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Glomerella fusarioides-mediated structural modifications of steroidal anabolic drug, oxandrolone (1), yielded a new product 17β,11α-dihydroxy-17α-methylandrosta-2-oxa-4-ene-3-one (2). Similarly, Cunninghamella elegans-catalyzed transformation of a steroidal anti-epileptic drug ganaxolone (3) afforded a new metabolite 14α-hydroxy-5α-pregnan-1-ene-3,20-dione (4). Structures of new metabolites 2 and 4 were deduced via 1D-, and 2D-NMR, HREI-, HRFAB-MS, and IR spectroscopic techniques. New derivative 2 showed a remarkable anti-aromatase activity with an IC50 = 0.6 ± 0.005 μM, when compared to substrate 1 (IC50 = 0.808 ± 0.07 μM), and standard anti-cancer drug exemestane (IC50 = 0.232 ± 0.031 μM). Ganaxolone (3) (IC50 = 13.76 ± 2.00 μM) also showed a good activity against human aromatase enzyme, while its derivative 4 was found to be inactive. Inhibition of aromatase enzyme is a key approach in the treatment of estrogen positive breast cancers. Compounds 1-4 were non-cytotoxic to 3T3 cell line (mouse fibroblast).

The present study reports the biotransformation of an anabolic-androgenic steroid (AAS) drostanolone heptanoate (1) by using two microbial cultures, Beauveria bassiana, and Macrophomina phaseolina. Fermentation of 1 with B. bassiana yielded five new transformed products 2–6, while with M. phaseolina it afforded two new 7–8, and two known 9–10 metabolites. The main sites of hydroxylation in the steroidal skeleton of 1 were at C-5, C-7, C-11, C-14, C-15, and C-20, hydrolysis of the ester moiety at C-17, and reduction of the carbonyl group at C-3. The structures of the transformed products were determined by using mass, NMR, and other spectroscopic techniques.

A new pentacyclic triterpene 3-O-β-(E)-(4-O-acetylferuloyl)-lupeol (1) possessing an unusual (E)-acetylferuloyl moiety at C-3 and a new bicoumarin 7,7′-dimethoxy-6,6′-dicoumarinyl ether (2) were isolated from the liana Landolphia lucida K. Schum, along with fourteen previously known compounds 3-16, where methandriol dipropionate (3) and 2,3-bis-(4-hydroxy-3-methoxy-benzyl)-dimethyl- succinate (5) were obtained for the first time from natural sources. The structures of the new compounds were established on the basis of extensive 1D and 2D NMR spectroscopy, and HRMS data analyses. The absolute configuration of 1 was determined by circular dichroism (CD) spectroscopy. Furthermore, compounds 1 and 2 had exhibited a significant antibacterial activity against Escherichia coli (ATCC 25922) with MIC values of 2.3 μM and 4.6 μM, respectively; while compounds 4 and 5 showed antiglycation and α-glucosidase inhibitory activities.

Synapsin I (SynI) is the most abundant brain phosphoprotein present at presynaptic terminals that regulates neurotransmitter release, clustering of synaptic vesicles (SVs) at active zones, and stimulates synaptogenesis and neurite outgrowth. Earlier studies have established that SynI displays pH-dependent tethering of SVs to actin filaments and exhibits a maximum binding around neutral pH, however, the effect of pH shift from acidic to basic on the conformational stability of SynI has not been explored yet. Another important aspect of SynIa is its O-GlcNAcylation (O-GlcNac) at the Thr87 position, which is responsible for the positive regulation of synaptic plasticity linked to learning and memory in mice. Furthermore, reduced levels of O-GlcNAc have been observed in Alzheimer's disease, suggesting a possible link to deficits in synaptic plasticity. In this study, the effect of pH and glycosylation on the structure and functional stability of SynIa is determined through molecular dynamics (MD) simulation approach. The 3D structure of SynIa was established via threading-based homology modeling methods. It was observed that the structure of SynIa adopts extended conformational changes as the pH shifts from acidic to basic, resulting in a compact conformation at pH 8.0. Moreover, the results obtained by comparing the glycosylated and unglycosylated protein indicated that the glycan moiety imparts stability to the protein by forming intramolecular hydrogen bond interactions with the protein residues. The results indicate that although O-GlcNAc moieties do not induce a significant change in SynIa structure they minimize protein dynamics, likely leading to enhanced protein stability.

Kadsura heteroclita Roxb. Craib. (Schisandraceae), is a vine plant mainly distributed in southwest part of China. A new dibenzocyclooctadiene lignan, kadsulignan W (1), along with eleven known lignans (2-12) were isolated from chloroform soluble fraction of stems of Kadsura heteroclita. The structure of new lignan was elucidated by extensive spectroscopic techniques, namely one- and two-dimensional NMR spectroscopy, and HRESI-MS analysis. The absolute configuration of the biphenyl ring in the new dibenzocyclooctadiene lignan was discerned by circular dichroism (CD) spectroscopy. Antioxidative effects of these compounds were evaluated on human isolated neutrophils, and compounds 5, 8, 9, and 10 were found to be strongly active with the IC50 of 36.68, 34.41, 35.97, and 33.65 µM, respectively. Furthermore, compound 8 was also found to be cytotoxic against human gastric cancer cells (BGC 823), and human cervical cancer cell lines (HeLa) with the IC50 values of 11.0, and 23.8 µM, respectively.

Candida albicans is the causative agent of candidiasis in immunocompromised and diseased individuals. The current study was designed to evaluate the antifungal activity of Trachyspermum ammi (L.) Sprague seeds ethanolic extract and hexanes fraction against Candida albicans, both in-vitro and in-vivo. The minimal inhibitory concentration of hexanes fraction was found to be 225 μg/mL, as compared to the standard drug amphotericin B (200 μg/mL). For the treatment of cutaneous candidiasis in BALB/c mice model, the extract and fraction containing ointment was topically applied on flank of mice at various concentrations, and 90–100% recovery in mice was observed which was better than the standard drug, clotrimazole. The GC/MS analysis of hexanes extract indicated the presence of three major components, including (43.91%), O-cymene (25.53%), and γ-terpinene (22.64%). The results showed that T. ammi possess potential antifungal effect, and can be used for the development of novel antifungal agents after further pre-clinical and clinical trials.

