoCl2-induced hypoxia is reported. CA was isolated from the roots of Salvia syriaca based on a bioassay-guided isolation platform and identified by 1D and 2D NMR experiments. Several cytotoxicies and genotoxicity analyses were performed using MTT, DAPI, cell cycle, DNA ladder, and annexin V/PI detection. Cobalt chloride (CoCl2) was used to stimulate hypoxia. The adaptation of A549 cells to a stimulated hypoxic condition in the presence of CA was evaluated. CA decreased the growth of A549 cells with an IC50 of 12 μg/mL at 48 h. Also, chromatin condensation and DNA fragmentation were detected as signs of apoptosis occurrence. CA induced ~85% apoptosis and even 1% necrosis. The expression of hypoxia-inducible factor-1 α (HIF-1α), HIF-1β and downstream genes was strongly suppressed in the presence of CA in CoCl2-stimulated hypoxia condition. Results indicated that CA has remarkable cytotoxicity against the cancerous cell in hypoxia condition and may be regarded for preparation of new formulations for possible uses as supplement and medicine in cancer therapy.

Background Thymus genus has been used since ancient times for their valuable health properties, which could be attributed to their chemical components, especially essential oils (EOs). Among these species, T. vulgaris has a long history of use for different food and medicinal purposes. Scope and approach This paper reviews the chemical composition of Thymus plants EOs, including thyme, describes their antimicrobial and antioxidant properties as well as recent food applications as preservatives. The role of these plants in cancer is also covered, as well as the potential these plants have to manage and treat other diseases. Furthermore, clinical studies are also detailed. Key findings and conclusions Food preservation with naturally occurring compounds is gaining increasing importance due to the consumer demand for safe and high-quality products and to reduce the use of synthetic preservatives. For this purpose, not only thyme but also other thymus plants can be used as such and combined with high-pressure, cold nitrogen plasma, in edible films (active packaging), etc. Moreover, the potential of these plants have to treat several diseases and complications reinforce their use in nutraceuticals and functional foods, but further clinical evidence is required.

Nine novel fused indolo [1,8] naphthyridine derivatives were synthesized using the Povarov reaction, in a one-pot system, and were fully characterized by spectroscopic techniques such as FT-IR, NMR...

Chemical studies on Acanthaster planci have afforded two steroids, 5α-cholesta-24-en-3β,20β-diol-23-one (1) and 5α-cholesta-9(11)-en-3β, 20β-diol (2). Structures compounds 1 and 2 were determined with the help of spectroscopic studies. Compound 1 showed strong antibacterial activity (21.0 ± 0.06 mm) against P. aeruginosa. Compounds 1 and 2 were also active against human breast carcinoma cells (MCF-7) with LC50 values of 49 ± 1.6 and 57.5 ± 1.5 μg/ml, respectively. This bioactivity was comparable to the currently used anticancer agent, cisplatin (LC50 46 ± 1.1 µg/ml). Compounds 1 and 2 exhibited anti-α-glucosidase activity with IC50 values of 58 ± 0.8 and 55 ± 0.5 µg/ml, respectively, whereas IC50 of Acarbose as a positive control was found to be 36 ± 0.4 µg/ml in our bioassay.

A straightforward approach toward the assembly of phenanthridinone heterocycles has been developed through the palladium-catalyzed N-benzylation/intramolecular coupling reactions of readily prepared 4-quinolones with commercially available 2-bromobenzyl bromide derivatives. The target products were prepared in moderate to good yields, with tolerance of various functional groups.

A new class of pyrazolo[4,3-c]quinoline (5a-i, 7a-b) and pyrano[3,2-c]quinoline (9a-i) derivatives were designed and synthesized in moderate to good yields by microwave conditions. To enhance the yield of pyrano[3,2-c]quinoline derivatives, multicomponent one-pot synthesis has been developed. The synthesized compounds were identified by spectral and elemental analyses. Compounds 9a and 9i showed good antibacterial activity against Gram-positive and Gram-negative bacterial strains. All of the new compounds exhibited weak to moderate antioxidant activity, compound 9d exerted significant antioxidant power. The cytotoxicity of these compounds were also evaluated against MCF-7 (breast) and A549 (Lung) cancer cell lines. Most of the compounds displayed moderate to good cytotoxic activity against these cell lines. Compound 9i was found to be significantly active in this assay and also induced cell death by apoptosis. Molecular docking studies were carried out using EGFR inhibitor in order to determine the molecular interactions.

