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Drug-resistant Pseudomonas aeruginosa efflux pump extrudes antibiotics from cells for survival. Efflux pump inhibitor (EPI) thus becomes an interesting alternative to handle the drug-resistant bacteria. Conessine, a natural steroidal alkaloid from Holarrhena antidysenterica, previously exhibited efflux pump inhibitory potential. Our molecular docking and molecular dynamics (MD) studies provided atomistic information as well as the interaction of conessine with bacterial MexB efflux pump in phospholipid bilayer membrane to further the previous experimental report. Herein, the binding site and proposed mode of action of conessine were identified compared to known/commercial EPIs such as PAβN or designed-synthetic P9D. Our results explained conessine binding mode of action as an effective agent against the MexB efflux pump. The MD simulation also suggested that conessine was able to affect glycine loop (G-loop) flexibility, and the reduced G-loop flexibility due to conessine could hinder an antibiotics extrusion. In addition, our study suggested the conessine core structure buried in a hydrophobic region in the efflux pump similar to other known EPIs. Our finding could cope as a key for the design and development of the conessine derivative as novel EPI against P. aeruginosa.Communicated by Ramaswamy H. Sarma.

Objectives: Epidemiological data suggests the highest density of histamine H3-receptors (H3R) in basal ganglia of central nervous system (CNS) wherein they function as inhibitory auto-receptors and control the release of many neurotransmitters. Inhibition of H3R increases the turnover of neurotransmitters, especially dopamine in basal ganglia and could be beneficial to treat Parkinson’s disease. Methods: In this study, we formulated the brain targeting liposomes of conessine, a selective antagonist for H3R to increase bioavailability and developed and validated a rapid and sensitive reverse phase ultra-force liquid chromatographic (RP-UFLC) method and to quantitate conessine in Wistar rat plasma and tissue. Plasma and tissue samples were extracted by protein precipitation technique using acetonitrile (ACN) and aripiprazole as the internal standard. Chromatographic separation was performed on the Hibar C18 column with a mobile phase of Hexane Sulphonic acid (10 mM, pH 10.0 adjusted with ammonia) and methanol at a flow rate of 0.9 ml/min. Results: The lower limit of quantification of the developed method was 4.0 ng/ml and 6.0 ng/g in plasma and tissue samples, respectively. Liposomes of conessine (equivalent to 20 mg/kg) administered orally to animals, demonstrated remarkable absorption into the systemic circulation with maximum concentration (~8700 ng/ ml) within 2.0 h. The order of area under curve was found to be kidney> brain> liver> lungs> spleen> heart. Conclusion: The liposomes of conessine were rapidly taken up into the brain and showed a good brain concentration after 2.0 h; sustenance up to 4.0 h was achieved which is better than conessine solution. Key words: Conessine, RP-UFLC method, Pharmacokinetic, Tissue distribution, Validation.

Ornithine decarboxylase (ODC) is an immediate precursor of polyamine biosynthesis in Serratia marcescens and a potential target for inhibition of its growth. We predicted the 3D structural conformation of ODC enzyme and validated it using MDS in our previous study. In this current study, the potential inhibitors of ODC were obtained by virtual screening of potential inhibitors from ZINC database and studied in depth for their different binding pose. Among the ten virtually screened inhibitors, Conessine exhibited the best binding with ODC and its inhibition property was studied further by MDS studies. The natural compound conessine is isolated from plant Holarrhena antidysenterica and it is studied against ODC of Serratia marcenses for its inhibitory potentials. This revealed unforeseen twisted position in root mean square fluctuation (RMSF) and ODC modelled conformation that influenced ligand binding. Both predicted model and ligand bound model were compared and found to be stable with Root Mean Square Deviation (RMSD) of approximately 7 nm and 0.25 nm to that of crystallographic structure over simulation time of 55 ns and 70 ns respectively. This work paves the way for future development of new drugs against nosocomial diseases caused by Serratia marcescens.

