Day 2 :
Keynote Forum
Yahdiana Harahap
Universitas Indonesia, Indonesia
Keynote: Bioanalytical method development and its validation are significant in conducting bioequivalence study
Time : 10:00-11:00
Biography:
Yahdiana harahap completed her PhD from Pharmacy Department, Faculty of Mathematics and Natural Science, Institute Technology Bandung, Indonesia. She is now the Head of Biavailability and Bioequivalence laboratory Faculty of Pharmacy, Universitas Indonesia. Prior to this position, she was the Dean of Faculty of Pharmacy, Universitas Indonesia. She has published more than 40 papers published in both International and National Journals. She has been an invited speaker in many international conferences, especially in the field of BA/BE and Bioanalysis technique. She currently serves as an expert at Indonesia National Agency of Drug and Food Control, spesifically in BA/BE evaluation.
Abstract:
The main challenge in conducting bioequivalence study, in this case bioanalytical method development, is the determination of analyte or metabolite in biological matrices primarily plasma, serum, and urine. It is performed due to the low drug level in biological matrices so that it requires sensitive, selective & accurate method. Development of bioanalytical method is a well-planned process in finding new method or modifying and improving the performance of on-going method, so that it is in accordance with its goal. After obtaining the optimum bioanalytical method, the next step is performing the validation method. The main objective of method validation is to demonstrate the reliability of a particular method for the determination of an analyte concentration in a specific biological matrices. The main characteristics of a bioanalytical method are essential to ensure the acceptability of the performance and the reliability of analytical results. The parameters are: selectivity, lower limit of quantification (sensitivity), accuracy, precision, carry over, linearity, matrix effects, stability of the analyte(s) in the biological matrices and stability of the analyte and internal standard in the stock solutions and in extracts under the entire period of storage and processing conditions. Once a valid method is acquired then it can be applied in bioequivalence study.
Keywords: Bioequivalence study; bioanalytical method validation; analyte, metabolite, biological matrices
Keynote Forum
Nasir Jalal
Tianjin University, China
Keynote: DNA strand break associated bystander effect (DSB-ABE) linked to gene mutations
Time : 11:15-12:15
Biography:
Nasir Jalal has completed his PhD from the Colorado State University, USA and currently engaged in postdoctoral studies at the School of Pharmaceutical Science and Technology, Tianjin University, China. He is an academician and researcher since 2007 working in the field of radiation induced DNA damage and repair mechanisms. He has published more than 10 papers in reputed journals and has served as the expert committee member for Biological drugs at the drug regulatory authority of Pakistan.
Abstract:
The goal of this project was to investigate whether radiation independent DNA damage, specifically a single induced DNA double strand break (DSB) can produce bystander signal, which is capable of inducing genomic instability in non-targeted cells. Previously uncharacterized E18 (modified TK6 cells) with a unique I-Sce1 insert in intron 2 of the thymidine kinase (TK1) gene were allowed to generate a bystander signal following electroporation of the rare cutting restriction enzyme I-Sce1 carried by a plasmid to induce DNA damage at the I-Sce1 site. Mutation assays were carried out to measure mutation fraction (MF) in directly targeted cells and using medium transfer, in non-targeted cells as a measure of bystander signal production. Transfection of the plasmid carrying I-Sce1 gene resulted in production of sufficient bystander signal into the medium to increase the bystander MF, when conditioned medium was applied from directly targeted to naïve E18 cells. The DSB-ABE exhibited temporal kinetics over a 10 hour duration. The relative direct and bystander MF increase due to the electroporation of three rare cutting restriction enzymes namely Not1 an 8 base cutter, Sfi1 a 13 base cutter (technically 8 because of the 5 non-specific bases in sequence) and I-Sce1 an 18 base cutter, showed that DSB-ABE does not show a dose-response. The bystander signal inhibition using superoxide dismutase (an enzyme that degrades reactive oxygen species) and PD 98059 (MEK1/2 inhibitor) indicated that the bystander signal activated the MAPK pathway in naïve cells. Higher levels of bystander mutation fraction were attempted through chemical inhibition of the three known enzymes of DNA repair (ATM, ATR and DNA PK) in directly targeted cells. Results reveal that inhibition of repair of I-Sce1 induced damage was not linked to bystander response. Further, sufficient bystander signal was produced by a presumably single I-Sce1 induced DNA break. The bystander signal produced, exhibited a dose-response in naïve cells and there was suggestion for the involvement of MAPK pathway.