Nine novel fused indolo [1,8] naphthyridine derivatives were synthesized using the Povarov reaction, in a one-pot system, and were fully characterized by spectroscopic techniques such as FT-IR, NMR, TOF-MS, and elemental analysis. Furthermore, their antibacterial activities against six bacterial strains were assessed. The results of the bioassay demonstrated that compounds 4a, 4c, and 4i showed good inhibitory effect with a MIC value ranging from 0.04687 to 0.09375 µM against Bacillus cereus and Staphylococcus aureus. The toxicity of 4a-i, evaluated through mutagenicity test against Salmonella typhimurium TA 98 and TA100 strains, revealed that there was no significant increase in the number of revertant colonies in comparison with the control, sodium azide.

A simple and short approach for the synthesis of pyrazolo[3,4-b]quinoline (3a–3p) and pyrazolo[4,3-c]quinoline (6a–6 h) using various Lewis acid catalysts was developed. InCl3 was found to be more effective in providing greater yield of products compared to Yb(OTf)3, Sc(OTf)3, SnCl4, AlCl3, TiCl4, ZnCl2, FeCl3, and BF3 · Et2O. Moreover, a comparison of conventional and microwave methods has revealed that the latter method is more efficient compared to former one. Structures were confirmed by Fourier transform infrared, mass spectrometry, 1H and 13C NMR, X-ray crystallography, and elemental analyses. All of the synthesized compounds were evaluated for α-glucosidase inhibitory activity. Compounds 3a, 3p, 3i, 3 h, 3k, 3o, and 3 g exhibited anti α-glucosidase inhibitory activity with IC50 values of 57.5, 60.3, 65.9, 71.9, 80.8, 123.7, and 126.4 µM, respectively, which is quite comparable to the standard drug acarbose (IC50 = 115.8 µM).

Based on the existing structure activity relationship for proteasome inhibitors, a number of substituted aryl-2-nitrovinyl derivatives have been synthesized as Michael acceptor and their cytotoxicity and proteasome inhibitory effects were evaluated on two cancer cell lines. Compound 2d exhibited IC50 values of 0.71 and 17.79 μM comparable to bortezomib against MCF-7 and PC-3, respectively. The results show that the electronic properties and steric hindrance can affect the interaction of these small molecules with their receptor at the active site of the enzyme while the presence of CH2OH group on α-carbon of Michael acceptor is favorable, and para substitution of OMe on phenyl ring of β-carbon can increase the inhibitory potencies. Molecular docking studies confirm our experimental findings about mode of binding of our compounds with 20S proteasome.

Doogh is a dairy drinkable fermented product, whose shelf-life and quality is mostly affected by bacteria such as Staphylococcus spp.. This study investigated the antibacterial activity of essential oils (EOs) from Thymus vulgaris L., Mentha piperita L. and Ziziphora tenuior L., alone or in combination, against Staphylococcus aureus in industrial doogh. A three-level and three-variable face centered central composite design experiment was used. Results showed that EOs significantly inhibited S. aureus growth after 1 and 7 days of storage. According to the model, the maximum inhibition was obtained in the presence of 0.2% of EO, independently of the type, and no synergistic or additive effects were observed. Slightly lower S. aureus survivals were observed at the maximum concentration of Z. tenuior EO. In spite of the antimicrobial activity of these EOs, further research is needed to assess their performance in food matrix and, in particular, in dairy product.

Since the beginning of the epidemic, human immunodeficiency virus (HIV) has infected around 70 million people worldwide, most of whom reside is sub-Saharan Africa. There have been very promising developments in the treatment of HIV with anti-retroviral drug cocktails. However, drug resistance to anti-HIV drugs is emerging, and many people infected with HIV have adverse reactions or do not have ready access to currently available HIV chemotherapies. Thus, there is a need to discover new anti-HIV agents to supplement our current arsenal of anti-HIV drugs and to provide therapeutic options for populations with limited resources or access to currently efficacious chemotherapies. Plant-derived natural products continue to serve as a reservoir for the discovery of new medicines, including anti-HIV agents. This review presents a survey of plants that have shown anti-HIV activity, both in vitro and in vivo.

