مجال التميز | تميز دراسي وبحثي |
البحوث المنشورة |
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البحث (1): | |
عنوان البحث: |
Induction of Cryptic Antifungal Pulicatin Derivatives from Pantoea Agglomerans by Microbial Co-Culture |
رابط إلى البحث: | |
تاريخ النشر: |
10/02/2020 |
موجز عن البحث: |
Microbial co-culture or mixed fermentation proved to be an efficient strategy to expand chemical diversity by the induction of cryptic biosynthetic pathways, and in many cases led to the production of new antimicrobial agents. In the current study, we report a rare example of the induction of silent/cryptic bacterial biosynthetic pathway by the co-culture of Durum wheat plant roots-associated bacterium Pantoea aggolomerans and date palm leaves-derived fungus Penicillium citrinum. The initial co-culture indicated a clear fungal growth inhibition which was confirmed by the promising antifungal activity of the co-culture total extract against Pc. LC-HRMS chemical profiling demonstrated a huge suppression in the production of secondary metabolites (SMs) of axenic cultures of both species with the emergence of new metabolites which were dereplicated as a series of siderophores. Large-scale co-culture fermentation led to the isolation of two new pulicatin derivatives together with six known metabolites which were characterised using HRESIMS and NMR analyses. During the in vitro antimicrobial evaluation of the isolated compounds, pulicatin H (2) exhibited the strongest antifungal activity against Pc, followed by aeruginaldehyde (1) and pulicatin F (4), hence explaining the initial growth suppression of Pc in the co-culture environment. |
البحث (2): | |
عنوان البحث: |
Sesbania grandiflora L. Poir leaves: A dietary supplement to alleviate type 2 diabetes through metabolic enzymes inhibition |
رابط إلى البحث: | |
تاريخ النشر: |
25/01/2020 |
موجز عن البحث: |
Sesbania grandiflora L. Poir is an edible medicinal plant widely distributed in Asian countries. One of its folk medicinal uses is the alleviation or treatment of Type 2 Diabetes mellitus (T2DM). A number of animal studies confirmed its use in treating T2DM; however, none of them explored the chemistry or the possible mechanism. This study aims to unveil the chemical profile of S. grandiflora through LC-HRMS dereplication analysis, followed by isolation, identification and quantification of the major secondary metabolites with potential α-amylase and α glucosidase inhibitory effect as the potential anti-diabetic mechanism. LC-HRMS chemical profiling of its leaves and twigs identified 32 metabolites. Bio-guided fractionation and HPLC purification led to the isolation of 14 major metabolites that were screened for their α-amylase and α-glucosidase inhibitory activities. For the first time, two terpenoids; vomifoliol (11) and loliolide (14) showed inhibitory effect against α-glucosidase with IC50 values of 64.5 and 388.48 µM, respectively. Quercetin (10) exhibited the highest α-glucosidase inhibition with IC50 value of 17.45 µM. Further, predicated molecular modelling studies demonstrated strong binding interactions between active compounds and enzyme-substrate binding pockets supporting the observed enzyme inhibitory activity. Interestingly, the quantitative analysis of the most potent inhibitors indicated their existence at a high percentage within S. grandiflora extract. Our findings suggested S. grandiflora is a useful dietary supplement to control postprandial blood glucose. |
المؤتمرات العلمية |
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المؤتمر (1): | |
عنوان المؤتمر: |
38th Annual Conference on Advances in Cancer Research and Therapy |
تاريخ الانعقاد: |
11-12/11/2019 |
مكان الانعقاد: |
Madrid, Spain |
طبيعة المشاركة: |
Poster presentation |
عنوان المشاركة: |
Bioactive phenolic glycosides from the aerial parts of Stipagrostis plumosa (L.) Munro ex T.Anderson family Poaceae |
ملخص المشاركة: |
Cancer is a leading cause of death worldwide. Drug resistivity is a major drawback in the chemotherapeutic treatment. Thus the requirement for new drugs is a continuing requirement. The chemical extracts from Stipagrostis plumose are rich in phenolic glycosides and have proven bioactivities for many life threading diseases. In the current study, different natural isolated compounds were tested for their anticancer activity. |
المؤتمر (2): | |
عنوان المؤتمر: |
30th International Symposium on the Chemistry of Natural Products (ISCNP30 & ICOB10) |
تاريخ الانعقاد: |
25-29/11/2018 |
مكان الانعقاد: |
Athens, Greece |
طبيعة المشاركة: |
Poster presentation |
عنوان المشاركة: |
In vitro antitumour evaluation of different extracts of medicinal plants |
ملخص المشاركة: |
Cancer is a leading cause of death worldwide. According to WHO reports, more than 8.8 million deaths were recorded in 2015. Chemotherapeutic drug resistance has threatened the achievements of modern medicine. The extracts of from plant sources are rich in phytochemicals and they have proven to provede promising bioactivities. Hence the search for new natural inhibitors is paramount I the quest to find broader range and novel products for the treatment of cancers with minimal side effects. In the current study, Arctostaphylos uva-ursi (leaves), Commiphora myrrha (resin), Nigella sativa (seeds), Peganum harmala (leaves) and Saussurea costus (roots) were collected from Saudi Arabian. The dried plant samples were macerated and extracted into methanol. The resulting crude extracts were tested for their anti-proliferative activity against NCI H295R (adrenal gland) and HeLa (cervix) cancer cell lines using MTT assay. The total crude extracts of all the tested samples showed more than 80% cytotoxic activity while, A. uva-ursi showed 50% cytotoxic activity at 50 g/mL concentration. Further, total methanol crude extracts were fractionated sequentially into hexane, dichloromethane and ethyl acetate. The resulting fractions were tested for cytotoxic activity. All the fractions of the C. myrrha and N. sativa showed good cytotoxic activity for both cervix and adrenal gland cell lines. Only the hexane fraction of A. uva-ursi showed good cytotoxic activity for both cell lines, while dichloromethane fraction was moderately active for cervix HeLa cell line only. Both the hexane and dichloromethane fractions of P. harmala and S. costus showed good cytotoxic activity for both cell lines. To identify the phytochemicals present in the active extracts of these plants, chemical profiling using GCMS and LC-HRESIMS are underway. |
ماجد محمد عبدالرحيم باوزير
دكتوراه
الطب والخدمات الصحية
University of the West of Scotland