- Drug Formulation Procedures | Novel Drug Delivery System | Traditional Medicine
Chair
Peng Li
University of California, Irvine USA
Session Introduction
Peng Li
University of California, Irvine USA
Title: Neurotransmitters related to the acupuncture inhibitory effect on hypertension
Biography:
Peng Li In 1950 graduated from Shanghai first Medical College (Shanghai Medical College of Fudan University), Worked in Department Physiology from 1955-1999. Chair of this Department for 10 years. 1983-84 went to University of Birmingham, UK to learn electrophysiology & have studied over 55 years about electro acupuncture (EA) effect on cardiovascular diseases. Now he worked in the School of Medicine at UC Irvine & has examined the underlying mechanisms of EA with several animal models. Licensed to perform acupuncture in California, investigate the effects of EA in hypertensive patients. He have published over 153 articles and organized five international symposiums.
Abstract:
All antihypertensive medications have adverse side effects. However, physicians are reluctant to recommend acupuncture, owing to its controversial reports in treating hypertension and the unclear physiological mechanisms. Recently, according to the results of our data over 60 years animal experiments we conducted a clinical trial and showed that EA at certain acupoints reduced high blood pressure in 70 % patients with mild to moderate hypertension, and the effect showed a slow onset and long-lasting. In animal experiments we demonstrated that EA inhibited cardiovascular sympathoexcitatory neurons through activation of neurons in the hypothalamic arcuate nucleus, the ventrolateral PAG (vlPAG) in the midbrain and the nuclei raphe in the medulla, which in turn, inhibited the activity of premotor sympathetic neurons in the rostral ventrolateral medullar (rVLM) to reduce blood pressure. The arcuate also projects to the rVLM and contains endorphin. The neurotransmitters glutamate, acetylcholine, opioids, GABA, nociceptin, serotonin and endocannabinoids all participate in the EA hypotensive response, their importance varies between nuclei. The long-lasting inhibition of EA is related to opioids and GABA in the rVLM, neural circuitry between the arcuate and vlPAG, and prolongation of the increase in preproenkephalin mRNA and enkephalin expression in the rVLM and arcuate. The inhibition of sympathetic activity, renin, angiotensin and aldosterone are quite important. Thus, a number of mechanisms underlying the EA effect on hypertension have been suggested.
Ling Chen
Shanghai East Hospital, China
Title: What do we understand from clinical and mechanistic studies on acupuncture treatment for hypertension?
Biography:
Dr.Ling CHENG is Vice Chief to the Department of Acupuncture in East Hospital at Shanghai Tong-Ji University. She is currently the Deputy Head of Acupuncture-Moxibustion Group, Medical Association of Pudong New District, Shanghai. Pioneer Talent of Traditional Chinese Medicine (TCM) Practitioners in Pudong New District, Shanghai.
Abstract:
Our clinical study show that low current and low frequency electroacupuncture at P5-6 (overlying median nerve) and S36-37 (overlying deep peroneal nerve) reduces high blood pressure in a subset of patients (~70%) with mild to moderate hypertension. The effect is slow in onset (4-8 weeks) but is long-lasting (1-2 months). Experimental studies have shown that EA inhibits cardiovascular sympathoexcitatory neurons through activation of neurons in the arcuate nucleus of the hypothalamus, ventrolateral periaqueductal gray (vlPAG) in the midbrain and nucleus raphe pallidus (NRP) in the medulla, which in turn, inhibits the activity of premotor sympathetic neurons in the rostral ventrolateral medulla (rVLM) to ultimately reduce blood pressure. Several neurotransmitters such as glutamate, acetylcholine, opioids, GABA, nociceptin, serotonin and endocannabinoids participate in the EA hypotensive response although their importance varies between nuclei. The long-lasting inhibition of EA is related to opioids and GABA in the rVLM, neural circuitry between the arcuate and vlPAG, and prolongation of the increase in preproenkephalin mRNA and enkephalin expression in the rVLM and arcuate. The inhibition of sympathetic activity, renin, angiotensin and aldosterone may be quite important. Thus, a number of mechanisms underlying the actions and long-lasting effect of EA on cardiovascular function have been identified, but clearly further investigation is warranted.
