Browsing by Author "Majik, M.S."
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2D NMR Studies of Bromotyrosine Alkaloid, Purpurealidin K from Marine Sponge Psammaplysilla purpurea
Tilvi, S.; Majik, M.S. (2019)Marine sponges of the order Verongida and related organisms are the richest source of bioactive bromotyrosine alkaloids. Purpurealidin K (1) along with purealidin Q (2), aerophobin 2 (3) and aplysamine 2 (4) were isolated ... -
A concise synthesis of (R)-Bgugaine, a pyrrolidine alkaloid from Arisarum vulgare
Majik, M.S.; Parameswaran, P.S.; Tilve, S.G. (Science Reviews 2000 Ltd, 2008)A new short method for the preparation of (R)-Bgugaine (1) has been described using Wittig condensation of a nonstabilised ylide with N-carboethoxy prolinal followed by reduction of double bond and conversion of N-carboethoxy ... -
A short synthesis-stuttgart of (S)-pyrrolam A via domino oxidation-witting reaction
Majik, M.S.; Shet, J.; Tilve, S.G.; Parameswaran, P.S. (Thieme, 2007)A short synthesis of (S)-pyrrolam A starting from readily available N-(benzyloxycarbonyl)-L prolinol is described that makes use of a domino primary alcohol oxidation-Witting reaction as the key step -
Bioactive alkaloids from marine sponges
Singh, K.S.; Majik, M.S. (2016)Marine sponges are considered to be a rich source of biologically active secondary metabolites with unique and diverse chemical structures. They constitute nearly one third of the secondary metabolites isolated from marine ... -
Bis(indolyl)methane alkaloids: Isolation, bioactivity, and syntheses
Praveen, P.; Parameswaran, P.S.; Majik, M.S. (Georg Thieme Verlag Stuttgart, 2015)Bis(indolyl)methane (BIM) alkaloids are an important group of bioactive natural products predominantly found in marine organisms. Thus, compounds like arsindoline A and B, vibrindole A, arundine, and trisindoline are found ... -
Construction and screening of 2-aryl benzimidazole library identifies a new antifouling and antifungal agent.
Majik, M.S.; Tilvi, S.; Mascarenhas, S.; Kumar, Vikash; Chatterjee, Amrita; Banerjee, Mainak. (RSC, 2014)Biofouling is the undesirable growth of organisms on artificial and natural structures immersed in either seawater or freshwater. It causes huge economic loss and also the global prohibition on known antifouling agents has ... -
Design and synthesis of marine natural product-based 1H-indole-2,3-dione scaffold as a new antifouling/antibacterial agent against fouling bacteria.
Majik, M.S.; Rodrigues, C.; Mascarenhas, S.; DeSouza, L. (Elsevier, 2014)Marine organisms such as seaweeds, sponges and corals protect their own surfaces from fouling by their high anesthetic, repellant, and settlement inhibition properties. Within the marine ecosystem, evolution has allowed ... -
Evaluation of single and joint effect of metabolites isolated from marine sponges, Fasciospongia cavernosa and Axinella donnani on antimicrobial properties.
