Isolation of 2-Phenylacetamide as a Plant Growth Regulator Produced by Actinomyces

Isolation and screening tests were carried out in order to find microorganisms which were able to produce citric acid directly from blackstrap molasses. Some strains were obtained which accumulate considerable quantities of citric acid. Certain temperature changes during the course of incubation were found to increase the yield of citric acid.

The present investigation was undertaken to see if a simple method could be found to improve the yield of citric acid from blackstrap molasses, and we could obtain the yield of more than 70% from the untreated molasses using a newly isolated strain of Asp. niger.     

Production of Extracellular l-Asparaginases by Microorganisms

A variety of microorganisms were tested for their extracellular l-asparaginase productivity and it was found that many bacteria, fungi and yeasts are positive for it. Especially some strains in the genera Pseudomonas, Candida and Rhodotorula were able to produce a large amounts of the enzyme. Escherichia coli, however, that contained intracellular enzyme was unable to produce extracellular one. In enzymological properties some differences were noted among these extracellular enzymes. Pseudomonas asparaginase showed glutaminase activity too, but the asparaginases of Candida and Rhodotorula were unable to hydrolyze glutamine. Candida l-asparaginase was most stable to heat-treatment.     

Spawning Inhibitor in Gonads of the Starfish,Asterina pectinifera

A biologically active substance which inhibits spawning of the starfish, Asterina pectinifera, has been isolated from gonads of the same organism and identified as l-glutamic acid.     

Stereochemistry of Pyrethrosin,Cyclopyrethrosin Acetate and Isocyclopyrethrosin Acetate

The acid cyclization product from pyrethrosin has been proved to be a (1:1)-mixture of cyclopyrethrosin acetate containing a Δ³⁽⁴⁾-double bond and isocyclopyrethrosin acetate with a Δ⁴⁽¹⁵⁾-double bond through the reinvestigation. NMR and ORD studies on their derivatives led us to assign revised stereochemistry to pyrethrosin and its related compounds.     

The Chemical Constitution of Rubrofusarin

Alkaline degradation of rubrofusarin and nor-rubrofusarin were studied; nor-rubrofusarin readily underwent hydrolysis to give a tetrahydroxynaphthalenc, acetone, and acetic acid; whereas, rubrofusarin, after prolonged time of hydrolysis, yielded a β-methoxytrihydroxynaphthalene instead of the naphthol. Physical and chemical studies revealed that the naphthol is 1,3,6,8-tetrahydroxynaphthalene and it has been confirmed by the synthesis from chromotropic acid (disodium salt). Thus, evidently, rubrofusarin has a naphthalene nucleus to which a methoxyl group is attached at β-position. The formation, on the hydrolysis, of acetone and acetic acid, along with the naphthol, indicates the presence of 2-methyl-γ-pyrone structure in rubrofusarin.     

Fabrication of chitin-chitosan/nano TiO2-composite scaffolds for tissue engineering applications

In this study, we prepared chitin-chitosan/nano TiO(2) composite scaffolds using lyophilization technique for bone tissue engineering. The prepared composite scaffold was characterized using SEM, XRD, FTIR and TGA. In addition, swelling, degradation and biomineralization capability of the composite scaffolds were evaluated. The developed composite scaffold showed controlled swelling and degradation when compared to the control scaffold. Cytocompatibility of the scaffold was assessed by MTT assay and cell attachment studies using osteoblast-like cells (MG-63), fibroblast cells (L929) and human mesenchymal stem cells (hMSCs). Results indicated no sign of toxicity and cells were found attached to the pore walls within the scaffolds. These results suggested that the developed composite scaffold possess the prerequisites for tissue engineering scaffolds and it can be used for tissue engineering applications.     

Fabrication of chitosan/poly(caprolactone) nanofibrous scaffold for bone and skin tissue engineering

Chitosan/poly(caprolactone) (CS/PCL) nanofibrous scaffold was prepared by a single step electrospinning technique. The presence of CS in CS/PCL scaffold aided a significant improvement in the hydrophilicity of the scaffold as confirmed by a decrease in contact angle, which thereby enhanced bioactivity and protein adsorption on the scaffold. The cyto-compatibility of the CS/PCL scaffold was examined using human osteoscarcoma cells (MG63) and found to be non toxic. Moreover, CS/PCL scaffold was found to support the attachment and proliferation of various cell lines such as mouse embryo fibroblasts (NIH3T3), murine aneuploid fibro sarcoma (L929), and MG63 cells. Cell attachment and proliferation was further confirmed by nuclear staining using 4',6-diamidino-2-phenylindole (DAPI). All these results indicate that CS/PCL nanofibrous scaffold would be an excellent system for bone and skin tissue engineering.