Hypoglycaemic Effect of Alkaloids Preparation From Leaves of Aegle Marmelose

Alloxan induced diabetic animal model was used to evaluate the antidiabetic effect of alkaloids extracted from the leaves of Aegis marine/ose. The alkaloid extract maintained the weight of animals near to that of control ones - whereas there was a decrease in the body weight of diabetic animals. A significant increase in blood glucose (342. 14 -+- 14.89 mg/dl) was seen in diabetic animals but in alkaloid treated group the blood glucose was lowered (90: 12 +_5.81 mg/dl). There was no decrease in blood urea arid sreum cholesterol in the alkaloid treated group of diabetic animals. The liver glycogen decreased in diabetic animals (1.27+.12 g/100g of wet tissue) and the treatment brought the glycogen level to that of control ones (2.51 +.75 g/100 g of wet tissue). The result show that the alkaloid extract has hypoglycaemic activity.

Studies in the microbial tranformation of alkaloids strychnine and 2-nitrostrychnine

Strychnine is the major alkaloid present in the seeds of _Strychnos, nuxvomica tree which grow naturally in this area. Strychnine has a very complex chemical structure and is known to stimulate all portions of the central nervous system with preference to the spinal cord. However, it is a powerful convulsant and death results from asphyxia. Consequently strychnine has no therapeutic application in the western system of medicine at present. The objective of this work, therefore, was to convert strychnine by microbial transformation into a product having more desirable pharmacological properties so that this locally available natural product may find some use in the preparation of a therapeutic agent.

Brain 5HT2A Receptor Regulation by Tryptophan Supplementation in Streptozotocin Diabetic Rats

5-HT2A receptor binding parameters were studied in the cerebral cortex and brain stem of control, diabetic, insulin, insulin + tryptophan and tr3yptophan treated streptozotocin diabetic rats. Scatchard analysis using selective antagonist, [-H](±)2,3-dimethoxyphenyl-l-[2-(4-piperidine)- methanol] ([3H]MDL100907) in cerebral cortex of diabetic rats showed a significant decrease in dissociation constant (Kd) without any change in maximal binding (Bm). Competition binding studies in cerebral cortex using ketanserin against [3H]MDL100907 showed the appearance of an additional site in the low affinity region during diabetes. In the brain stem, Scatchard analysis showed a significant increase in Bmax and Kd. Displacement studies showed a shift in the receptor affinity towards a low affinity state. All these altered parameters in diabetes were reversed to control level by insulin, insulin + tryptophan and tryptophan treatments. Tryptophan treatment is suggested to reverse the altered 5-HT2Abinding and blood glucose level to control status by increasing the brain 5-HT content.

Enhancement of [m-methoxy 3H]MDL100907 binding to 5HT 2A receptors in cerebral cortex and brain stem of streptozotocin induced diabetic rats

5-Hydroxytryptamine2A (5-HT2A) receptor kinetics was studied in cerebral cortex and brain stem of streptozotocin (STZ) induced diabetic rats. Scatchard analysis with [3H] (±) 2,3dimethoxyphenyl-l-[2-(4-piperidine)-methanol] ([3H]MDL100907) in cerebral cortex showed no significant change in maximal binding (Bmax) in diabetic rats compared to controls. Dissociation constant (K) of diabetic rats showed a significant decrease (p < 0.05) in cerebral cortex, which was reversed to normal by insulin treatment. Competition studies of [3H]MDL100907 binding in cerebral cortex with ketanserin showed the appearance of an additional low affinity site for 5-HT2A receptors in diabetic state, which was reversed to control pattern by insulin treatment. In brain stem, scatchard analysis showed a significant increase (p < 0.05) in Bmax accompanied by a significant increase (p < 0.05) in Kd. Competition analysis in brain stem also showed a shift in affinity towards a low affinity State for 5-HT2A receptors. All these parameters were reversed to control level by insulin treatment. These results show that in cerebral cortex there is an increase in affinity of 5-HT2A receptors without any change in its number and in the case of brain stem there is an increase in number of 5HT2A receptors accompanied by a decrease in its affinity during diabetes. Thus, from the results we suggest that the increase in affinity of 5-HT2A receptors in cerebral cortex and upregulation of 5-HT2A receptors in brain stem may lead to altered neuronal function in diabetes.