Biography:
Yahdiana harahap completed her PhD from Pharmacy Department, Faculty of Mathematics and Natural Science, Institute Technology Bandung, Indonesia. She is now the Head of Biavailability and Bioequivalence laboratory Faculty of Pharmacy, Universitas Indonesia. Prior to this position, she was the Dean of Faculty of Pharmacy, Universitas Indonesia. She has published more than 40 papers published in both International and National Journals. She has been an invited speaker in many international conferences, especially in the field of BA/BE and Bioanalysis technique. She currently serves as an expert at Indonesia National Agency of Drug and Food Control, spesifically in BA/BE evaluation.
Abstract:
Curcumin is a polyphenol, found in the spice turmeric from the rhizome of Curcuma Longa. After oral administration, curcumin undergoes rapid metabolism by conjugation and reduction. Curcumin levels are generally low so that the required bioanalytical method is selective and sensitive. A simple, specific and rapid UPLC-MS/MS method has been developed and validated for the estimation of curcumin in human plasma, using diazepam as internal standard (IS). The separation was done using UPLC BEH C18 column (1.7 µm, 2.1 x 100 mm) Acquity® Waters; 0.15% formic acid - acetonitrile (50:50, v/v) as mobile phase; flow rate of 0.5 mL/min; using liquid-liquid extraction with the mixture of ethyl acetate-methanol (95:5) for the sample preparation. The ionization mode was performed using electrospray ionization (ESI) detection in multiple reaction monitoring (MRM) in positive ionization mode. The monitored MS/MS ion transitions were m/z 369.05 >176.95 and 284.95 > 193 for curcumin and diazepam respectively. The method fulfilled the requirement of EMEA Bioanalytical Method Validation Guidelines 2011 and the calibration curve was linear in concentration range of 1 – 100 ng/mL, thus LLOQ for curcumin was 1 ng/mL. The method was applied to determine the level of curcumin in healthy subject after 1800 mg oral administration of curcumin dosage form. There was no free curcumin determined in plasma sample, but curcumin glucuronides and sulfates were detected in plasma subject. The ratio of glucuronide to sulfate was 4:1.
Nasir Jalal
Tianjin University, China
Title: DNA strand break associated bystander effect (DSB-ABE) linked to gene mutations
Biography:
Nasir Jalal has completed his PhD from the Colorado State University, USA and currently engaged in postdoctoral studies at the School of Pharmaceutical Science and Technology, Tianjin University, China. He is an academician and researcher since 2007 working in the field of radiation induced DNA damage and repair mechanisms. He has published more than 10 papers in reputed journals and has served as the expert committee member for Biological drugs at the drug regulatory authority of Pakistan.