Holarrhena pubescens is an important medicinal plant of the Apocynaceae family that is widely distributed over the Indian subcontinent. The plant is extensively used in Ayurveda and other traditional medicinal systems without obvious adverse effects. Beside notable progress in the biological and phytochemical evaluation of this plant over the past few years, comprehensive reviews of H. pubescens are limited in scope. It has economic importance due to the extensive use of seeds as an antidiabetic. Furthermore, the plant is extensively reported in traditional uses among the natives of Asia and Africa, while scientifical validation for various ailments has not been studied either in vitro or in vivo. This review aims to summarize information on the pharmacology, traditional uses, active constituents, safety and toxicity of H. pubescens. Chemical analysis of H. pubescens extracts revealed the presence of several bioactive compounds, such as conessine, isoconnessine, conessimine, conimine, conessidine, conkurchicine, holarrhimine, conarrhimine, mokluangin A-D and antidysentericine. Overall, this review covers the ethnopharmacology, phytochemical composition, and pharmacological potential of H. pubescens, with a critical discussion of its toxicity, biological activities (in vitro and in vivo), the mechanism of action, as well as suggestions for further basic and clinical research. ispartof: BIOMOLECULES vol:10 issue:9 ispartof: location:Switzerland status: published

The majority of indigenes in the rural areas of Ghana use herbal medicines for their primary health care. In this study, an ethnobotanical survey was undertaken to document medicinal plants used by traditional healers in the Ejisu-Juaben district in the Ashanti region of Ghana to treat infections and to further investigate the antibiofilm formation properties of selected plants in resisting pathogenic bacteria. Seventy medicinal plants used by traditional practitioners for the treatment of skin infections and wounds were documented from the ethnobotanical survey. Forty out of the seventy plants were collected and their methanol extracts evaluated for antimicrobial activity by the agar diffusion assay. Extracts that showed antibacterial activity were tested for biofilm inhibitory activity, and the most active plant was subsequently purified to obtain the active constituents. Biofilm formation was significantly mitigated by petroleum ether, ethyl acetate, and methanol extracts of Holarrhena floribunda stem bark. Bioassay-guided fractionation of an alkaloidal extract prepared from the methanol fraction led to the isolation of three steroidal alkaloids, namely, holonamine, holadienine, and conessine. The isolated compounds demonstrated varying degrees of biofilm formation inhibitory properties. The current study reveals that screening of indigenous medicinal plants could unravel potential leads to salvage the declining efficacy of conventional antibiotics. Holarrhena floribunda stem bark extract has strong biofilm formation inhibition properties, which could be attributed to the presence of steroidal alkaloids.

It is native to central and southern Africa, the Indian subcontinent, Indochina, and parts of China. Bark is bitter, stomachic, astringent, powerful antidysenteric, febrifuge and anthelmintic, and constitutes the principal medicine for dysentery in all systems of traditional Indian medicine. The bark is one of the most important drugs in Hindu Materia Medica, and is described as astringent, cold and digestive, and is a remedy for piles, dysentery, leprosy and phlegmatic humours. Sushruta said it is expectorant, an antidote to poisons, cures dysuria, urinary and skin diseases, checks nausea and vomiting, allays pruritus, improves the condition of bad ulcers, relieves stomach pain and checks the derangement of three humours, i.e. phlegm, air and bile. According to Charaka and Sushruta, every part of the plant except the flower is used as a snakebite remedy; certain authors have disputed this property. Seeds are cooling, appetizer, astringent, anthelmintic, analgesic and used for leprosy, burning sensations, dysentery, skin diseases, biliousness, bleeding piles, fatigue and hallucinations. In Portugese traditional medicine, the bark is used as plaster in rheumatism, hot decoction is used against toothache and bowel affections and the root-bark is used in chronic fevers. Kurchi contains numerous steroidal alkaloids, including norconessine, isoconessine, and kurchine. Conessine hydrobromide is obtained from seeds. Alkaloidal contents seasonally vary in different parts, and in the bark during different stages. Steroidal alkaloids, conessine, conessimine, conarrhimin and conimine show strong AChE inhibitory activity, conessimine being the strongest. In a clinical trial of 40 Indian patients with 15 patients stool positive for E. histolytica cysts, 20 for G. lamblia and five for both, the bark powder for 15-days significantly improved symptoms and stools negative for E. histolytica cyst in 70% cases.