Graphical abstract, Seven new derivatives, 6α-hydroxy-1-methyl-3-oxo-5α-androst-1-en-17-yl acetate (2), 6α,17β-dihydroxy-1-methyl-3-oxo-5α-androst-1-en (3), 7β-hydroxy-1-methyl-3-oxo-5α-androst-1-en-17-yl acetate (4), 15β,20-dihydroxy-1-methyl-3-oxo-5α-androst-1-en-17-yl acetate (5), 15β-hydroxy-1-methyl-3-oxo-5α-androst-1-en-17-yl acetate (6), 12β,17β-dihydroxy-1-methyl-3-oxoandrosta-1,4-dien (11), and 7β,15β,17β-trihydroxy-1-methyl-3-oxo-5α-androst-1-en (14), along with six known metabolites, 17β-hydroxy-1-methyl-3-oxoandrosta-1,4-dien (7), 17β-hydroxy-1-methyl-3-oxo-5α-androst-1-en (8), 17β-hydroxy-1-methyl-3-oxo-5β-androst-1-en (9), 1-methyl-5β-androst-1-en-3,17-dione (10), 1-methyl-3-oxoandrosta-1,4-dien-3,17-dione (12), and 17β-hydroxy-1α-methyl-5α-androstan-3-one (13) of metenolone acetate (1), were synthesized through whole-cell biocatalysis with Rhizopus stolonifer, Aspergillus alliaceous, Fusarium lini, and Cunninghamella elegans. Atamestane (12), an aromatase inhibitor, was synthesized for the first time via F. lini-mediated transformation of 1 as the major product. Hydroxylation, dehydrogenation, and reduction were occurred during biocatalysis. Study indicated that F. lini was able to catalyze dehydrogenation reactions selectively. Structures of compounds 1–14 were determined through NMR, HRFAB-MS, and IR spectroscopic data. Compounds 1–14 were identified as non-cytotoxic against BJ human fibroblast cell line (ATCC CRL-2522). Metabolite 5 (81.0 ± 2.5%) showed a potent activity against TNF-α production, as compared to the substrate 1 (62.5 ± 4.4%). Metabolites 2 (73.4 ± 0.6%), 8 (69.7 ± 1.4%), 10 (73.2 ± 0.3%), 11 (60.1 ± 3.3%), and 12 (71.0 ± 7.2%), also showed a good inhibition of TNF-α production. Compounds 3 (IC50 = 4.4 ± 0.01 µg/mL), and 5 (IC50 = 10.2 ± 0.01 µg/mL) showed a significant activity against T-cell proliferation. Identification of selective inhibitors of TNF-α production, and T-cell proliferation is a step forward towards the development of anti-inflammatory drugs.

Breast cancer is one the most aggressive cancer worldwide, especially Pakistan due to limited therapeutic options. This study was conducted to repurpose the use of selective serotonin reuptake inhibitors (SSRIs), in the treatment of breast cancers, and merit to pursue drug re-positioning in oncology. Anti-proliferative activity of SSRIs, such as fluoxetine, paroxetine, and sertraline hydrochloride on the growth of AU-565, MCF-7, MDA-MB-231, and BT-474 breast cancer cell lines, along with human fibroblast BJ cells was determined in vitro. Changes in nuclear morphology (DAPI staining), and induction of apoptosis (flow cytometry, and caspase-3 activation) were also studied. Sertraline hydrochloride most effectively inhibited the growth of breast cancer cells in vitro. Therefore, pharmacological mechanism involved in sertraline mediated cell death was investigated in HER2+ AU565 cell line. Enhanced nuclear fragmentation, increased Annexin (+) cells, and caspase-3/7 activation indicated that sertraline-mediated cell death could be a result of BCl2-independent apoptosis as evidenced by expression of Bax, and BCl2 genes. Taken together, our results identified sertraline hydrochloride, as a potential candidate for the treatment of HER2-positive breast cancer. Even though these are in vitro results, this study opens great opportunity in the field of drug repurposing for the development of chemotherapeutic agents.

The microbial transformation of anabolic androgenic steroid mestanolone (1) with Macrophomina phaseolina and Cunninghamella blakesleeana has afforded seven metabolites. The structures of these metabolites were characterized as 17β-hydroxy-17α-methyl-5α-androsta-1-ene-3,11-dione (2), 14α,17β-dihydroxy-17α-methyl-5α-androstan-3,11-dione (3), 17β-hydroxy-17α-methyl-5α-androstan-1,14-diene-3,11-dione (4), 17β-hydroxy-17α-methyl-5α-androstan-3,11-dione (5), 11β,17β-dihydroxy-17α-methyl-5α-androstan-1-ene-3-one (6), 9α,11β,17β-trihydroxy-17α-methyl-5α-androstan-3-one (7), and 1β,11α,17β-trihydroxy-17α-methyl-5α-androstan-3-one (8). All the metabolites, except 5 and 6, were identified as new compounds. Substrate 1 (IC50 = 27.6 ± 1.1 μM), and its metabolites 2 (IC50 = 19.2 ± 2.9 μM) and 6 (IC50 = 12.8 ± 0.6 μM) exhibited moderate cytotoxicity against the HeLa cancer cell line (human cervical carcinoma). All metabolites were noncytotoxic to 3T3 (mouse fibroblast) and H460 (human lung carcinoma) cell lines. The metabolites were also evaluated for immunomodulatory activity, and all were found to be inactive.

Synthesis of pyrazole-3-carboxylic acid was progressed via two different protocols, one of which is solid state. Pyrazole-3-carboxylic acid was converted into different derivatives such as ester, urea, amide and nitrile. The amide compound was converted to nitrile using SOCl2 and DMF. Solid state heating of carboxylic acid gave decarboxylated product. Cyclization of tetra-substituted pyrazole with hydrazines resulted in pyrazolopyridazinones. The antimicrobial activities of the synthesized pyrazole derivatives against Bacillus cereus, Escherichia coli, Micrococcus luteus, Staphylococcus aureus, and Saccharomyces cerevisiae were evaluated. One of the pyrazole derivatives which possess nitro group showed antimicrobial activity in only B. cereus, a Gram-positive bacteria, with an MIC of 128 μg/mL.

A series of benzamide derivatives 1–12 with various functional groups (–H, –Br, –F, –OCH3, –OC2H5, and –NO2) was synthesized using an economic, and facile Microwave-Assisted Organic Synthesis, and evaluated for acetylcholinesterase (ACHE) and butyrylcholinesterase (BCHE) activity in vitro. Structure–activity relationship showed that the substitution of –Br group influenced the inhibitory activity against BCHE enzyme. Synthesized compounds were found to be selective inhibitors of BCHE. In addition, all compounds 1–12 were found to be non-cytotoxic, as compared to the standard cycloheximide (IC50 = 0.8 ± 0.2 µM). Among them, compound 3 revealed the most potent BCHE inhibitory activity (IC50 = 0.8 ± 0.6 µM) when compared with the standard galantamine hydrobromide (IC50 = 40.83 ± 0.37 µM). Enzyme kinetic studies indicated that compounds 1, 3–4, and 7–8 showed a mixed mode of inhibition against BCHE, while compounds 2, 5–6 and 9 exhibited an uncompetitive pattern of inhibition. Molecular docking studies further highlighted the interaction of these inhibitors with catalytically important amino acid residues, such as Glu197, Hip438, Phe329, and many others.