Previous studies have highlighted the role of immune dysregulation in suicide behavior. Interleukin (IL)-8 is a chemokine with neuroprotective effects whose lower serum concentrations have been detected in individuals committed suicide. In the present study, we genotyped three single nucleotide polymorphisms (SNPs) within IL-8 gene (rs4073, rs2227306 and rs1126647) in 229 individuals who attempted suicide with soft suicide methods, 235 suicide victims and 290 individuals without any history of psychiatric disorders or suicide attempt. The T allele of rs4073 was significantly over-represented in suicide attempt group compared with both control and completed suicide groups (adjusted P values of 8.3E-7 and 9.8E-8 respectively). This SNP was associated with suicide attempt in both dominant and co-dominant models (P values of 6.2E−9 and 4.3 E−8 respectively). The genotype and allele frequencies of other SNPs were not significantly different among the three study groups. The T C A haplotype (rs4073, rs2227306 and rs1126647 respectively) were significantly less prevalent in completed suicide group compared with suicide attempt group (OR (95% CI) = 0.63 (0.46–0.86), adjusted P value = 0.03). Besides, the A T A haplotype has significant lower frequency in individuals who attempted soft suicide compared with controls (OR (95% CI) = 0.44 (0.26–0.75), adjusted P value = 0.02). However, this haplotype was significantly more prevalent in individuals attempted hard methods compared with those attempted soft methods (OR (95% CI) = 2.21 (1.26–3.87), adjusted P value = 0.04). The present study provided further evidence for the role of IL-8 in suicide behavior.

Chemical investigation of the fruit pulp of Murraya koenigii resulted in the identification of two new dimeric carbazole alkaloids, bisgerayafoline D (1) and bismahanimbinol (2) along with four known alkaloids, bispyrayafoline (3), O-methyl mahanine (4), O-methyl mukonal (5), and mahanine (6). Structures of 1-6 were determined with the aid of UV, IR, Mass and extensive NMR spectroscopic studies. Absolute configurations of biaryls in 1 and 2 were assigned using a combination of computational Circular Dichroism (CD) and experimental electronic CD spectroscopic data. Compounds 1-6 were evaluated for anti-oxidant, anti-α-glucosidase, DNA binding, protein interactions and cytotoxic activities. Among all the isolates, mahanine (6) was found to exhibit significant radical scavenging and α-glucosidase inhibitory activities. Compound 6 was also found to be active in cytotoxicity assay against three human cancer cell lines HeLa, HCT116, AGS and this compound was weakly active against normal mouse embryonic fibroblasts (NIH3T3).

Tuberculosis is a highly infectious disease declared a global health emergency by the World Health Organization, with approximately one third of the world's population being latently infected with Mycobacterium tuberculosis. Tuberculosis treatment consists in an intensive phase and a continuation phase. Unfortunately, the appearance of multi drug-resistant tuberculosis, mainly due to low adherence to prescribed therapies or inefficient healthcare structures, requires at least 20 months of treatment with second-line, more toxic and less efficient drugs, i.e., capreomycin, kanamycin, amikacin and fluoroquinolones. Therefore, there exists an urgent need for discovery and development of new drugs to reduce the global burden of this disease, including the multi-drug-resistant tuberculosis. To this end, many plant species, as well as marine organisms and fungi have been and continue to be used in various traditional healing systems around the world to treat tuberculosis, thus representing a nearly unlimited source of active ingredients. Besides their antimycobacterial activity, natural products can be useful in adjuvant therapy to improve the efficacy of conventional antimycobacterial therapies, to decrease their adverse effects and to reverse mycobacterial multi-drug resistance due to the genetic plasticity and environmental adaptability of Mycobacterium. However, even if some natural products have still been investigated in preclinical and clinical studies, the validation of their efficacy and safety as antituberculosis agents is far from being reached, and, therefore, according to an evidence-based approach, more high-level randomized clinical trials are urgently needed.