The compound crystallizes in the orthorhombic crystal system with space group P212121 having unit cell parameters: a=10.840(13), b=10.896(6), c=18.903(6) A and Z=4. The crystal structure was solved by direct method using single crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedures to a final R-value of 0.062 for 1044 observed reflections.

In vitro elicitation of an important compound conessine has been done in the bark-derived callus culture of Holarrhena antidysenterica (L.) Wall. employing different elicitors. For induction of callus, green bark explants excised from field-grown plants were cultured on MS medium augmented with different concentrations (0, 1, 2.5, 5, and 10 μM) of various growth regulators such as BA, IBA, NAA, and 2,4-D either alone or in combinations. The maximum amount of conessine (458.18 ± 0.89d μg/g dry wt.) was achieved in callus developed on MS medium supplemented with 5 μM BA and 5 μM 2,4-D through HPLC analysis. Elicitation in conessine content in the above callus was achieved employing a variety of organic (phenylalanine, tyrosine, chitosan, tryptophan, casein hydrolysate, proline, sucrose, and yeast extract) as well as inorganic elicitors (Pb(NO3)2, As2O3, CuSO4, NaCl, and CdCl2) in different concentrations. The optimum enhancement in conessine content (3518.58 ± 0.28g μg/g dry wt.) was seen at the highest concentration (200 mg/L) of phenylalanine. The enhancement was elicitor specific and dose dependent. The overall increment of the conessine content was seen in the order of phenylalanine > tryptophan > Pb(NO3)2 > sucrose > NaCl > As2O3 > casein hydrolysate > CdCl2 > chitosan > proline > yeast extract > CuSO4 > tyrosine. The isolation and purification of conessine was done using methanol as a solvent system through column chromatography (CC) and TLC. The isolated compound was characterized by FT-IR, 1H-NMR, and HRMS which confirmed with the structure of conessine. The bioassays conducted with the isolated compound revealed a strong larvicidal activity against Anopheles stephensi Liston with LC50 and LC90 values being 1.93 and 5.67 ppm, respectively, without harming the nontarget organism, Mesocyclops thermocyclopoides Harada, after 48 h of treatment. This is our first report for the isolation and elicitation of conessine in the callus culture of H. antidysenterica.

Background Starting December 2019, mankind faced an unprecedented enemy, the COVID-19 virus. The world convened in international efforts, experiences and technologies in order to fight the emerging pandemic. Isolation, hygiene measure, diagnosis, and treatment are the most efficient ways of prevention and intervention nowadays. The health organizations and global care systems screened the available resources and offered recommendations of approved and proposed medications. However, the search for a specific selective therapy or vaccine against COVID-19 remains a challenge. Methods A literature search was performed for the screening of natural and derived bio-active compounds which showed potent antiviral activity against coronaviruses using published articles, patents, clinical trials website (https://clinicaltrials.gov/) and web databases (PubMed, SCI Finder, Science Direct, and Google Scholar). Results Through the screening for natural products with antiviral activities against seven types of the human coronavirus, extracts of Lycoris radiata, Gentiana scabra, Dioscorea batatas, Cassia tora, Taxillus chinensis Cibotium barometz and Echinacea purpurea showed a promising effect against SARS-COV. Out of the listed compound Lycorine, emetine dihydrochloride hydrate, pristimerin, harmine, conessine, berbamine, 4`-hydroxychalcone, papaverine, mycophenolic acid, mycophenolate mofetil, monensin sodium, cycloheximide, oligomycin and valinomycin show potent activity against human coronaviruses. Additionally, it is worth noting that some compounds have already moved into clinical trials for their activity against COVID-19 including fingolimod, methylprednisolone, chloroquine, tetrandrine and tocilizumab. Conclusion Natural compounds and their derivatives could be used for developing potent therapeutics with significant activity against SARS-COV-2, providing a promising frontline in the fighting against COVID-19., Graphical Abstract Image, graphical abstract

Two new steroidal alkaloids, isoconkuressine and N-formylconessimine, together with 6 known steroidal alkaloids including conkuressine, conessine, isoconessimine, conimine, conarrhimine, and funtudienine, were isolated from the seeds of Holarrhena antidysenteriaca Wall.ex A.DC. Their intrinsic antibacterial activities and synergistic effects with penicillin and vancomycin were analyzed in methicillin sensitive staphylococcus aureus (MSSA) and methicillin resistant staphylococcus aureus (MRSA). Two of the steroidal alkaloids including one new compound (N-formylconessimine) showed potential antibacterial activity and possessed synergistic effects with penicillin and vancomycin, respectively.