Picrotoxinin (1), a stable natural neurotoxin containing a highly oxygenated polycyclic rigid compound, was first isolated from berries of Anamirta cocculus (L.) Wight & Arn. (formerly known as Menispermum cocculus). The present work was aimed to study the modification of the complex polycyclic structure of picrotoxinin (1) by using microbial transformation. Initially various fungi, such as Macrophomina phaseolina, Cunninghamella blakesleeana, Aspergillus flavus, Aspergillus niger, Cephalosporium aphidicola, and Fusarium lini were screened for their ability to modify the structure of 1. Only one fungus Macrophomina phaseolina was able to catalyze the structural modification of picrotoxinin (1). The subsequent whole cell catalysis produced an intramolecular trans-esterified product 2. The structure of the transformed product was deduced by spectroscopic, and single-crystal X-ray diffraction analyses. A comparative study on convulsant activity of picrotoxinin (1) and its metabolite 2 was conducted in mice. Interestingly, metabolite 2 showed a delayed convulsant activity, as compared to the compound 1.

Glomerella fusaroide, and Rhizopus stolonifer were effectively able to transform the steroidal hormone melengestrol acetate (MGA) (1) into four (4) new metabolites, 17α-acetoxy-11α-hydroxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione (2), 17α-acetoxy-11α-hydroxy-6-methyl-16-methylenepregna-1,4,6-triene-3,20-dione (3), 17α-acetoxy-6,7α-epoxy-6β-methyl-16-methylenepregna-4,6-diene-3,20-dione (4), and 17α-acetoxy-11β,15β-dihydroxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione (5). All these compounds were structurally characterized by different spectroscopic techniques. The objective of the current study was to assess the anti-inflammatory potential of melengestrol acetate (1), and its metabolites 2–5. The metabolites and the substrate were assessed for their inhibitory effects on proliferation of T-cells in vitro. The substrate (IC50 = 2.77 ± 0.08 µM) and its metabolites 2 (IC50 = 2.78 ± 0.07 µM), 4 (IC50 = 2.74 ± 0.1 µM), and 5 (IC50 =

A new steroidal alkaloid, michainine (1), was isolated from Fritillaria michailovskyi Fomin, along with nine known compounds 2–10 of different classes, including ribonucleoside, steroids, and fatty acids, which were isolated for the first time from this plant. Their structures were elucidated through extensive spectroscopic techniques, as well as by comparing the data in the literature. Furthermore, the dichloromethane fraction of F. michailovskyi showed a positive butyrylcholinesterase inhibitory activity, along with non-cytotoxicity against 3T3 cell line.

BACKGROUND Obesity is one of the major health problems with inherent risk of type 2 diabetes, hypertension, CVDs, etc. Adipogenesis is a major contributor in the process of obesity. Inhibition of adipocytes differentiation is one of the key approaches to treat obesity. OBJECTIVE To discover the new inhibitors of adipogenesis as the treatment for obesity. METHOD We describe here, the synthesis, and anti-adipogenic activity of thiourea derivatives 1-14. These derivatives were synthesized by the reactions of phenyl and pentafluorophenyl isothiocyanate with different aromatic amines. Pure compounds 1-14 were evaluated for their in vitro antiadipogenesis activity employing 3T3-L1 cells lines. RESULTS Compounds 1-3, 5-9, and 11-14 significantly inhibited the pre-adipocyte differentiation into adipocytes, which was measured by staining the cells, and through morphological examination. Compound 10 (1-(4"-Chlorophenyl)-3-(pentafluorophenyl)-thiourea) showed a potent inhibition of adipocyte differentiation with IC50 = 740.00 ± 2.36 nM, which was more potent than the standards, epigallocatechin gallate (IC50 = 16.73 ± 1.34 μM), and curcumin (IC50 = 18.62 ± 0.74 μM). All other compounds showed a moderate to weak anti-adipogenesis activity. Compounds 1- 14 were also evaluated for their cytotoxicity. Compounds 3, 10, and 14 showed some toxicity to the cancer cell lines, while compounds 2, 3, 10, 12, and 14 showed a moderate to weak cytotoxicity against the normal cell lines. CONCLUSION All the compounds reported in this paper are known, except compound 11. They have been identified as new inhibitors of Adipogenesis. Adipogenesis is the process of adipocytes differentiation from pre-adipocytes. This extensively studied model of cell diff differentiation. Further synthetic modifications, and optimization of anti-adipogenic activity may lead to the development of anti-obesity agents.

A series of benzoxazinones 1 – 28 were synthesized via reaction of anthranilic acid with various substituted benzoyl chlorides in the presence of triethylamine in chloroform. Compounds 1 – 18 showed a good inhibition of α -chymotrypsin with IC 50 ± SEM values between 6.5 and 341.1 μM. Preliminary structure-activity relationships studies indicated that the presence of substituents on benzene ring reduces the inhibitory potential of benzoxazinone. Also the increased inhibitory potential due to fluoro group at phenyl substituent was observed followed by chloro and bromo substituents. Compounds with strong electron donating or withdrawing groups on phenyl substituent, showed a good inhibitory potential at ortho > meta > para position. Kinetics studies showed diverse types of inhibition, except uncompetitive-type inhibition. The Ki values ranged between 4.7 and 341.2 μM. Interestingly, most of these compounds were non-cytotoxic to 3T3 cell line at 30 μM, except compounds 6 , 14 and 15 . Competitive inhibitors of chymotrypsin are like to inhibit other α -chymotrypsin-like serine proteases due to structural and functional similarities between them. The inhibitors identified during the current study deserve to be further studied for their therapeutic potential against abnormalities mediated by chymotrypsin or other serine protease.

Three new metabolites were obtained on incubation of androgenic steroid mesterolone ( 1 ) with Cunninghamella blakesleeana . These metabolites were identified as 1α-methyl-11 β ,14α,17β-trihydroxy-5α-androstan-3-one ( 2 ), 1α-methyl-7 β ,17 β -dihydroxy-5α-androstan-3-one ( 3 ), and 1α-methyl,17 β -hydroxy-5α-androstan-3,7-dione ( 4 ). During this study, hydroxylation at C-11, C-14, and C-15, and oxidation at C-7 of substrate 1 were observed. β -Hydroxylation at C-11 is a rather unique transformation by C. blakesleeana , as α-hydroxylation is reported to be catalyzed by most of the other microorganisms.

