Production of 4-Ipomeanol, an anticancer agent from the root tubers and rhizogenic callus of Ipomoea batatas Lam.: A Comparative study.

A comparative study was done on the production of 4-ipomeanol from root tubers of Ipomoea batatas and its rhizogenic callus. Best callusing response was obtained on MS medium supplemented with 11 µM NAA (α-Naphthaleneacetic acid) and 1 µM KIN (Kinetin). Effect of various elicitors (Fusarium solani, chitin and chitosan) on the production of 4-ipomeanol was studied. Methanol extract of the samples were purified by column chromatography and detected using TLC. Identification of 4-ipomeanol was confirmed using HPLC and quantified spectrophotometrically. A mass spectrum was recorded to confirm the presence of 4-ipomeanol. The calli grown under chitin produced highest (6.61mg g-1) amount of 4-ipomeanol. This is the first report on in vitro production of 4-ipomeanol from I. batatas. Since 4-ipomeanol is reported to be present only in I. batatas, this study would help in standardizing protocols for large scale production without affecting its natural flora.

Biotechnological processes for chitin recovery out of crustacean waste: a mini-review

Background: Chitin is an important natural resource. The annual worldwide production is estimated in approximately 10(10)-10(12) ton. It is produced by arthropods (insects and crustaceans), molluscs and fungi. Its main biological function is structural. Crustacean shells are the most important chitin source for commercial use due to its high content and ready availability. Chitin and its derivatives have great economical value because of their numerous applications: food, cosmetics, pharmaceuticals, textile industries, waste water treatment and agriculture. In nature, chitin is closely associated with proteins, minerals, lipid and pigments, which have to be removed. Results: Several techniques to extract chitin from different sources have been reported. The most common method for recovery of chitin from crustacean shells is the chemical procedure. It involves two mayor steps: elimination of inorganic matter (demineralization) and extraction of protein matter (deproteination) using strong acids and bases. However, these processes may cause depolymerization affecting the polymer properties such as molecular weight, viscosity and degree of acetylation. In addition, the chemical purification of chitin is hazardous, energy consuming and threatening to the environment. As an alternative to the chemical process, different biological processes have been investigated: microbiological fermentation and methodologies using enzymatic crude extracts or isolated enzymes. Conclusions: The results reported are extremely variable; however, they offer new perspectives for the production of chitin with the concomitant reduction of the environmental impact.

Effect of the chitin synthesis inhibitor triflumuron on the development, viability and reproduction of Aedes aegypti

The control of Aedes aegypti is impaired due to the development of resistance to chemical insecticides. Insect Growth Regulators (IGR) exhibit distinct mechanisms of action and are considered potential vector control alternatives. Studies regarding the effects of sublethal IGR doses on the viability of resulting adults will contribute to eval-uating their impact in the field. We analyzed several aspects of Ae. aegypti adults surviving exposure to a partially lethal dose of triflumuron, a chitin synthesis inhibitor. A highly significant difference in the proportion of males and females was noted in the triflumuron-exposed group (65.0 percent males) compared to the controls (50.2 percent males). Triflumuron affected adult longevity, particularly for females; after 16 days, only 29.2 percent of males and 13.8 percent of females were alive, in contrast with 94 percent survival of the control mosquitoes. The locomotor activity was reduced and the blood-feeding ability of the treated females was also affected (90.4 percent and 48.4 percent of the control and triflumuron-exposed females, respectively, successfully ingested blood). Triflumuron-surviving females ingested roughly 30 percent less blood and laid 25 percent fewer eggs than the control females. The treated males and females exhibited a diminished ability to copulate, resulting in less viable eggs.