Abstract:
The goal of this project was to investigate whether radiation independent DNA damage, specifically a single induced DNA double strand break (DSB) can produce bystander signal, which is capable of inducing genomic instability in non-targeted cells. Previously uncharacterized E18 (modified TK6 cells) with a unique I-Sce1 insert in intron 2 of the thymidine kinase (TK1) gene were allowed to generate a bystander signal following electroporation of the rare cutting restriction enzyme I-Sce1 carried by a plasmid to induce DNA damage at the I-Sce1 site. Mutation assays were carried out to measure mutation fraction (MF) in directly targeted cells and using medium transfer, in non-targeted cells as a measure of bystander signal production. Transfection of the plasmid carrying I-Sce1 gene resulted in production of sufficient bystander signal into the medium to increase the bystander MF, when conditioned medium was applied from directly targeted to naïve E18 cells. The DSB-ABE exhibited temporal kinetics over a 10 hour duration. The relative direct and bystander MF increase due to the electroporation of three rare cutting restriction enzymes namely Not1 an 8 base cutter, Sfi1 a 13 base cutter (technically 8 because of the 5 non-specific bases in sequence) and I-Sce1 an 18 base cutter, showed that DSB-ABE does not show a dose-response. The bystander signal inhibition using superoxide dismutase (an enzyme that degrades reactive oxygen species) and PD 98059 (MEK1/2 inhibitor) indicated that the bystander signal activated the MAPK pathway in naïve cells. Higher levels of bystander mutation fraction were attempted through chemical inhibition of the three known enzymes of DNA repair (ATM, ATR and DNA PK) in directly targeted cells. Results reveal that inhibition of repair of I-Sce1 induced damage was not linked to bystander response. Further, sufficient bystander signal was produced by a presumably single I-Sce1 induced DNA break. The bystander signal produced, exhibited a dose-response in naïve cells and there was suggestion for the involvement of MAPK pathway.
Sevgi Gungor
Istanbul University, Turkey
Title: Vesicular nanocarriers designed for the topical treatment of psoriasis
Biography:
Dr. Sevgi Güngör currently is an Associate Professor of Pharmaceutical Technology at Faculty of Pharmacy, Istanbul University. She is a lecturer at since 2004. She has also worked visiting scientist at University of Bath in between 2005-2006; 2007-2008. Dr. Güngör has published more than 30 papers in peer reviewed journals, 7 book chapters in international books. She has given more than 50 oral and poster presentations in international conferences. Her research focuses on the enhancement of skin permeation of drugs with enhancers, colloidal, vesicular, and micellar nanocarriers, and iontophoresis; the characterization of skin transport mechanism of drugs; and the development of innovative topical&transdermal systems.
Abstract:
Psoriasis is a chronic inflammatory skin disease with unknown etiology. It affects significantly the quality of life of patients as much as other chronic diseases such as cancer or diabetes. Psoriasis therapy varies depending on its severity but there is still a need of more effective and safe treatments. Topical treatment is considered as first option to treat psoriatic skin. It offers targeted delivery to the dermis and epidermis with reduction of systemic absorption and consequently minimizing side effects. However, the skin represents an effective barrier in localized skin delivery. Thus, the available conventional formulations of anti-psoriatic agents suffer from the poor penetration through the skin, resulting in low topical bioavailability. Nanocarriers are promising approach used largely in the last decades to improve the drawbacks combined with the conventional preparations. Thet provide control the release of therapeutic agents into skin with localized effect by creating skin reservoirs. Vesicular systems such as as liposomes, ultradeformable liposomes, ethosomes and transethosomes are developed as drug carrier systems to target lower layers of skin with new approaches based on modification of vesicle ingredients. These vesicular nanocarriers could enhance the deposition of drug into target sites of the skin layers, consequently topical bioavailability may also be increased and dosing frequency decreased. In this context, vesicular nanocarriers of selected lipophilic antipsoriatic drugs were developed to provide a targeted topical delivery for the treatment of psoriasis.
Biography:
Dr. S. Rajendran. M.Sc., M.Phil., Ph.D., is an Associate Professor at Saraswathi Narayanan College and a Coordinator of Unit of Rural Biotechnology at Saraswathi Narayanan College, INDIA. He has over 50 scientific papers & projects either presented or published. He is an internationally recognized expert in many areas of Environmental Biology including Solid Waste management, Waste water treatment, Anaerobic digestion, Biofuel, Bioenergy production and formulator of Bio-Pesticide and Herbicide and serving as a reviewer in many biological journals. He has delivered a key note speech in various international conferences and also given invited lectures in various educational institutions and universities. He has also chaired the scientific sessions in conferences. He is one of the leading scientific writers in Tamil Dailies. He has conducted more than 30 scientific workshops for the upliftment of rural people and women self help groups. He also had given training to municipalities employees about garbage disposal. His excellence in environmental science he was awarded with Patron of Environment by Tamil Nadu Government in 2006. He also is serving as a consultant in many of the environmental organizations. His research group is actively working in the following aspects: MSW management, Mushroom culture, Biofuel generation, Waste water treatment and Bio pesticide and herbicide development. His work in biological derustification is a novel pioneer technique and growing area in the environmental biotechnology.