The current study was aimed to evaluate the prolyl endopeptidase (PEP) inhibitory activity of glutinol (1), azadiradione (2), quercetin 3-O-β- d -glactopyranoside (3), catechin (4), quercetin (5), naringenin (6) isolated from Parrotia persica C. A. Mey. Naringenin (6) was further derivatized into 7-O-propargylnaringenin (7), 4′,6′,4″-O-propargylchalcone (8), and 4′,4″-O-propargylchalcone (9). All compounds 1–9 were evaluated for their PEP inhibition activity. PEP is associated with several diseases, including dementia, and Alzheimer’s disease (AD). Azadiradione (2) was less active with IC50 = 356.80 ± 2.9 µM, whereas quercetin (5) showed a potent activity with IC50 = 37.12 ± 2.2 µM, as compared to IC50 = 125.00 ± 1.5 µM of standard drug bacitracin. Naringenin (6) was found to be inactive, whereas its new analogues 7–9 were identified as potent inhibitors of PEP with IC50 = 35.20, 41.20, and 29.60 µM, respectively. Kinetic studies of active compounds indicated their modes of inhibition. Compounds 7–9 were found to be mixed-type inhibitors, while compound 5 was found to be non-competitive inhibitor.

A library of benzimidazole derivatives 1-20 were synthesized, and studied for their α-chymotrypsin (α-CT) inhibitory activity in vitro. Kinetics and molecular docking studies were performed to identify the type of inhibition. Compound 1 was found to be a good inhibitor of α-chymotrypsin enzyme (IC50=14.8±0.1μM, Ki=16.4μM), when compared with standard chymostatin (IC50=5.7±0.13μM). Compounds 2-8, 15, 17, and 18 showed significant inhibitory activities. All the inhibitors were found to be competitive inhibitors, except compound 17, which was a mixed type inhibitor. The substituents (R) in para and ortho positions of phenyl ring B, apparently played a key role in the inhibitory potential of the series. Compounds 1-20 were also studied for their cytotoxicity profile by using 3T3 mouse fibroblast cells and compounds 3, 5, 6, 8, 12-14, 16, 17, 19, and 20 were found to be cytotoxic. Molecular docking was performed on the most active members of the series in comparison to the standard compound, chymostatin, to identify the most likely binding modes. The compounds reported here can serve as templates for further studies for new inhibitors of α-chymotrypsin and other chymotrypsin-like serine proteases enzymes.

Biotransformation of a synthetic progestonic hormone dydrogesterone (1), C21H28O2, with a plant pathogenic fungus Macrophomina phaseolina yielded two new 2 and 3, and a known 4 metabolites. These analogues were identified as, 3β,11α-dihydroxy-5β,9β,10α-pregna-7-ene-6,20-dione (2), 15β-hydroxy-9β,10α-pregna-4,6-diene-3,20-dione (3), and 8α-hydroxy-9β,10α-pregna-4,6-diene-3,20-dione (4). Major structural changes were observed in metabolite 2. New metabolite 3 showed anti-inflammatory potential, and was found to be the potent inhibitor of intracellular reactive oxygen species (ROS) from whole blood phagocytes (IC50 = 4.2 ± 0.3 μg/mL), as compared to standard drug Ibuprofen (IC50 = 11.2 ± 1.9 μg/mL). The metabolites 2, 3, and 4 were found to be non-toxic to NIH-3T3 (CRL-1658) normal cell line. This indicated anti-inflammatory potential of resulting metabolites.

Background Multidrug resistance (MDR) is a major challenge in the treatment of infectious diseases. The MDR in urinary tract infection causing bacteria, such as Escherichia coli, has made treatment of UTI very difficult. Objective The aims of the current study were to synthesize a library of harmaline derivatives, and to evaluate their activity against various strains of multi-drug resistance (MDR) E. coli. Method Harmaline derivatives were synthesized by the reaction of harmaline (1) with various acid halides and anhydrides. These compounds were subjected to susceptibility determination by in vitro MTT assay. The changes in morphology of the bacterial cells after the treatment with harmaline (1) and its new derivatives 2 and 3 were studied through scanning electron, atomic force and fluorescence microscopy. Effect of harmaline and its derivatives in the production of Reactive Oxygen Species (ROS) in MDR E. coli was assessed through lucigenin chemiluminescence assay. Results The selected compounds assisted the fluorescently labeled dye DiBAC4 (3) to bind to the lipid rich intra-cellular entities, and thus produced a sharp green fluorescence by easily penetrating into the compound-induced depolarized membrane of MDR E. coli. These compounds have also triggered significant generation of ROS from bacterial cells as compared to the conventional antibiotics. The current study demonstrated that harmaline (1), and its derivatives 2 and 3 were identified as anti-MDR agents against MDR strains of E. coli. Antibacterial effect of compounds 1-3 on MDR E. coli is possibly due to membrane depolarization due to ROS-induced damage to the bacterial cell membrane. Conclusion Harmaline and its derivatives were identified as anti-MDR agents against various highly resistant and Pakistani MDR clinical isolates of E. coli. These discovered compounds may serve as the leads for further studies towards the development of treatment against the infection caused by MDR E. coli.

Background Anthranilic acid derivatives are important pharmacophores in drug discovery. Several of them are currently being used, such as mefenamic acid and meclofenamates, possess analgesic, anti-inflammatory and antipyretic activities. Some anthranilic acid-based scaffolds have also been reported for the management of metabolic disorders. Objectives The aim of the current study was to investigate the antiglycation potential of 2-anilino benzoic acid derivatives against (N-phenylanthranilic acid) fructose- human serum albumin (HSA) glycation. The study also analyzed the effects of newly identified antiglycation inhibitors on AGEs-mediated intracellular reactive oxygen species production, and associated impaired proliferation of the hepatocytes. Methods The present study focuses on the antiglycation activity of 2- anilinobenzoic acid derivatives 1-18 in in-vitro human serum albumin (HSA)- fructose model. These derivatives were also identified as non-toxic to 3T3 mouse fibroblast cell-line using metabolic assay. The effect of the most promising derivative 1, 2- (2, 4- dinitroanilino)benzoic acid, was studied in a dose dependent manner, co-incubated with fructose-derived AGEs (0- 200 μg/mL), on rat hepatocytes proliferation and associated intracellular generation of ROS via MTT assay and DCFH-DA technique, respectively. Results We found that derivative 1 ameliorates the elevated intracellular oxidative stress and associated diminished proliferation of the hepatocytes in response to AGEs. Conclusion In conclusion, we identify novel 2- anilino benzoic acid derivatives as antiglycation agents through in-vitro and cellular-based models.

A protocol that carboxylic acids esterifies with the quaternary ammonium salt of deep eutectic solvent (DES) is presented, which opens a new access to ester using DES as alkylating agent, solvent, and catalyst. The reaction runs smoothly in DES without any other additives. Substituted cinnamic acids, aromatic acids, and aliphatic acids can be esterified in moderate to good yields. The advantages of this reaction include excellent functional group compatibility and simple reaction procedure.

