Larvicidal, insecticidal, brine shrimp cytotoxicity and anti-oxidant activities of Diospyros kaki [L.] reported from Pakistan

Diospyros kaki is cultivated in different agro-ecological zones of Pakistan, especially in Malakand division. The current study was designed to investigate the hide potential of the vulnerable species of the plant. Aqueous extracts of Diospyros kaki leaves were screened for larvicidal, insecticidal cytotoxic and antioxidant activities. The extract exhibited moderate to outstanding larvicidal activity [100 to 28%] at 100, 80, 70, 50, 40, 30, 20 and 10% concentrations respectively after 24 hours, showing 42% LCso. Permitrin displayed 100% lethality at 0.3%. The extract demonstrated outstanding cytotoxic action against brain shrimps nauplii [Artemia salina], showing 10 ppm LC[50] which is closed to the LC[5]o [9.8jtig/ml] of standard drug Etoposide. Similarly profound insecticidal potential [100%] was recorded after 15 min against Cimex lectularius. In DPPH scavenging activity the extract demonstrated moderate 30.22%, while Quercetin, Gallic acid and Acetic acid showed 98, 96 and 97% activity respectively at lOOppm. Thus on the basis of our finding it could be concluded that the decoction of the leaves of D. kaki is a good natural alternative for the control of insects and neoplasia

PH dependent properties of chicken and beef cytochrome C oxidases

The pH dependent properties of mono-meric form of cytochrome c oxidases isolated from beef and chicken hearts tissue are described and compared with those of the enzyme dimer. Dimeric form of oxidase dissociated into Monemeric state of enzyme with increase of pH. The absorbtion spectra of alkaline incubated oxidase at pH 9.5 to pH 11.0 showed lambda Fe+2 maximum at 441 nm compared to 444 nm for typical dimeric oxidase at pH 7.4. The maxima for alpha Fe+2 are indicated at 604 nm for both neutral and alkaline incubated oxidase. The difference spectra [reduced-Co minus reduced] showed absorption maxima at 430 nm for alkaline incubated oxidase and 430 nm for dimeric oxidase. Carbon monoxide titration showed that alkaline incubated oxidase [at or above pH 10.5] reacted with approximately twice the amount of carbon monoxide compared to the oxidase at neutral pH of equal haem A contents. Titration of the purified monomers showed the reaction of carbon monoxide with only one of the two haem A contents of the oxidase similar to that of dimeric enzymes