Abstract:
Rust is the reddish brown oxide of iron formed by the action of moisture and oxygen on the metal. It is an electrochemical corrosion which weaking the iron structures. It was estimated that the corrosion alone causing a loss of over $5000bn USD to global economy every year. According to a recent report of NACE the corrosion cost in any developing countries predicated by 5% of the GDP, for India the cost of corrosion is estimated to be Rs1.52lakh crore per year. All available methods for rust removal and corrosion prevention are having their own limitations. Therefore, it is an urgent need to find out suitable method to check the corrosion. A fungal based biological derustification process was observed and reported by us already. This present investigation deals with our further experiments and experiences on the fungal based technology for iron rust removal. The derustification process was repeated once again to conform the reproducibility of the technology in polybag fermenters. Rusty iron mesh which were rolled in the form of cylinders were placed in the fermenters to expose them to the aerosol particles generated by the fungus. The rate of derustification was noted. Attempts were also made to enhance the aerosol generation from the substrate (straw) by coconut water supplementation. It was observed that the rusty metals placed in the supplemented substrate where derusted quickly then the raw substrate. Various level of supplementation was also correlated with rate of derustification. Further works on rust removal process are under progress.
- Formulation | Novel Drug Delivery System| Analytical Method Development and Validation | Medicinal Chemistry
Chair
Yahdiana Harahap
Universitas Indonesia, Indonesia
Session Introduction
Likun Wang
Jiangsu Hengrui Medical Co. Ltd, China
Title: Small molecule enabling formulation development: A super-saturation perspective
Biography:
Likun got his Bachelor’s degree in Biomedical Devices and PhD in Industry Pharmacy with focus on PAT, imaging, pelletization and coating process. Likun Joined Johnson & Johnson Pharmaceutical Research & Development (Belgium Site) in 2011 and act as scientist to develop and manage automated screening platforms for early development. In 2014, Likun became senior scientist and preformation group leader for automated screening and early development. In 2015, Likun joined Jiangsu Hengrui Medical co. as NanJing R&D site director and returned to China. Hengrui Nanjing R&D site is responsible for preformuation & early development for NMEs, formulation innovation for generics as well as external collaborations and innovation with Universities and research Institutes.
Abstract:
Over 90% of small molecule NMEs are poorly water soluble and supersaturation drug delivery systems, i.e. amorphous solid dispersions, Nanosuspensions and lipid based drug delivery systems, are the main strategy to enhance bioavailability. Supersaturation can also be included due to pH change during GI transition for both free form and pharmaceutical salt. Supersaturation can also increase flux rate by creating higher API concentration gradient in the GI tract. Therefore, it is critical to obtain a good understanding of the kinetics of supersaturation process both in-vitro and in-vivo. As supersturation can occur rapidly and it can be very sensitive to pH, hydrodynamics, a real-time concentration monitoring, multi-channel and miniaturized setup was used to investigate the kinetics of supersaturation. The results were also compared with HPLC analysis for validation purpose. The in-vitro data was also used to model and simulation supersaturation process by GastroPlus to further understand the impact of supersaturation on biopharmaceutics. Case studies of how supersaturation studies can help with formulation design to enhance bioavailability in different situations were given. Finally, the future direction of supersaturation investigations and applications was also shared.