A series of novel dispiroheterocyclic system containing 4-quinolone nucleus are prepared by 1,3 dipolar cycloaddition of azomethine ylides with a newly prepared (E)-3-arylidene-2,3-dihydro-8-nitro-4-quinolone as dipolarophile. The ylide was generated in situ from isatin and sarcosine/1,3-thiazolane-4-carboxylic acid. The regio and stereochemistry of the synthesized product was established by 1H, 13C, 2D NMR techniques and single crystal X-ray analysis. The molecular mechanism of this cycloaddition has been investigated by means of the density functional theory (DFT) method. The experimental results of regioselectivity product of 1,3 dipolar cycloaddition have shown good agreement with the computed Frontier molecular orbital calculation (FMO) and fukui function analysis.

A simple and short approach for the synthesis of pyrazolo[3,4-b]quinoline (3a–3p) and pyrazolo[4,3-c]quinoline (6a–6 h) using various Lewis acid catalysts was developed. InCl3 was found to be more effective in providing greater yield of products compared to Yb(OTf)3, Sc(OTf)3, SnCl4, AlCl3, TiCl4, ZnCl2, FeCl3, and BF3 · Et2O. Moreover, a comparison of conventional and microwave methods has revealed that the latter method is more efficient compared to former one. Structures were confirmed by Fourier transform infrared, mass spectrometry, 1H and 13C NMR, X-ray crystallography, and elemental analyses. All of the synthesized compounds were evaluated for α-glucosidase inhibitory activity. Compounds 3a, 3p, 3i, 3 h, 3k, 3o, and 3 g exhibited anti α-glucosidase inhibitory activity with IC50 values of 57.5, 60.3, 65.9, 71.9, 80.8, 123.7, and 126.4 µM, respectively, which is quite comparable to the standard drug acarbose (IC50 = 115.8 µM).

A series of 4-quinolone-3-carboxylic acid-containing spirooxindole-pyrrolidine derivatives was synthesized via multicomponent 1,3-dipolar cycloaddition reactions of azomethine ylides with new (E)-4-oxo-6-(3-phenyl-acryloyl)-1,4-dihydroquinoline-3-carboxylic acids in good yields with high regioselectivity. The cycloadducts were characterized by analytical and spectral data including [Formula: see text], [Formula: see text], 2D NMR and mass spectroscopy. The structure of one of the compounds (8a) was investigated theoretically by computational techniques. DFT studies support the proposed mechanism for this cycloaddition reaction. Furthermore, antibacterial activities of the new compounds were evaluated against Gram-positive and Gram-negative bacterial strains. Compounds 8f, 8m and 8p showed potent inhibition activities against selected bacteria. The in vitro cytotoxicity of spirooxindole derivatives (8a-r) was evaluated against MCF-7 breast cancer cell line. Among the various compounds tested, compound 8f [Formula: see text] showed significant cytotoxic activity compared to the standard drug doxorubicin [Formula: see text].

A simple and short approach for the synthesis of pyrazolo[3,4-b]quinoline (3a–3p) and pyrazolo[4,3-c]quinoline (6a–6 h) using various Lewis acid catalysts was developed. InCl3 was found to be more effective in providing greater yield of products compared to Yb(OTf)3, Sc(OTf)3, SnCl4, AlCl3, TiCl4, ZnCl2, FeCl3, and BF3 · Et2O. Moreover, a comparison of conventional and microwave methods has revealed that the latter method is more efficient compared to former one. Structures were confirmed by Fourier transform infrared, mass spectrometry, 1H and 13C NMR, X-ray crystallography, and elemental analyses. All of the synthesized compounds were evaluated for α-glucosidase inhibitory activity. Compounds 3a, 3p, 3i, 3 h, 3k, 3o, and 3 g exhibited anti α-glucosidase inhibitory activity with IC50 values of 57.5, 60.3, 65.9, 71.9, 80.8, 123.7, and 126.4 µM, respectively, which is quite comparable to the standard drug acarbose (IC50 = 115.8 µM).