Aims The emergence of multidrug-resistant (MDR) Staphylococcus aureus is a challenge for the treatment of infections. We report here the antimicrobial activity of artonin I against MDR Staph. aureus, its mechanism of reversal of resistance and synergistic effects by combinational therapy. Methods and Results Artonin I, a flavonoid obtained from Morus mesozygia Stapf., inhibited the bacterial efflux pump and induced depolarization of the cell membrane. To study the dose-dependent production of reactive oxygen species in MDR cells by artonin I, lucigenin chemiluminescence assay was employed. Reversal of multidrug resistance by artonin I, in combination with antibiotics, was measured by a fractional inhibitory concentration index assay. The effect of artonin I on ultrastructural features was studied by microscopy. Artonin I increased the penetration of ethidium bromide by blocking the efflux mechanism. It also helped anionic probe DiBAC4 (3) to bind with the lipid-rich cellular components by causing depolarization of the cell membrane. Artonin I reversed multidrug resistance and increased the susceptibility of existing antibiotics by lowering their minimum inhibitory concentrations (MICs). Conclusions Artonin I was identified both as a new antibacterial agent and a helper molecule to potentiate the action of otherwise inactive antibiotics. Significance and Impact of the Study Artonin I can be developed as potential antimicrobial and resistance reversal agent.

Biotransformation of the anabolic steroid dianabol (1) by suspended-cell cultures of the filamentous fungi Cunninghamella elegans and Macrophomina phaseolina was studied. Incubation of 1 with C. elegans yielded five hydroxylated metabolites 2–6, while M. phaseolina transformed compound 1 into polar metabolites 7–11. These metabolites were identified as 6β,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (2), 15α,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (3), 11α,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (4), 6β,12β,17β-trihydroxy-17α-methylandrost-1,4-dien-3-one (5), 6β,15α,17β-trihydroxy-17α-methylandrost-1,4-dien-3-one (6), 17β-hydroxy-17α-methylandrost-1,4-dien-3,6-dione (7), 7β,17β,-dihydroxy-17α-methylandrost-1,4-dien-3-one (8), 15β,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (9), 17β-hydroxy-17α-methylandrost-1,4-dien-3,11-dione (10), and 11β,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (11). Metabolite 3 was also transformed chemically into diketone 12 and oximes 13, and 14. Compounds 6 and 12–14 were identified as new derivatives of dianabol (1). The structures of all transformed products were deduced on the basis of spectral analyses. Compounds 1–14 were evaluated for β-glucuronidase enzyme inhibitory activity. Compounds 7, 13, and 14 showed a strong inhibition of β-glucuronidase enzyme, with IC50 values between 49.0 and 84.9 μM.

Background Benzimidazoles are important pharmacophores in drug discovery, and currently its derivatives such as flubendazole, omeprazole, and astemizole are used for the treatment of anthelmintic, ulcerative, and histaminic diseases, respectively. Objectives The aim of the current study was to investigate the antiglycation activity of nitrobenzimidazole derivatives against fructose-mediated human serum albumin (HSA) glycation. The study was also aimed at investigating the effects of newly identified antiglycation inhibitors on AGEsinduced intracellular reactive oxygen species (ROS) production, and associated impaired proliferation of the hepatocytes. Methods The present study focuses on the antiglycation activity of 6-nitrobenzimidazole derivatives 1-13 in in-vitro human serum albumin (HSA)- fructose model. These derivatives were also identified as non-toxic against 3T3 mouse fibroblast cell-line in MTT-based assay. The effect of the most promising derivative 5, 4-(6-nitro-1H-benzimidazol-2-yl)-1,2,3-benzenetriol, was studied in a dose dependent manner, co-incubated with fructose-derived AGEs (0- 200 μg/mL) on rat hepatocytes proliferation and associated intracellular generation of ROS via MTT-based assay and DCFHDA technique, respectively. Results We found that derivative 5 ameliorates the elevated intracellular oxidative stress and associated diminished proliferation of the hepatocytes in response to AGEs. Conclusion In conclusion, we identified novel 6-nitrobenzimidazole derivatives as antiglycation agents through in-vitro, and cell-based models.

Sulfamethazine (SMZ) (1) is an antibacterial sulfa drug which suppresses the synthesis of dihydrofolic acid. It is used for the treatment of infections in livestock; such as gastrointestinal, and respiratory tract infections. During the current study, synthesis, characterization, and evaluation of immunomodulatory activities of derivatives of sulfamethazine (SMZ) (3-39) was carried out. These derivatives were synthesized by the reaction of sulfamethazine with a range of acid chlorides. All the compounds were characterized by using modern spectroscopic techniques, such as 1H-, and 13C-NMR, EI-MS, and HRFAB-MS. Compounds 3-10, 14, and 15 were identified as new compounds. Immunomodulatory effect of compounds 3-39 on different parameters of innate immune response was evaluated, including the production of Reactive Oxygen Species (ROS) from human whole blood and isolated polymorphonuclear neutrophils (PMNs), nitric oxide (NO), and pro-inflammatory cytokine TNF-α. All the new compounds, except 14 and 15, showed a significant anti-inflammatory activity. Compounds 3-39 were also evaluated for their anti-bacterial activity and cytotoxicity (3T3 mouse fibroblast cell lines). All the compounds were found to be non-cytotoxic against normal cell lines.

Natural products, longissiminone A (1) and longissiminone B (2), were isolated along with a known compound, glutinol (3), from a medicinal lichen, Usnea longissima. The structures of compounds 1 and 2 were determined with the help of spectroscopic studies. Compound 1 was found to possess potent anti-inflammatory activity in a cell-based contemporary assay. Cytotoxicity activity measured by cell viability assay showed 100% viability in the presence of 200 microg/mL conc. of these compounds.

Phytochemical investigations on the organic extracts of the leaves of Suregada multiflora have led to the isolation of ten tetracyclic diterpene lactones 1–10 , members of a rare class of abiatene diterpene lactones. Compounds 1–5 were found to be new. The structures of gelomulides F ( 11 ), D ( 12 ) and E ( 13 ) were revised on the basis of 2D NMR and X-ray diffraction evidences. Compounds 1 and 2 contain an epoxy linkage between C-8 and C-14, whereas compounds 3–5 were identified as 8,14-dihydroxy analogues of diterpene lactones. The stereochemical assignments in new compound 1 are based on X-ray diffraction analysis. Compounds 6 and 7 were identified as the known gelomulides A , G . The structures of compounds 7–9 were unambiguously confirmed by X-ray diffraction analyses.

Structural transformation of the sesquiterpene ester, ferutinin (1), by suspended fungal cultures of Aspergillus niger, Rhizopus stolonifer, and Fusarium lini, resulted in the formation of a metabolite. This metabolite was identified as ferutinin α-epoxide (2), by different spectroscopic techniques. Metabolite 2 showed a good antibacterial activity against Staphylococcus aureuscompared to ferutinin (1).