The adsorption and corrosion inhibitive effect of the ethanol extract of Funtumia elastica (FE) leaves on mild steel corrosion in 0.5 M H2SO4 was studied using gravimetric, potentiodynamic polarization and electrochemical impedance spectroscopic techniques. As well as Fourier transform infrared spectroscopy and computational methods. The gravimetric and electrochemical studies revealed that FE is an adsorption inhibitor. The potentiodynamic polarization result showed that the inhibitor is a mixed type corrosion inhibitor for mild steel in 0.5 M H2SO4, inhibiting both the cathodic and anodic partial reactions. Density functional theory calculations were performed to model the electronic structures of some selected extract constituents (conessine, and ascorbic acid) to confirm their inhibiting potential and established their individual contributions to the observed inhibiting effects.

Emergence and spread of antibiotic-resistant Acinetobacter baumannii have become a major public health concern. This study was designed to investigate the efficacy of Holarrhena antidysenterica extract and its major steroidal alkaloid conessine as resistance-modifying agents (RMAs) on the susceptibility of A. baumannii to novobiocin and rifampicin. A significant synergistic activity of both the extract and conessine in combination with either novobiocin or rifampicin with fractional inhibitory concentration index ≤0.5 was demonstrated. Fluorescent dyes and different efflux pump inhibitors were used to further investigate the synergism. Increase in the uptake of 1-N-phenylnaphthylamine in the bacterial cells treated with the extract and conessine was not observed indicating that both substances did not act as permeabilizers. With regard to efflux pump inhibition, no accumulation in ethidium bromide (EtBr) was noticed suggesting that the AdeABC pump was not involved. In contrast, accumulation in Pyronin Y was significantly increased (p 0.05) demonstrating that the synergism was due to interference with the AdeIJK pump. Study on frequencies of the spontaneous mutational resistance to the extract in combination with antibiotics demonstrated attenuation in drug-resistant organisms. Thus, H. antidysenterica extract and conessine as RMAs may offer a combinatory therapy to restore antibiotic susceptibility in the extensively drug-resistant A. baumannii.

This work was supported by the Thailand Research Fund through the Royal Golden Jubilee Ph.D. Program (Grant No. PHD/0041/2556) co-funded by the Newton Fund of the British Council and TRF Senior Research Scholar (Grant No. RTA 5880005). Background This study aimed to evaluate the efficacy of combinations of steroidal alkaloids and conessine from the Thai medicinal plant Holarrhena antidysenterica with antibiotics against Pseudomonas aeruginosa strains possessing different efflux-pump-mediated multidrug-resistant (MDR) phenotypes in a Galleria mellonella infection model. Methods P. aeruginosa strains with defined mutations that result in the overexpression of the MexAB-OprM, MexCD-OprJ and MexEF-OprN efflux pumps, and a strain with all three of these pumps deleted, were used. In vitro, the effect of combinations of steroidal alkaloids and conessine with antibiotics was compared with antibiotic treatment alone via MIC determination and time-kill assays. Efficacy of combinations of the steroidal alkaloids and conessine with levofloxacin were compared with monotherapies against infections in G. mellonella larvae by measuring larval mortality and bacterial burden. Results Combination therapies of conessine or steroidal alkaloids with levofloxacin enhanced bacterial inhibition in vitro and restored antibiotic efficacy in vivo compared to the constituent monotherapies. Neither conessine nor the steroidal alkaloids induced any detectable toxicity in G. mellonella larvae. The enhanced efficacy of the combination treatments was most pronounced with conessine and correlated with reduced larval burden of infecting P. aeruginosa. Notably, the enhanced efficacy of conessine/levofloxacin combinations was only detected in the parent strain and strains that overexpressed the MexAB-OprM or MexEF-OprN efflux systems. Conclusions Steroidal alkaloids from Holarrhena antidysenterica, and particularly the principal active ingredient conessine, restored levofloxacin efficacy against resistant P. aeruginosa strains possessing efflux-mediated MDR phenotypes. The compounds should be investigated further as a potential novel therapy. Publisher PDF