A simple and short-cut approach for the synthesis of pyrazolo[3,4-b]quinoline (3a-3p) and pyrazolo[4,3-c]quinoline (6a-6 h), using various Lewis acid catalysts was developed. InCl3 was found to be more effective in providing higher yield of products compared to Yb(OTf)3, Sc(OTf)3, SnCl4, AlCl3, TiCl4, ZnCl2, FeCl3 and BF3.Et2O. More over a comparison of conventional and microwave method has revealed that the latter method is more efficient compared to former one. Structures were confirmed by FT-IR, mass spectrometry, 1H, 13C NMR, X-ray crystallography and elemental analyses. All of the synthesized compounds were evaluated for α -glucosidase inhibitory activity and compounds 3a, 3p, 3i, 3 h, 3k, 3o and 3 g exhibited anti α -glucosidase inhibitory activity, IC50 values of 57.5, 60.3, 65.9, 71.9, 80.8, 123.7, 126.4 µM, respectively, which is quite comparable to standard drug, acarbose (IC50 = 115.8 µM).

Enzyme inhibitors play a significant role in the drug discovery process. For instance, acetylcholinesterase (AChE) inhibitors have applications in curing Alzheimer’s disease (AD), senile dementia, ataxia, myasthenia gravis, and Parkinson’s disease. Glutathione S-transferase (GST) inhibitors have applications as adjuvants to overcome anticancer and antiparasitic drug resistance problems. Compounds inhibiting the activity of α-glucosidase are used to treat type 2 diabetes mellitus and obesity problems. This article describes the identification of natural products exhibiting AChE, GST, and α-glucosidase inhibitory activities from medicinally important plants. Additionally, structure–activity relationship (SAR) studies of these newly discovered enzyme inhibitors are also discussed.

Phytochemical studies on the methanolic extract of Drypetes gossweileri afforded N -β- d -glucopyranosyl- p -hydroxyphenylacetamide ( 1 ), p -hydroxyphenylacetic acid ( 2 ), p -hydroxyphenyl-acetonitrile ( 3 ), p -hydroxyacetophenone ( 4 ), 3,4,5-trimethoxyphenol ( 5 ), dolichandroside A ( 6 ), and β-amyrone ( 7 ). Compounds 1 – 7 were identified with the aid of extensive NMR and MS spectroscopic studies. Compound 1 was a new natural product and was isolated for the first time from plant containing N -glucose moiety incorporated in its structure. Compounds 1 – 7 exhibited moderate to the weak source anti-α-glucosidase inhibitory activity. Compound 7 exhibited moderate anti-acetylcholinesterase (AChE) activity while the rest of the isolates were weakly active in this bioassay. Compounds 1 – 7 also showed moderate anti-fungal activity.

Glutathione S-transferase (GST) inhibition-directed fractionations on the ethanolic extract of Artocarpus nobilis of Sri Lankan origin yielded four known triterpenoids, cyclolaudenyl acetate (1), lupeol acetate (2), β-amyrine acetate (3), and zizphursolic acid (4), along with five known flavonoids, artonins E (5), artobiloxanthone (6) artoindonesianin U (7), cyclocommunol (8) and multiflorins A (9). Our recent chemical studies on the methanolic extract of Matricaria chamomilla, collected from Manitoba, afforded one new compound, matriisobenzofuran (10), and six known natural products, fraxidin (11), scopoletin (12), apigenin (13), apigenin 7-O-β-glucopyranoside (14), palmatoside A (15) and p-hydroxyacetophenone (16). Compounds 1–16 were identified with the aid of extensive NMR and MS spectral data. Compounds 1–16 exhibited a wide range of GST inhibition activity. Compounds 5–9 exhibited significant anti-oxidant activity in DPPH free radical scavenging assay. Compounds 10 and 11 were also moderately active in anti-leishmanial assay.

