Pb(II) sensor based on the membrane of 3,4,4a,5-tetrahydro-3-methylpyrimido[ l,6-a] benzimidazole-l (2H) thione in PVC matrix

819-8233,4,4a,5-Tetrahydro-3-methylpyrimido [1 ,6-a] benzimidazole- l (2H) thione (TMPB) has been synthesized and investigated as electroactive phase of membranes for use as Pb2+ selective electrode. PVC based membranes of TMPB have been prepared without plasticizer and with a number of plasticizers and investigated. Of the various plasticizers used, tris (2-ethylhexyl)phosphate (TEP) has been found to improve the performance of the membrane significantl y. The membrane having the composition of TMPB:PVC:TEP as 1:40:10 has been found to perform best . The electrode having such a membrane responds linearly to Pb2+ over a wide concentration range, 1.9×10-5- 1.0×10-1 M, with a slope of 28.5 mV/decade of concentration and small response time of 20 s. The electrode can work over a pH range of 2 to 5.7 and also in partially non-aqueous media. Selectivity coefficient values revealed that the electrode is sufficiently selective over a large number of mono, bi- and trivalent metal cations. It is found to have a life time of one month and could also be used as indicator electrode in the potentiometric titration of Pb2+ with EDTA

Synthesis and anticancer activity evaluation of some hemin and hematoporphyrin derivatives

388-393Sulphamerazine, sulphadiazine, and sulphaguanidine are coupled with hemin to give bis coupled products 1a, 1b and 1c respectively. 3, 4-Diphenyliminothiazoline, sulphamerazine, sulphaacetamide, sulphathiazole and sulphadiazine on coupling with hematoporphyrin give bis coupled products 2a, 2b, 2c, 2d and 2e respectively. Compounds 1a-c and 2a-e have been screened for anticancer activity against a small panel of six cancer cell lines consisting of prostate(DU 145), colon (HT29), melanoma (LOX), breast(MCF7 and MCF7/ADR) and CNS(U251) tumors. Best GI50 (concentration which inhibits the cell growth by 50%) values are shown by 2c, 2.2μM(prostate tumor, cell line DU145); 2c 13.0μM(colon tumor, cell line HT29); 2b, 3.4μM(melanoma tumor, cell line LOX); 2c, 9.7μM(breast tumor, cell line MCF7); 2a, 3.1μM(breast, tumor, cell line MCF7/ADR) and 1c, 3.4μM(CNS tumor, cell line U251) respectively. Out of all the compounds reported here GI50 value shown by 2a i.e.3.1μM against breast, tumor (MCF7/ADR) is quite close to the GI50 value i.e. 1.8μM, of standard drug doxorubicin

Synthesis, hydrolysis over silica column, anticancer, anti-inflammatory and analgesic activity evaluation of some pyridine and pyrazine derivatives

387-399Various 3,4-diaryl-2-iminothiazolines 1a-s have been condensed with 4-cyanopyridine and 2-cyanopyrazine by refluxing in methanol for about 16 hr to give corresponding 3,4-diaryl-2-imino-N-(4'-pyridyliminomethyl)-4-thiazoline (2a-k, n-p) and 3, 4-diaryl-2-imino-N-(2'-pyrazinyliminomethyl)-4-thiazoline (3a-m, q-s) derivatives. In some cases when these pyridyl and pyrazinyl derivatives are purified by column chromatography over silica gel these compounds get hydrolysed to give corresponding 3,4-diaryl-2-imino-N-(4'-carbonylpyridyl)-4-thiazoline (2o,p) and 3,4-diaryl-2-imino-N-(2'-carbonylpyrazinyl)-4-thiazoline (3q-s) derivatives. The structures of all synthesized compounds have been confirmed by spectroscopic methods. Compounds 2a-c,e-h,k,n,p, 3a-i and 3l,m,q are screened for anticancer activity against a small panel of six human cancer cell lines consisting of prostate (DU 145) colon (HT 29) breast (MCF 7) breast (MCF 7/ADR), CNS (U 251) and lung large (NCIH 460) tumors. Best GI50 values are shown by 3f, 11.5 M (prostate tumor, cell line DU 145), 3f, 1.0 M (colon tumor, cell line HT 29), 2n, 6.2M (breast tumor, cell line MCF 7), 2p, 4.8M (breast tumor, cell line MCF 7/ADR), 2p, 6.3M (CNS tumor, cell line U 251) and 3f, 0.9 M (lung large carcinoma, cell line NCIH 460) respectively. Compound 3f has shown good anticancer activity against three cancer cell lines, whereas compounds 2n and 2p against one and two cancer cell lines respectively. Antiinflammatory activity evaluation of 2a-k,n,o,p, 3a-m and 3q,r,s has been carried out and compounds 2a-h, 2j, 2o,p, 3a,b,c,g,m and 3r showed 13, 32.5, 48.8, 6.5, 13.9, 7.0, 4.3, 16.6, 20.0, 17.3, 27.7, 16.2, 18.4, 34.7, 15.6, 24.0 and 4.7% activity, respectively, at 100mg/kg p.o. Analgesic activity, evaluation of 2a-k,n,o,p, 3a-m and 3q,r,s indicates that these compounds possess 50, 25,75, 25, 50, 75, 50, 50, 25, 0.0, 50, 50, 0.0, 75, 50, 25, 25, 25, 75, 0.0, 25, 25, 25, 50, 50, 75, 25, 50, 75 and 50% analgesic activity at 100mg/kg p.o