Microbial transformation of mestanolone (1) using the plant pathogenic fungus, Rhizopus stolonifer, resulted in the production of two known metabolites, identified as 11α-hydroxymestanolone (3) and 6α-hydroxymestanolone (4). Transformation of 17-methyl-1-testosterone (2) by R. stolonifer yielded two known metabolites, methandrostenolone (5) and 11α,17β- dihydroxy-androsta-1,4-diene-3-one (6). These transformations included α-hydroxylations at C-11 and C-6, dehydrogenation at C-4, androsta and a demethylation at C-17 positions. Structures of transformed products were determined using spectroscopic techniques.

Salvialeriol ( 1 ), a new abietane-type diterpene, was isolated from Salvia leriifolia Benth. ( Salvia leriaefolia ), along with two known abietane-type diterpenoids, 6-hydroxysalvinolone ( 2 ) and deacetylnemorone ( 3 ), and two known triterpenes, 2-acetoxylupeol ( 4 ), and lupine-2,3-diol ( 5 ). Compounds 2–5 are reported here for the first time from this species. Compound 4 was previously reported as a synthetic derivative of 5 and this is the first report of its isolation from a natural source. Compounds 2 , 3 and 5 exhibited a potent antiproliferative activity against the prostate cancer cell lines (PC3) with IC 50 of 3.9 ± 0.1, 6.2 ± 0.1 and 2.8 ± 0.1 μM, respectively, and cervical cancer cell lines (HeLa) with IC 50 of 8.0 ± 0.3, 2.6 ± 0.1 and 2.7 ± 0.1 μM, respectively. Whereas compounds 1 and 4 showed moderate antiproliferative activities against the cell lines. Compounds 1 – 5 were also evaluated for the inhibition of α-chymotrypsin, a protease enzyme, and 2 exhibited a competitive inhibition of the enzyme (IC 50 = 188.8 μM).

From the leaves of Sarcococca coriacea two new steroidal alkaloids, epoxynepapakistamine-A [(20S)-20-(N-methylamino)-3beta-(tigloylamino)-5alpha-pregna-16alpha,17alpha-epoxy-2beta,4beta-di-O-acetate] (1), and epoxysarcovagenine-D [(20S)-20-(N-methylamino)-3beta-(tigloylamino)-5alpha-pregna-2-en-16alpha,17alpha-epoxy-4-one] (2), and two known compounds funtumafrine C [(20S)-20-(N,N-dimethylamino)-5alpha-pregna-3-one] (3) and N-methylfuntumine (4) were isolated. Their structures were elucidated on the basis of their spectral properties. The compounds 1, 3 and 4 were found to have cholinesterase inhibitory activity when tested for the inhibition of electric eel acetylcholinesterase and horse serum butyrylcholinesterase. They inhibited both enzymes in a concentration dependent fashion.

RATIONALE Tandem mass spectrometric studies of natural products revealed the identification of key fragments which can be helpful for their rapid dereplication in plant extracts utilizing a liquid chromatography/tandem mass spectrometry (LC/MS/MS) approach, particularly for the thermally labile compounds. The knowledge of the collision-induced dissociation (CID) fragmentation pattern of the molecule is essentially required prior to the analysis by LC/MS/MS. METHODS The fragmentation patterns of eleven Buxus steroidal alkaloids were studied by using a positive ion electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QqTOF-MS/MS) hybrid instrument. Chromatographic separation of a Buxus papillosa extract was achieved using a capillary HPLC system coupled with the mass instrument. RESULTS ESI-QqTOF-MS (positive ion mode) showed the presence of several characteristic fragments which can be used to rapidly identify various classes of Buxus steroidal alkaloids. The presence of a cyclopropane ring in the cycloartenol skeleton and the hydroxyl group at C-10 was found to effect on the fragmentation pattern and afford characteristic peaks. This study distinguishes between different types of Buxus steroidal alkaloids based on logical fragmentation pathways. This strategy was successfully applied in LC/ESI-QqTOF-MS/MS analysis of Buxus papillosa extract to investigate and characterize Buxus steroidal alkaloids and 14 compounds were identified as steroidal alkaloids. CONCLUSIONS The knowledge of the fragmentation pattern was used for the rapid identification of this bioactive group of biosynthetically unique steroidal alkaloids in complex plant extracts of Buxus species, especially in the absence of any reference material, by combining key fragments, exact mass measurements and relative abundances of diagnostic fragment ions.

Background Orange peel (Citrus sinensis) and green tea (Camellia sinensis) leaves, rich sources of food flavonoids, were analyzed for their trypsin inhibitory potential. Hesperetin, rutin and hesperidin from orange peel, and catechin from green tea leaves, were isolated and their chemical structures were analyzed. All four compounds were evaluated for their trypsin inhibitory potential. Results Among all the isolated compounds, rutin exhibited the highest protease inhibition activity (75.4 ± 0.9%) with IC50 = 16 ± 2 µmol L−1, followed by catechin (65.3 ± 1.4%; IC50 = 83 ± 9 µmol L−1), hesperetin (62.1 ± 1.3%; IC50 = 104 ± 12 µmol L−1) and hesperidin (59.7 ± 1.1%; IC50 = 127 ± 14 µmol L−1). Lineweaver–Burk and Dixon plots and their secondary replots indicated that all four compounds possessed non-competitive inhibition. The Ki values of hesperetin, rutin, hesperidin and catechin were calculated as 90.2 ± 1.1, 17.5 ± 0.6, 84.2 ± 1.5 and 65.1 ± 1.5 µmol L−1 respectively. Conclusion The present results suggest that the four isolated flavonoids can be used as a supplement in food for the treatment of pathologies associated with the degradation of a specific protein. © 2012 Society of Chemical Industry

Microbial transformation of methasterone (1) was investigated with Macrophomina phaseolina, Cunninghamella blakesleeana, and Fusarium lini. Biotransformation of 1 with M. phaseolina yielded metabolite 2, while metabolites 3-7 were obtained from the incubation of 1 with C. blakesleeana. Metabolites 8-13 were obtained through biotransformation with F. lini. All metabolites, except 13, were found to be new. Methasterone (1) and its metabolites 2-6, 9, 10, and 13 were then evaluated for their immunomodulatory effects against TNF-α, NO, and ROS production. Among all tested compounds, metabolite 6 showed a potent inhibition of proinflammatory cytokine TNF-α (IC50=8.1±0.9μg/mL), as compared to pentoxifylline used as a standard (IC50=94.8±2.1μg/mL). All metabolites were also evaluated for the inhibition of NO production at concentration of 25μg/mL. Metabolites 6 (86.7±2.3%) and 13 (62.5±1.5%) were found to be the most potent inhibitors of NO as compared to the standard NG-monomethyl-l-arginine acetate (65.6±1.1%). All metabolites were found to be non-toxic against PC3, HeLa, and 3T3 cell lines. Observed inhibitory potential of metabolites 6 and 13 against pro-inflammatory cytokine TNF-α, as well as NO production makes them interesting leads for further studies.

