Thiamin (vitamin B1) is an essential micronutrient needed as a cofactor for many central metabolic enzymes. Animals must have thiamin in their diet, whereas bacteria, fungi, and plants can biosynthesize it de novo from the condensation of a thiazole and a pyrimidine moiety. Although the routes to biosynthesize these two heterocycles are not conserved in different organisms, in all cases exogeno...

We confirmed multiple picoeukaryotic algae, Ostreococcus, Micromonas, and Pelagomonas spp., as thiamine (vitamin B1) auxotrophs in laboratory experiments with axenic cultures. Examined strains have half saturation growth constants (Ks) for B1 between 1.26 and 6.22 pmol B1 L , which is higher than reported seawater concentrations. Minimum B1 cell quotas for Ostreococcus and Micromonas spp. are h...

Thromboxane A2 Biosynthesis in the Ureter Obstructed Isolated Perfused Kidney ofthe Rabbit. AUBREY R. MORRISON, KOHEI NISHIKAWA AND PHILIP NEEDLEMAN 1 Kinetic Analysis of the Renal Handling of 2,2,Bis(p-Chlorophenyl) Acetic Acid by the Rat. JOHN B. PRITCHARD 9 Studies with a New Antifolate 2,4-Diamino-5-Adamantyl-6-Methylpynimidine (DAMP): Tissue Distnbution and Disposition of 2,4-Diamino-5-Ada...

Thromboxane A2 Biosynthesis in the Ureter Obstructed Isolated Perfused Kidney ofthe Rabbit. AUBREY R. MORRISON, KOHEI NISHIKAWA AND PHILIP NEEDLEMAN 1 Kinetic Analysis of the Renal Handling of 2,2,Bis(p-Chlorophenyl) Acetic Acid by the Rat. JOHN B. PRITCHARD 9 Studies with a New Antifolate 2,4-Diamino-5-Adamantyl-6-Methylpynimidine (DAMP): Tissue Distnbution and Disposition of 2,4-Diamino-5-Ada...

New 1,5-tetra alkyl methyl- phenyl-1H-pyrimido[4,5-e][1,3,4]thiadiazine-3,7-diamine were synthesized via the cyclocondensation of 2-(5-bromo-2-chloro-6-methylpyrimidin-4-yl)-2-methylhydrazine with phenylthioisothiocyanate and further replacement of chlorine atom on the seven number position of pyrimido[4, 5- e][1, 3, 4]thiadiazin by appropriate secondary amines in simple and efficient methods.

New 1,5-tetra alkyl methyl- phenyl-1H-pyrimido[4,5-e][1,3,4]thiadiazine-3,7-diamine  were synthesized via the cyclocondensation of 2-(5-bromo-2-chloro-6-methylpyrimidin-4-yl)-2-methylhydrazine with phenylthioisothiocyanate  and further replacement of chlorine atom on the seven number position of pyrimido[4, 5- e][1, 3, 4]thiadiazin by appropriate secondary amines  in simple and efficient methods. 

Moraxella (Branhamella) catarrhalis is an important cause of otitis media and sinusitis in children and of lower respiratory tract infections in adults. Lipooligosaccharide (LOS) is a major surface antigen of the bacterium and elicits bactericidal antibodies. Treatment of the LOS from strain ATCC 25238 with anhydrous hydrazine reduced its toxicity 20,000-fold, as assayed in the Limulus amebocyt...

Bacterial response to nitric oxide (NO) is of major importance since NO is an obligatory intermediate of the nitrogen cycle. Transcriptional regulation of the dissimilatory nitric oxides metabolism in bacteria is diverse and involves FNR-like transcription factors HcpR, DNR, and NnrR; two-component systems NarXL and NarQP; NO-responsive activator NorR; and nitrite-sensitive repressor NsrR. Usin...

Mutants from Schizosaccharomyces pombe deficient in the regulation of thiamine-repressible acid phosphatase have been isolated. Mutants expressing derepressed levels of the enzyme in the presence and absence of thiamine map in three genes, tnrl, tnr2 and tnr3. mRNA levels of the pho4 gene (coding for thiamine repressible acid phosphatase) and another thiamine-regulatable gene, thi3 (coding for ...

The ongoing increase in anthropogenic carbon dioxide (CO2) emissions is changing the global marine environment and is causing warming and acidification of the oceans. Reduction of CO2 to a sustainable level is required to avoid further marine change. Many studies investigate the potential of marine carbon sinks (e.g. seagrass) to mitigate anthropogenic emissions, however, information on storage...