In vivo screening of mangrove plants for anti WSSV activity in Penaeus monodon, and evaluation of Ceriops tagal as a potential source of antiviral molecules

The objective of the study was to find out a natural way to fight white spot syndrome virus (WSSV) in cultured shrimps, as the present scenario necessitated an organic remedy for the devastating pathogen in crustaceans. Under this research programme seven mangrove plants were collected, identified and aqueous extracts screened for their protective effect on the giant tiger shrimp Penaeus monodon against WSSV. The experimental design consisted two modes of application, such as exposure of the virus to the extract and injection challenge, and oral administration of the extract coated feed followed by oral challenge. All experimental animals were monitored through a nested diagnostic PCR analysis. Of the seven mangrove extracts screened aqueous extract from Ceriops tagal imparted total protection to shrimp from WSSV when challenged by both methods. Shrimps administered with the aqueous extract from C. tagal were devoid of virions. The HPLC fingerprint of the aqueous extracts from C. tagal showed more than 25 peaks and 7 of them were larger and well separated. Preliminary phytochemical analysis revealed the presence of alkaloids, flavonoids, polyphenolics, cardiac glycosides, saponins and sterols. The study indicated suitability of the aqueous extract of C. tagal as a possible prophylaxis for WSSV infection in shrimp. This is the first report on the anti WSSV property of the mangrove plant C. tagal

An Efficient Multi-component Synthesis of 6-Amino-3-methyl-4-Aryl-2,4- dihydropyrano[2,3-c]Pyrazole-5-carbonitriles

Multi-component reactions are effective in building complex molecules in a single step in a minimum amount of time and with facile isolation procedures; they have high economy1–7 and thus have become a powerful synthetic strategy in recent years.8–10 The multicomponent protocols are even more attractive when carried out in aqueous medium. Water offers several benefits, including control over exothermicity, and the isolation of products can be carried out by single phase separation technique. Pyranopyrazoles are a biologically important class of heterocyclic compounds and in particular dihydropyrano[2,3-c]pyrazoles play an essential role in promoting biological activity and represent an interesting template in medicinal chemistry. Heterocyclic compounds bearing the 4-H pyran unit have received much attention in recent years as they constitute important precursors for promising drugs.11–13 Pyrano[2,3-c]pyrazoles exhibit analgesic,14 anti-cancer,15 anti-microbial and anti-inflammatory16 activity. Furthermore dihydropyrano[2,3-c]pyrazoles show molluscidal activity17,18 and are used in a screening kit for Chk 1 kinase inhibitor activity.19,20 They also find applications as pharmaceutical ingredients and bio-degradable agrochemicals.21–29 Junek and Aigner30 first reported the synthesis of pyrano[2,3-c]pyrazole derivatives from 3-methyl-1-phenylpyrazolin-5-one and tetracyanoethylene in the presence of triethylamine. Subsequently, a number of synthetic approaches such as the use of triethylamine,31 piperazine,32 piperidine,33 N-methylmorpholine in ethanol,34 microwave irradiation,35,36 solvent-free conditions,37–39 cyclodextrins (CDs),40 different bases in water,41 γ -alumina,42 and l-proline43 have been reported for the synthesis of 6-amino-4-alkyl/aryl-3-methyl- 2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles. Recently, tetraethylammonium bromide (TEABr) has emerged as mild, water-tolerant, eco-friendly and inexpensive catalyst. To the best of our knowledge, quaternary ammonium salts, more specifically TEABr, have notbeen used as catalysts for the synthesis of pyrano[2,3-c]pyrazoles, and we decided to investigate the application of TEABr as a catalyst for the synthesis of a series of pyrazole-fused pyran derivatives via multi-component reactions

In vivo screening of mangrove plants for anti WSSV activity in Penaeus monodon, and evaluation of Ceriops tagal as a potential source of antiviral molecules

The objective of the study was to find out a natural way to fight white spot syndrome virus (WSSV) in cultured shrimps, as the present scenario necessitated an organic remedy for the devastating pathogen in crustaceans. Under this research programme seven mangrove plants were collected, identified and aqueous extracts screened for their protective effect on the giant tiger shrimp Penaeus monodon against WSSV. The experimental design consisted two modes of application, such as exposure of the virus to the extract and injection challenge, and oral administration of the extract coated feed followed by oral challenge. All experimental animals were monitored through a nested diagnostic PCR analysis. Of the seven mangrove extracts screened aqueous extract from Ceriops tagal imparted total protection to shrimp from WSSV when challenged by both methods. Shrimps administered with the aqueous extract from C. tagal were devoid of virions. The HPLC fingerprint of the aqueous extracts from C. tagal showed more than 25 peaks and 7 of them were larger and well separated. Preliminary phytochemical analysis revealed the presence of alkaloids, flavonoids, polyphenolics, cardiac glycosides, saponins and sterols. The study indicated suitability of the aqueous extract of C. tagal as a possible prophylaxis for WSSV infection in shrimp. This is the first report on the anti WSSV property of the mangrove plant C. tagal