Conessine, a steroidal alkaloid, is a potent histamine H3 antagonist with anti-malarial activity. We recently reported that conessine treatment interferes with H₂O₂-induced cell death by regulating autophagy. However, the cellular signaling pathways involved in conessine treatment are not fully understood. Here, we report that conessine reduces muscle atrophy by interfering with the expression of atrophy-related ubiquitin ligases MuRF-1 and atrogin-1. Promoter reporter assay revealed that conessine treatment inhibits FoxO3a-dependent transcription, NF-kappaB-dependent transcription and p53-dependent transcription. We also showed that conessine treatment reduced dexamethasone-induced expression of MuRF1 and atrogin-1 by the quantitative RT-PCR and Western blot. Finally, we demonstrated that conessine treatment reduced dexamethasone-induced muscle atrophy using differentiated C2C12 cells. These results collectively suggest that conessine is potentially useful in the treatment of muscle atrophy.

N-Nitrosodimethylamine (NDMA) is a potent carcinogen and can be produced during chloramination of drinking water and wastewater. Computational chemistry methods were used for the first time to calculate molecular descriptors for 64 NDMA precursors containing a dimethylamine (DMA) moiety. Descriptors were partial charge, bond length and pKa of the DMA nitrogen and planarity of the DMA group. Precursors classified on the basis of chemical functionality showed distinct relationships between partial charge and NDMA formation. Quaternary amines and tertiary amines with the DMA bonded to -COR and -CSR groups had a combination of low NDMA formation and high partial charge. The most potent NDMA precursors are tertiary amines with an acidic hydrogen and electron-donating group α and β to the DMA respectively. They also have comparable molecular descriptors: relatively negative partial charges, low planarity values, high bond lengths and pKa values from ∼8.3–10.1. A literature search identified 233 potential NDMA precursors that have never been tested experimentally. Of these chemicals 60% are therapeutics, 13% veterinary therapeutics and 10% natural products. Analysis combining qualitative assessment of chemical functionality and computational calculation of molecular descriptors successfully identified rivastigmine, a therapeutic, and conessine, a naturally occurring species, whose NDMA yields were determined experimentally to be 83.3 ± 0.5% and 42.3 ± 1.8% mol mol−1, respectively. This study defines the molecular properties associated with reactive NDMA precursors and the origin and identity of those amines which contribute to NDMA formation in drinking water.

This work reports the activity (at various conditions) of conessine isolated from methanolic extract of Holarrhena floribunda, on the inhibition of the germination of two Bacillus spores species. This activity was studied by treating spores of Bacillus cereus T and Bacillus stearothermophilus CNCH 5781 with effective concentrations of conessine at various temperature, pH and treatment times. The inhibition of germination was evaluated by the culture of treated spores on agar medium and the number of colony obtained was compared with that of control culture (not treated with conessine). We found that conessine used at 50 and 100 µg/ml for 20 min each decreased considerably the germination of spore of B. cereus T and B. stearothermophilus CNCH 5781. The maximum temperature of conessine activity for B. cereus T was at 30 and 60°C for B. stearothermophilus CNCH 5781 spores. Furthermore, the activity of conessine was sensitive to pH change and was more effective at pH 6 on both bacterial spore strains. The treatment of spores with conessine at various lengths of time demonstrated that, the activity of the compound on both bacterial spores was strongly related to the bacterial species. This study suggested that the activity of conessine on the inhibition of germination of Bacillus spore depends on physico-chemical factors and the bacterial species.