Himankar Baishya
Beijing Sciecure Pharmaceuticals, China
Title: The influence of polyvinyl Pyrrolidone as hydrophilic pore formers on the release of water insoluble Ketoprofen from Ethyl cellulose coated pellets
Biography:
He has more than decade of experience in Generic Pharmaceutical Industry. He is having expertise on Drug product Development as well as Product Lifecycle management. He has started his career with Orchid Healthcare (Pfizer group companies) later he worked in Riyadh Pharma (Saudi Arabia), Kotra Pharma Sdn. Bhd (Malaysia), Yiling Pharmaceuticals, China & currently working in Beijing Sciecure Pharmaceuticals co. Ltd as Senior Director. He has many publications in International Journals & also Editor of Avens Journal on Cancer Science, USA.
Abstract:
Delivering water-insoluble drugs from Ethylcellulose (EC) coated pellets in a controlled-release pattern is very challenging. In the present study, hydrophilic polyvinylpyrrolidone (PVP) was used as a pore-former in EC coated pellets to deliver practically water-insoluble ketoprofen and the key factors that influenced drug release were identified. The effect of using PVP at different level in polymer coating part was studied and it was found that a certain level of PVP is required as channeling or pore forming agent to control drug release from the EC coated pellets to achieve target level of dissolution profile with the sensitivity ranging from 10% to 20%. PVP leaching rate and water permeability from EC/PVP film increased with the PVP level, which was perfectly correlated with drug release rate. PVP % was optimized with the application of Design of Experiments (DOE) and other process controls was evaluated during scale-up batches.
Rajesh Oswal
Rajmata Jijau Shikshan Prasarak Mandal's, India
Title: Formulation and evaluation of modified disintegrating sustained release tablets
Biography:
Dr. Rajesh Oswal has completed his PhD at the age of 27 years in 1998 from University of Pune (India). He is working as University Approved Full Time Professor and Principal, Ex-Member Board of Studies and Exam of SPPU University, Pune, Principal Research Investigator for NDDS & CDDS Reseach Projects, Research Guide of Postgraduate and Doctorate Research Work of University of Pune & many more Universities. He has published more than 60 papers in reputed journals and serving as an editorial board member of repute Journals.
Abstract:
Oral drug delivery is the largest and the oldest segment of the total drug delivery market. It is the fastest growing and most preferred route for drug administration. In oral drug delivery, the sustained release (SR) tablets maintains the desired drug concentration for prolong period of time, reduced 'see- saw' fluctuation, reduced total dose, improved efficiency in treatment. But many patients such as paediatric, geriatric and Dysphagia patients does not find it easy to take tablets and this is simply injustice with the prescription. Also the travelling patients require water for the swallowing the tablets. This problem is overcome by formulating and developing modified disintegrating sustained release tablets. In this case, first microspheres of the drug are formulated by using any suitable technique. And then optimized microspheres formulation is further formulated in to the fast disintegrating tablets (FDT) by using Superdisintegrants. So that after taking such tablets, the tablet only disintegrates into the mouth then microspheres are separated and ingestion of such microspheres starts releasing drug for prolonged period of time. Due to this concept it satisfies both objectives as sustained release action by using microspheres and the formulating such microspheres into fast disintegrating tablet overcoming the problem of swallowing and need of water. So it fulfils both the advantages of sustained release and fast disintegrating tablets.
Smrithi Khatri
Ram-Eesh Institute of Vocational and Technical Education, India
Title: Floating capsules of Acyclovir with Piperine as a bioenhancer
Biography:
Dr.Smriti Khatri had comlpleted her M.Pharm from S.G.S.I.T.S College Indore in 2003 and PhD from J.N.U, Jaipur in 2012. She is working as Associate Professor in Ram-Eesh Institute of Vocational and Technical Education, Greater Noida, U.P India. She is having teaching experience of more than 12 years. She has an expertise in the formulation of Dosage forms, Drug regulatory affairs and intellectual property rights. She has published more than 25 papers in international and national journals.