Seven metabolites were obtained from the microbial transformation of anabolic-androgenic steroid mibolerone (1) with Cunninghamella blakesleeana, C. echinulata, and Macrophomina phaseolina. Their structures were determined as 10β,17β-dihydroxy-7α,17α-dimethylestr-4-en-3-one (2), 6β,17β-dihydroxy-7α,17α-dimethylestr-4-en-3-one (3), 6β,10β,17β-trihydroxy-7α,17α-dimethylestr-4-en-3-one (4), 11β,17β-dihydroxy-(20-hydroxymethyl)-7α,17α-dimethylestr-4-en-3-one (5), 1α,17β-dihydroxy-7α,17α-dimethylestr-4-en-3-one (6), 1α,11β,17β-trihydroxy-7α,17α-dimethylestr-4-en-3-one (7), and 11β,17β-dihydroxy-7α,17α-dimethylestr-4-en-3-one (8), on the basis of spectroscopic studies. All metabolites, except 8, were identified as new compounds. This study indicates that C. blakesleeana, and C. echinulata are able to catalyze hydroxylation at allylic positions, while M. phaseolina can catalyze hydroxylation of CH2 and CH3 groups of substrate 1. Mibolerone (1) was found to be a moderate inhibitor of β-glucuronidase enzyme (IC50 = 42.98 ± 1.24 μM) during random biological screening, while its metabolites 2-4, and 8 were found to be inactive. Mibolerone (1) was also found to be significantly active against Leishmania major promastigotes (IC50 = 29.64 ± 0.88 μM). Its transformed products 3 (IC50 = 79.09 ± 0.06 μM), and 8 (IC50 = 70.09 ± 0.05 μM) showed a weak leishmanicidal activity, while 2 and 4 were found to be inactive. In addition, substrate 1 (IC50 = 35.7 ± 4.46 μM), and its metabolite 8 (IC50 = 34.16 ± 5.3 μM) exhibited potent cytotoxicity against HeLa cancer cell line (human cervical carcinoma). Metabolite 2 (IC50 = 46.5 ± 5.4 μM) also showed a significant cytotoxicity, while 3 (IC50 = 107.8 ± 4.0 μM) and 4 (IC50 = 152.5 ± 2.15 μM) showed weak cytotoxicity against HeLa cancer cell line. Compound 1 (IC50 = 46.3 ± 11.7 μM), and its transformed products 2 (IC50 = 43.3 ± 7.7 μM), 3 (IC50 = 65.6 ± 2.5 μM), and 4 (IC50 = 89.4 ± 2.7 μM) were also found to be moderately toxic to 3T3 cell line (mouse fibroblast). Interestingly, metabolite 8 showed no cytotoxicity against 3T3 cell line. Compounds 1-4, and 8 were also evaluated for inhibition of tyrosinase, carbonic anhydrase, and α-glucosidase enzymes, and all were found to be inactive.

Acute leukemia is a critical neoplasm of white blood cells. In order to differentiate between the metabolic alterations associated with two subtypes of acute leukemia, acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML), we investigated the serum of ALL and AML patients and compared with two controls (healthy and aplastic anemia) using 1H NMR (nuclear magnetic resonance) spectroscopy. Thirty-seven putative metabolites were identified using Carr-Purcell-Meiboom-Gill (CPMG) sequence. The use of PLS-DA and OPLS-DA models gave results with 84.38% and 90.63% classification rate, respectively. The metabolites responsible for classification are mainly lipids, lactate and glucose. Compared with controls, ALL and AML patients showed serum metabonomic differences involving aberrant metabolism pathways including glycolysis, TCA cycle, lipoprotein changes, choline and fatty acid metabolisms.

A new adduct of abietane-type diterpene, salvialeriicone (1), was isolated from Salvia leriifolia Benth., along with a new chemical entity nor-abietane diterpene, 2-isopropyl-8,8-dimethyl-7,8-dihydrophenanthrene-1,4,5(6H)-trione (2). Their structures were determined using mass spectrometry, and 1D- and 2D-NMR spectroscopy. Salvialeriicone: A new compound from Salvia leriifolia Benth.

Tyramine derivatives 3-27 were synthesized by using conventional and environmental friendly ultrasonic techniques. These derivatives were then evaluated for the first time for their α-glucosidase (Sources: Saccharomyces cerevisiae and mammalian rat-intestinal acetone powder) inhibitory activity by using in vitro mechanism-based biochemical assays. Compounds 7, 14, 20, 21 and 26 were found to be more active (IC50 = 49.7 ± 0.4, 318.8 ± 3.7, 23.5 ± 0.9, 302.0 ± 7.3 and 230.7 ± 4.0 μM, respectively) than the standard drug, acarbose (IC50 = 840.0 ± 1.73 μM (observed) and 780 ± 0.028 μM (reported)) against α-glucosidase obtained from Saccharomyces cerevisiae. Kinetic studies were carried out on the most active members of the series in order to determine their mode of inhibition and dissociation constants. Compounds 7, 20 and 26 were found to be the competitive inhibitors of α-glucosidase. These compounds were also screened for their protein antiglycation, and dipeptidyl peptidase-IV (DPP-IV) inhibitory activities. Only compounds 20, 22 and 27 showed weak antiglycation activity with IC50 values 505.27 ± 5.95, 581.87 ± 5.50 and 440.58 ± 2.74 μM, respectively. All the compounds were found to be inactive against DDP-IV enzyme. Inhibition of α-glucosidase, DPP-IV enzymes and glycation of proteins are valid targets for the discovery of antidiabetic drugs. Cytotoxicity of compounds 3-27 was also evaluated by using mouse fibroblast 3T3 cell lines. All the compounds were found to be noncytotoxic. The current study describes the synthesis α-glucosidase inhibitory activity of derivatives, based on a natural product tyramine template. The compounds reported here may serve as the starting point for the design and development of novel α-glucosidase inhibitors as antidiabetic agents.

Microbial transformation of the anti-inflammatory steroid medrysone (1) was carried out for the first time with the filamentous fungi Cunninghamella blakesleeana (ATCC 8688a), Neurospora crassa (ATCC 18419), and Rhizopus stolonifer (TSY 0471). The objective was to evaluate the anti-inflammatory potential of the substrate (1) and its metabolites. This yielded seven new metabolites, 14α-hydroxy-6α-methylpregn-4-ene-3,11,20-trione (2), 6β-hydroxy-6α-methylpregn-4-ene-3,11,20-trione (3), 15β-hydroxy-6α-methylpregn-4-ene-3,11,20-trione (4), 6β,17α-dihydroxy-6α-methylpregn-4-ene-3,11,20-trione (5), 6β,20S-dihydroxy-6α-methylpregn-4-ene-3,11-dione (6), 11β,16β-dihydroxy-6α-methylpregn-4-ene-3,11-dione (7), and 15β,20R-dihydroxy-6α-methylpregn-4-ene-3,11-dione (8). Single-crystal X-ray diffraction technique unambiguously established the structures of the metabolites 2, 4, 6, and 8. Fungal transformation of 1 yielded oxidation at the C-6β, -11β, -14α, -15β, -16β positions. Various cellular anti-inflammatory assays, including inhibition of phagocyte oxidative burst, T-cell proliferation, and cytokine were performed. Among all the tested compounds, metabolite 6 (IC50 = 30.3 μg/mL) moderately inhibited the reactive oxygen species (ROS) produced from zymosan-induced human whole blood cells. Compounds 1, 4, 5, 7, and 8 strongly inhibited the proliferation of T-cells with IC50 values between