New isoconessimine derivatives were synthesized from conessine (1) and evaluated as acetylcholinesterase (AChE) inhibitors. The derivatives were prepared via two reaction steps, N-demethylation and nucleophilic substitution. All of the synthesized derivatives exhibited more potential anti-acetylcholinesterase activities than conessine (1) (IC50=16 mu molL(-1)) and isoconessimine (2) (IC50>300 mu molL(-1)). Compound 7b (3-[methyl-[2-(4-nitrophenoxy)ethyl]amino]con-5-enine) showed the most potent inhibitory activity with an IC50 of 110 nmol/L which is close to that of reference compound huperzine A (IC50=70 nmol/L). The mode of AChE inhibition by 7b was reversible and non-competitive. In addition, molecular modeling was performed to explore the binding mode of inhibitor 7b at the active site of AChE and the results showed that 7b could be docked into the acetylcholinesterase active site and compound 7b had hydrophobic interactions with Trp279 and Leu282.

Medicinal plants are generating an ever-increasing amount of interest due to the effectiveness, low cost and minimal side-effects associated with drugs derived from them. Holarrhena antidysenterica (syn. H. pubescens) WALL., belonging to the family Apocynaceae, is commended for the medicinal applications of its stem bark, leaves and seeds in Ayurveda. During the past century, studies on the phytochemical and pharmacological nature of the plant have yielded important results regarding the chemical constituents present and have also verified the traditionally claimed properties associated with the plant viz. analgesic, antibacterial, anti-diarrhoeal, anti-amoebic, anti-inflammatory and anti-haemorrhoidal activities. Moreover, recently some other properties have also been discovered viz. anti-malarial, anti-diabetic, anti-oxidant, anti-urolithic, anti-mutagenic, CNS-stimulating, Angiotensin-converting-enzyme inhibitory and acetylcholinesterase inhibitory activity. This review discusses the findings of studies on the aforementioned properties of the plant in detail and 68 alkaloids isolated from various parts of plant to justify its widespread use in the treatment of a variety of diseases and suggests future lines of research.

DMNG-3 (3β-Methyl-[2-(4-nitrophenoxy)ethyl]-amino]con-5-enine), is a new and the potentially most potent acetylcholinesterase inhibitor recently obtained from conessine by N-demethylation and nucleophilic substitution reaction. In the present study, a step‑down passive avoidance test was used to investigate whether DMNG-3 could modulate impairment of learning and memory induced by scopolamine, and a high performance liquid chromatography (HPLC) method for the determination of DMNG-3 in biological samples was applied to study its pharmacokinetics and tissues distribution. Separation was achieved on C18 column using a mobile phase consisting methanol‑water (70:30, v/v) at a flow rate of 1.0 ml/min. The intra- and inter-day precisions were good and the RSD was all lower than 1.30%. The mean absolute recovery of DMNG-3 in plasma ranged from 88.55 to 96.45%. Our results showed oral administration of DMNG-3 (10, 25, 50 mg/kg/day) can significantly improve the latency and number of errors and had a positive effect of improvement of learning and memory in mice in passive avoidance tests. The elimination half-life (T1/2) was 14.07±1.29, 15.87±1.03 h, and the total clearance (CL) values were 0.70±0.11, 0.78±0.13 L/h/kg, respectively. The pharmacokinetic studies showed that DMNG-3 has a slowly clearance and large distribution volume in experimental animals, and its disposition is linear over the range of doses tested. The liver, small intestine, stomach, and large intestine were the major distribution tissues of DMNG-3 in mice. It was found that DMNG-3 could be detected in brain, suggesting that DMNG-3 can cross the blood-brain barrier. The present study shows that DMNG-3 can be possible developed as a new drug for the treatment of Alzheimer's disease in the future.

Vidangarista is an ayurvedic polyherbal formulation officially recorded in the Ayurvedic formulary of India and used as an anthelmintic. The herbal formulation contains many plant constituents, and hence a large number of markers should be quantified to assess its quality. This paper reports the standardization of Vidangarista by HPTLC analysis for the presence of the biomarkers gallic acid and conessine. Each marker compound showed a linear relationship with an average r2 = 0.99 in the concentration range studied. The proposed method was found to be precise, specific, and accurate, with a recovery of 99–101%, and hence can be used for routine analysis of this formulation.