Abstract:
The aim of the present study was to formulate and characterize the capsules of acyclovir microspheres with piperine which were prepared by emulsification solvent evaporation method. Piperine was added to determine its effect on acyclovir bioavailability. The microspheres were characterized for size, shape, entrapment efficiency, in vitro drug release, and in vivo pharmacokinetic parameters. The morphological characterization of microspheres was done using a scanning electron microscope. The microspheres were spherical and had particle size in the range of 400 to 525 μm. The percent drug entrapment efficiency varied between 56.12 ± 1.32 % to 87.32 ± 5.28 %. The drug release was decreased at higher polymer concentrations. Based on invitro results, further invivo studies were carried out on Sprague Dawley strain rats to evaluate the bioavailability of acyclovir. Nearly two times higher AUC0–24 value of acyclovir-loaded piperine containing microspheres (15614.13 ± 6953.13 ng h ml−1) was observed as compared to the drug solution (7552.33 ± 3219.09 ng h ml−1).
Azar Tahghighi
Pasteur Institute of Iran, Iran
Title: Importance of 5-(5-nitrohetroaryl-2-y1)-1,3,4-thiadiazole scaffolds for development of potential Leishmanicidal agents
Biography:
Azar Tahghighi has completed her PhD from Tabriz University of Medical Science of Iran. She is a medicinal chemist, assistant professor and a member of research team focusing on drug and insecticide discovery at MVRG in Pasteur Institute of Iran. She has published more than 15 papers in reputed journals and serving as a reviewer for some journals.
Abstract:
Parasitic diseases are a major problem in tropical and subtropical regions of the world such as malaria and leishmaniasis. These diseases are the cause of considerable mortality and morbidity annually. No vaccines to prevent infections are available. In the other hand, parasitic drug resistances have restricted the use of available drugs for treatment of malaria and leishmaniasis. Actually, Identification and development of new, cheap, efficient, and safe compounds as drug candidates for the treatment of these diseases are imperative from pharmaceutical point of view. Therefore, a range of creative strategies are required to achieve new lead compounds. The aims of our studies were to synthesis and assess antiparasitic property of 5-(5-nitrohetero aryl-2-yl)-1,3,4-thiadiazoles with different substituents at the 2-position of thiadiazole ring. It was notable that the bioresponses and physicochemical properties of the molecules depended on the type of these substituents. In these studies, MLR and ANN models were used for the prediction of the antileishmanial activity of some thiadiazole derivatives. Both of them were successful in predicting the antileishmal activity. Also, molecular modeling and docking studies were conducted based on DNA topoisomerase I as a target enzyme. The results suggested that hydrogen bonding and hydrophobic interactions of ligands with the active site of Leishmania major topoisomerase IB were responsible for their potent antileishmanial activity. Therefore, these results can be used for drug design and development of new and selective leishmania topoisomerase inhibitors.
Ibrahim Abdurrahman Adam
Northwest Normal University, China.
Title: Isolation and structural elucidation of chemical constituents, from stem bark of Xeromphis nilotica ( Rubiaceae)
Biography:
Adam Ibrahim obtained his MSc in applied Chemistry in 2011 from Hassan II University, Morocco. Now he is PhD student at College of chemistry and chemical engineering, Northwest Normal University, Lanzhou, China. He has more than 12 years of teaching experience at University of Zalingei, Sudan. He has published three papers in international journals of repute.
Abstract:
In Africa and in many developing countries, medicinal plants are used in the treatment of various diseases and a large number of people depend on medicinal plants because they have no access to modern medicines. Xeromphis nilotica has been reported to posses bone fracture healing, antibacterial, antioxidant, anti-convulsant, anti-nociceptive and anti-inflammatory activities. Many active compounds have been reported from this plant including coumarins, alkaloids, flavonoids, terpenes saponins, Iridoids and other compounds. In the present work, on the bases of chromatographic and spectroscopic [ 1D, 2D-NMR and HR-ESI-MS ] and chemicals methods, beside four known compounds Lupeol 1, 3β-hydroxyolean-12-en-28-oic acid 2, Stigmasterol 3 and daucosterol 4, we isolated and structural elucidated new triterpenoid Saponin,3-O-{O-α-L-rhamno-pyranosyl-(1→3)-O-[-O-β-D-glucopyranosyl-(1→3)]-β-D glucopyranosyl}-Oleanolic acid 5, from stem bark of Xeromphis Nilotica.