From the aerial parts of Buxus hyrcana, three triterpenoidal alkaloids, 17-oxo-3-benzoylbuxadine (1), buxhyrcamine (2), and 31-demethylcyclobuxoviridine (3), along with 16 known compounds, cyclobuxo-viridine (4), N-b-dimethylcyclobuxoviricine (5), E-buxenone (6), Z-buxenone (7), moenjodaramine (8), homomoenjodarmine (9), buxamine A (10), buxamine B (11), 31-hydroxybuxamine B (12), N-20-formylbuxaminol E (13), papillozine C (14), buxmicrophylline F (15), buxrugulosamine (16), cyclobuxophylline 0 (17), spirofornabuxine (18) and arbora-1,9(11)-dien-3-one (19) were isolated. Their structures were elucidated by using NMR spectroscopic methods. All of the compounds exhibited moderate to weak acetylcholinesterase, butyrylcholinesterase and glutathione S-transferase inhibitory activities. Compounds 1-19 also exhibited modest anti-fungal activities against Candida albicans. Compounds 1, 2, 8, 9 and 18 also exhibited weak anti-leishmanial activity. (C) 2010 Elsevier Ltd. All rights reserved.

Phytochemical studies on the ethanolic extracts of Caesalpinia bonduc (Fabaceae) yielded two new homoisoflavonoids, caesalpinianone, and 6- O -methylcaesalpinianone along with five known natural products, namely, hematoxylol, stereochenol A, 6′- O -acetylloganic acid, 4′- O -acetylloganic acid, and 2- O -β- d -glucosyloxy-4-methoxybenzenepropanoic acid. Structures of these compounds were elucidated with the aid of extensive NMR spectral studies. All of these compounds exhibited different levels of glutathione S -transferase (GST) inhibitory and antifungal activities.

From the aerial parts of Barleria prionitis , one new phenylethanoid glycoside, barlerinoside ( 1 ) along with six known iridoid glycosides, shanzhiside methyl ester ( 2 ), 6- O - trans - p -coumaroyl-8- O -acetylshanzhiside methyl ester ( 3 ), barlerin ( 4 ), acetylbarlerin ( 5 ), 7-methoxydiderroside ( 6 ), and lupulinoside ( 7 ) were isolated. Structures of these compounds were elucidated with the aid of extensive NMR spectral studies and chemical reactions. Compound 1 was significantly active in glutathione S -transferase (GST) inhibition assay with an IC 50 value of 12.4 μM but weakly active in acetylcholinesterase (AChE) inhibition assay. Compounds 2 – 7 also exhibited different levels of GST, AChE inhibitory and free radical scavenging activities.

Several derivatives of coumarin-3N-carboxamides (3-21) have been prepared via the reaction of the coumarin-3-carbonyl chloride (1) with a number of nucleophiles. Novel double-headed coumarin-3N-carboxamides (26-33) were also produced using the same method. The Pechmann-Duisberg reaction was applied to prepare new benzo[f]- benzo[h]coumarins and 4-(chloromethyl)-pyrano[3,2-c]coumarin-2-one (36-42). The reaction of 1-chloromethylbenzo[f]coumarins (36) with cyanide anion under different reaction conditions was also investigated in order to assess its suitability for nucleophilic substitution reactions as well as ring transformation products (43-49). Synthesis of 1-((benzo[d]thiazol-2-yl)methyl)-9-hydroxybenzo[f]coumarin (50) represented the first example of methylene bridge-head heterocyclecontaining benzo[f]coumarin. Some of the newly prepared coumarins exhibited anti-bacterial activity against Gram Positive and Gram negative bacteria. Compound 36d was found to be active against all the screened bacteria. Photophysical studies were performed on selected fluorescent benzo[f]- and benzo[h]coumarin and the quantum yields were also calculated. All new compounds were characterized by IR, MS, 1H and 13C NMR, as well as elemental analysis.

Phytochemical studies on the methanolic extract of Amrosia psilostachya, native to Manitoba, have resulted in the isolation of two new sterols, ambrosinal A (1) and ambrosinal B (2) along with a known sesquiterpene lactone, coronopilin (3). Spectroscopic methods were used to establish the structures of these new and known compounds. Single crystal X-ray diffraction studies on compound 3 were also performed. Compounds 1-2 exhibited moderate antibacterial activity against pathogenic bacteria while compound 3 was weakly active in glutathione Stransferase inhibition assay.