Made available in DSpace on 2018-12-11T16:41:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-05-15 Ethanol abuse potential is mainly due to its reinforcing properties, crucial in the transition from the recreational to pathological use. These properties are mediated by mesocorticolimbic and nigrostriatal dopaminergic pathways and neuroadaptations in these pathways seem to be responsible for addiction. Both pathways are modulated by other neurotransmitters systems, including neuronal histaminergic system. Among the histamine receptors, H3 receptor stands out due to its role in modulation of histamine and other neurotransmitters release. Thus, histaminergic system, through H3 receptors, may have an important role in ethanol addiction development. Aiming to understand these interactions, conessine, an H3 receptor antagonist, was given to mice subjected to the evaluation of ethanol-induced psychostimulation, ethanol CPP and quantification of norepinephrine, dopamine, serotonin and their metabolites in mesocorticolimbic and nigrostriatal pathways following acute ethanol treatment. Systemic conessine administration exacerbated ethanol effects on locomotor activity. Despite of conessine reinforcing effect on CPP, this drug did not alter acquisition of ethanol CPP. Ethanol treatment affects the serotoninergic neurotransmission in the ventral tegmental area, the dopaminergic neurotransmission in the pre-frontal cortex (PFC) and caudate-putamen nucleus (CPu) and the noradrenergic neurotransmission in the CPu. In the PFC, conessine blocked ethanol effects on dopaminergic and noradrenergic neurotransmission. The blockade of H3 receptors and ethanol seem to interact in the modulation of dopaminergic neurotransmission of nigrostriatal pathway, decreasing dopamine metabolites in substantia nigra. In conclusion, conessine was able to change psychostimulant effect of ethanol, without altering its reinforcing properties. This exacerbation of ethanol-induced psychostimulation would be related to alterations in dopaminergic neurotransmission in the nigrostriatal pathway. Laboratory of Pharmacology School of Pharmaceutical Sciences Univ Estadual Paulista-UNESP Joint Graduate Program in Physiological Sciences UFSCar/UNESP Institute of Biomedical Sciences Federal University of Uberlândia (UFU) Laboratory of Pharmacology School of Pharmaceutical Sciences Univ Estadual Paulista-UNESP Joint Graduate Program in Physiological Sciences UFSCar/UNESP

Ornithine decarboxylase (ODC) enzyme, catalyses the decarboxylation of ornithine to form spermidine which is a committed step in the biosynthesis of polyamines. Here, in the present work, structure of ODC was modelled and studied for its active site. The stability of modelled structure was revalidated by the molecular dynamics simulation at 50 nano second time scale. 142 Natural products of Indofine Herbal Ingredient library from ZINC database were screened using Autodock Vina for the identification of potential leading herbal inhibitors. The results obtained from docking showed that Conessine is best inhibiting candidate with docking affinity of –9.7 Kcal/mol. Conessine is an alkaloid which proves its immense importance as metabolites. Thus, polyamine being harmful when synthesised in excess are necessary to be controlled at their genesis. Therefore, conessine might be a potential inhibitor for toxicity control in plant growth promoting rhizobacteria.

A new series of H 3 antagonists derived from the natural product Conessine are presented. Several compounds from these new series retain the potency and selectivity of earlier diamine based analogs while exhibiting improved PK characteristics. One compound ( 3u ) demonstrated functional antagonism of the H 3 receptor in an in vivo pharmacological model.

Construction of quaternary carbons is a challenge in PK chemistry, with few precedents in the literature. Starting from suitable functionalized enynes including an aromatic ring that templates the reaction, polycyclic ketones are obtained with a quaternary carbon. Special reaction conditions are necessary including the use of molecular sieves and co-catalysis with rhodium complexes jointly with cobalt carbonyl. The products obtained are intermediates in the synthesis of various natural products like the Hamigeran family and the steroidic alkaloid Conessine.