Majik, M.S.; Shirodkar, D.; Rodrigues, C.; DeSouza, L.; Tilvi, S. (Elsevier, 2014)The biochemical mechanisms that marine sponges have developed as a chemical defense to protect themselves against micro and subsequent macrobiofouling process might comprise a potential alternative for the preventing attack ... -
Intramolecular Wittig reaction: A new synthesis of (S)- pyrrolam A
Majik, M.S.; Parameswaran, P.S.; Tilve, S.G. (Verlag Helvetica Chimica Acta AG, 2008)A straightforward synthesis of (S)-pyrrolam A is described. The synthesis involves in situ generation of the phosphorane 3, followed by an intramolecular Wittig reaction to furnish (S)-pyrrolam A -
Isolation and Identification of Tyrosinase Inhibitors from Marine Algae Enteromorpha sp
Rodrigues, L.; Tilvi, S.; Fernandes, M.S.; Harmalkar, S.S.; Tilvi, S.; Majik, M.S. (Bentham Science Publishers, 2021)The extract of marine green algae Enteromorpha sp. was evaluated in vitro for inhibitory activity against mushroom tyrosinase enzyme. The principle active agents i.e. coumarin; 4-hydroxycoumarin (1) and two sterols; ... -
Isolation of stigmast-5,24-dien-3-ol from marine brown algae Sargassum tenerrimum and its antipredatory activity
Majik, M.S.; Adel, H.; Shirodkar, D.; Tilvi, S.; Furtado, J. (Royal Society of Chemistry, 2015)In recent years many sterols with potent biological activity have been identified from marine sources. Here we report the isolation of stigmast-5,24-dien-3-ol (fucosterol) as a major metabolite from the bioactive hexane-fraction ... -
Marine-derived fungi: Source of biologically potent and novel compounds
Majik, M.S.; Parvatkar, R.R.; Tilvi, S.; Gawas, S.G. (Elsevier, 2016) -
Marine-Derived Natural Products Inhibiting Specific Inflammatory Cytokines
Tilvi, S.; Parvatkar, R.R.; Majik, M.S. (Elsevier, 2019)Inflammation is one of the earliest innate immune responses to tissue injury and various pathological stimuli. It is characterized by the recruitment and accumulation of immune cells in injured sites and by the production ... -
Mass spectrometry for determination of bioactive compounds
Tilvi, S.; Majik, M.S.; Singh, K.S. (Elsevier, 2014)Mass spectrometry (MS) has emerged as an invaluable technique with a wide array of applications ranging from forensic, proteomic, metabolomic to clinical studies. With the development of different ionization techniques and ... -
Microwave-assisted reductive cyclization: An easy entry to the indoloquinolines and spiro[2H-indole-2,30-oxindole].
Parvatkar, P.T.; Majik, M.S. (Royal Society of Chemistry, 2014)Synthesis of two linear indoloquinolines i.e. 6H-indolo[2,3-b]quinoline & 11-hydroxy-10H-indolo[3,2-b]quinoline, and spiro[2H-indole-2,3'-oxindole] from a common intermediate, (2-nitrophenyl)methylidene-dihydro-indolone ... -
Next Generation Biofilm Inhibitors for Pseudomonas aeruginosa: Synthesis and Rational Design Approaches
Majik, M.S.; Parvatkar, P.T. (Bentham Science, 2014)The bacterial biofilms and the emergence of multiple drug resistance have become a major threat for current medical treatment of nosocomial infections. It has been estimated that about 65-80% of microbial infections in the ... -
Pyrrole-Derived Alkaloids of Marine Sponges and Their Biological Properties
Singh, K.S.; Majik, M.S. (Elsevier, 2019)Marine sponges remain an unambiguously significant source of secondary metabolites from marine invertebrates. It is estimated that more than 15,000 compounds have been discovered from marine sources, and new compounds are ... -
Pyrrolizidine alkaloids pyrrolams A-D: A survey of synthetic efforts, biological activity, and studies on their stability
Majik, M.S.; Tilve, S.G. (Georg Thieme Verlag KG, 2012)Pyrrolam A is a microbial metabolite, structurally related to plant alkaloids of the necine-type, and was isolated from the bacterial strain of Streptomyces olivaceus along with the related alkaloids pyrrolams B-D. The ... -
Quick elucidation of cyclodepsipeptide sequence from sacoglossan Elysia grandifolia using electrospray ionisation-tandem mass spectrometry
Tilvi, S.; PrabhaDevi; Majik, M.S. (Sage Publications, 2017)Butanol fraction of sacoglossan Elysia grandifolia was investigated for identifying peptides using electrospray ionisation-tandem mass spectrometry (ESI-MS/MS). Without prior isolation, the structural determination is ... -
Recent developments towards the synthesis of Varitriol: An antitumour agent from marine derived fungus Emericella variecolor.
Majik, M.S.; Tilvi, S.; Parvatkar, P.T. (Bentham Science Publishers, 2014)Marine natural products are recognized as a fruitful source of drug development due to their rare structural entities and diverse biological activities, and consequently, publicized number of metabolites as new medicines. ...