The current study was aimed at investigating the potential antidepressant activity of Areca catechu nut ethanol extract and its various fractions using behavioral (acute and sub-chronic forced swim tests) and biochemical (monoamines and their metabolite levels using high performance liquid chromatography) tests. The areca nut ethanol extract and its aqueous fraction exhibited antidepressant activity in both acute and sub-chronic forced swim tests (IC50 ~ 50 and 20 mg/kg, respectively), which was further confirmed by unaltered locomotor (horizontal and vertical) activities of rats in the activity cage. Phytochemical analysis revealed that saponins of areca nut may be the active component in its antidepressant action. The rats treated sub-chronically with areca nut extract displayed toxic effects, whereas its active aqueous fraction was non-toxic, indicating the presence of different constituents for antidepressant and toxic effects. In the hippocampus of rats, the areca nut extract (50 mg/kg) and aqueous fraction (20 mg/kg) caused a significant elevation of serotonin (around 35%) and noradrenaline (around 30%) compared with the control (261 ± 25 and 512 ± 29 ng/g, respectively). In conclusion, the areca nut possesses potential antidepressant effect via the elevation of serotonin and noradrenaline. Copyright © 2012 John Wiley & Sons, Ltd.

Rapid characterization of 23 pregnane-type steroidal alkaloids was studied using a positive ion electrospray ionization quadropole time-of-flight mass spectrometry (ESI-QqTOF-MS/MS) hybrid instrument. ESI-QqTOF-MS (positive ion mode) showed the presence of the protonated molecules [M+H](+) which through low-energy collision-induced dissociation tandem mass spectrometric (CID-MS/MS) analysis showed the characteristic loss of dimethylamine moiety [M+H-45](+) followed by the sequential lossess of attached substituents. Steroidal alkaloids having tigloyl or senecioyl group at C-3 produced diagnostic fragment ions at m/z 100 and 83. Our study also demonstrates the influence of unsaturation, and number and nature of substitutents on product ion abundance and fragment ions. Moreover, the generalization of the fragmentation pattern was linked with the structural features in steroidal skeleton. This strategy was successfully applied in LC-ESI-QqTOF-MS/MS analysis of Sarcococca coriacea extract to investigate and characterize pregnane-type steroidal alkaloids in complex mixture.

An isomer of the natural phthalate ester spatozoate (1), n-butyl 2-benzoyloxymethylbenzoate (2a) and a series of its new derivatives 2b–2s were synthesized and exposed to selected biological screening, as phthalates were reported to possess different biological activities. Compound 2g was found to be the most potent cytotoxic agent with a LD 50 = 8.98 µg/ml. In a bactericidal assay the compounds showed a broad spectrum of activities. Compound 2a has a very promising fungicidal activity against Microsporum canis .

Lichens are unique individuals which have been widely used in traditional medicines. This study was focused on the bioassay-guided phytochemical investigation, and bioactivity evaluation on a lichens species, Parmotrema cooperi. This first bioassay-directed chemical study on P. cooperi has led to the isolation of ethyl heamatomate (1), atraric acid (2), ethyl orsellinate (3), orsellinic acid (4), lecanoric acid (5), gyrophoric acid (6), and licanorin (7). The structures of 1–7 were mainly elucidated from spectroscopic methods including 1D, and 2D NMR spectroscopy, and mass spectrometry. These compounds were evaluated for their antiglycation, urease, α-chymotrypsin, and β-glucoronidase inhibitory activities. Few of the phenolic compounds showed significant, while most of them showed good inhibition of protein glycation, and urease activities.

Microbial transformation of (20S)-20-hydroxymethylpregna-1,4-dien-3-one (1) by four filamentous fungi, Cunninghamella elegans, Macrophomina phaseolina, Rhizopus stolonifer, and Gibberella fujikuroi, afforded nine new, and two known metabolites 2–12. The structures of these metabolites were characterized through detailed spectroscopic analysis. These metabolites were obtained as a result of biohydroxylation of 1 at C-6β, -7β, -11α, -14α, -15β, -16β, and -17α positions, except metabolite 2 which contain an O-acetyl group at C-22. These fungal strains demonstrated to be efficient biocatalysts for 11α-hydroxylation. Compound 1, and its metabolites were evaluated for the first time for their cytotoxicity against the HeLa cancer cell lines, and some interesting results were obtained.

A high performance thin-layer chromatographic (HPTLC) method for the simultaneous determination of the hypolipidemic agents, E - and Z -isomers of guggulsterone in Commiphora mukul resin, guggulipid (ethyl acetate extract of resin), and its pharmaceutical formulation, was developed. The developed system was efficient enough to separate both isomers from their conger, 17,20-dihydroguggulsterone ( 3 ). HPTLC glass plates, pre-coated with silica gel 60F-254, were used as a stationary phase. The mobile phase consisted of toluene:acetone (9.3:0.7, v/v) which gave well resolved spots for E - and Z -guggulsterones ( R f : 0.52 ± 0.01, and 0.67 ± 0.01, respectively) following double development of chromatoplate with the same mobile phase under unsaturated conditions. The analyte stability towards the developed chromatographic procedure was also investigated by two-dimensional (2D) HPTLC analysis. 17,20-Dihydroguggulsterone ( 3 ) was identified by the electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI–QTOF–MS/MS) analysis.

Natural products have been a rich source of lead identification for drug discovery and development. Over the last two decades, the impetus for natural product-based lead discovery in pharmaceutical industry has declined, resulting in a productivity and innovation crisis. Most of the focus is now on high-throughput screening of synthetic libraries of compounds against defined biological targets; however, discovery of new molecular entities (NMEs) is still declining in this postgenomic era. With the availability of modern purification, characterization, and yield optimization techniques, and with an established intellectual property rights (IPR) regime, it is now possible to circumvent the problems once associated with natural product-based drug discovery. Our work demonstrates that natural products can lead to cost-effective identification of lead molecules against a defined molecular target. During our recent studies, novel classes of urease and α-glucosidase inhibitors were initially obtained from medicinal plants, and based on these novel structural leads, synthetic libraries of structural analogues were synthesized for structure–activity relationship (SAR) studies. These synthetic analogues have shown potent inhibitory activities against the target enzymes, and their mechanisms of action were studied by kinetic, computational, and NMR-based methods.