A selective, precise, and accurate high-performance thin-layer chromatographic (HPTLC) method has been proposed for the analysis of conessine in Holarrhena antidysenterica. The method involves visible densitometric evaluation of conessine resolving it by HPTLC on aluminium-based silica gel plates. For visible densitometric evaluation, peak areas were recorded at 520 nm after the resolved bands were derivatized with Dragendorff's reagent and then sprayed with a 10 solution of aqueous sodium nitrite which resulted in reddish brown color. The correlation between the concentration and area was found to be linear within the range of 10 to 60 ng/spot. The method was validated for precision (interday and intraday), repeatability, and accuracy. Mean recovery for conessine was 98.34100.25. The method was applied for the quantitation of conessine in Kurchi. The proposed HPTLC method was found to be precise, specific, sensitive, and accurate and can be used for routine analysis of Kurchi.

Aim: Potential herbal leads as novel therapeutic alternatives against Multi-Drug Resistant Salmonella enterica serovar typhimurium were investigated and validated by mol inspiration. Methodology: The present study utilizes an in silico ‘Herbal Informatics’ model which deploys dynamic search protocols, priority indexing and systemic categorization for rationale based selection of nutraceuticals targeting the critical virulence factors of Multi-Drug Resistant Salmonella enterica serovar typhimurium. Furthermore, in silico biochemical activity prediction was conducted using ‘Mol inspiration’ chemiinformatics tool, so as to propose the drug likeliness of selected natural plant products. Results: Out of the 05 selected bioactivity parameters of Salmonella enterica, lipo-polysaccharide inhibition exhibited maximum relevance as physiological target i.e., 65%, followed by other parameters like enterochelin inhibition, Type III secretory system inhibition, Superoxide dismutase inhibition and Symptomatic relief provision. The binary matrix analysis of database of 50 plants identified using classical bioprospection filtered 28 herbals which exhibited probable potential to mitigate 03 or more virulence factors. The weightage matrix analysis further scrutinized the selection upto 10 herbals having a score more than median weightage matrix score i.e., 14.98. The optimization of data on a scale of 0-1 using fuzzy score matrix analysis led to the final selection of 10 herbals i.e., Abrus precatorius, Azadirachta indica, Camellia sinensis, Holarrhena antidysenterica, Andrographis paniculata, Adhatoda vasica, Euphorbia hirta, Ocimum sanctum, Terminalia arjuna and Terminalia belerica. In silico Bioactivity prediction analysis of predominant phytoconstituents of selected herbals revealed Holarrhena antidysenterica (Conessine), Andrographis paniculata (Andrographolide), Euphorbia hirta (Amyrin) and Terminalia arjuna (Arjunolic acid) exhibiting drug likeliness with their targeted action as a GPCR Ligand, Nuclear Receptor Ligand or Protease inhibitor.

International audience; Bioassay-guided fractionation of the EtOH extract of the stem bark of Funtumia elastica resulted in the isolation of four steroidal alkaloids, holarrhetine (1), conessine (2), holarrhesine (3) and isoconessimine (4). Their structures were determined on the basis of 1D- and 2D-NMR techniques and mass spectrometry. Compounds 1-4 exhibited in vitro antiplasmodial activity against the chloroquine-resistant strain FcB1 of Plasmodium falciparum with IC50 values ranging from 0.97 to 3.39 microM. They showed weak cytotoxicity against a rat cell line L-6 with IC50 values ranging from 5.13 to 36.55 microM.

The steroidal alkaloid 3β, 20α-diamino-pregn-5-ene (kurchamine) obtained from the stem bark of Holarrhena antidysenterica is reported to have appreciable amoebicidal activity. Its three stereoisomers namely 3α, 20β-diamino-pregn-5-ene, 3β, 20β-diamino-pregn-5-ene and 3α,20α-diamino-pregn-5-ene and their intermediate stereoisomeric monoamino pregnene alkaloids namely 3β-amino-pregn-5-ene-20-one, 3α-amino-pregn-5-ene-20-one, 20α -amino-pregn-5-ene-3β-ol, 20β-amino-pregn-5-ene-3β-ol were synthesized. The natural stereoisomer and synthesized diamino and monoamino stereoisomers were N-methylated and all the compounds were evaluated for amoebicidal activity comparison. The natural stereoisomer 3β,20α-diamino-pregn-5-ene (kurchamine) was found to be superior than other stereoisomers and N-methylation was found to have insignificant effect on amoebicidal activity of stereoisomers.