Showing papers on "Azadirachta published in 1979"

Seed Dispersal by Baboons in the Shai Hills, Ghana

Abstract: Baboon dung was collected in the Shai Hills, Ghana at 4—wk intervals from November 1975 to January 1977, and was planted in sterilized soil in order to estimate the viable seed content of the dung. A total of 6,465 seedlings germinated, belonging to 59 species, although 70% of the seedlings belonged to 2 fleshy—fruited species. The species composition varied from month to month as did the relative importance of dry fruits. Germination of ingested seeds (removed from dung) was significantly improved over that of fresh seeds in 3 of 4 species tested (Securinega virosa, Azadirachta indica, and Nauclea latifolia). The 4th species, Diospyros mespiliformis, showed no significant improvement. See full-text article at JSTOR

Preparative Reversed-Phase Liquid Chromatographic Isolation of Azadirachtin from Neem Kernels (1)

Abstract: Azadirachtin is a tetranortriterpenoid insect feeding deterrent and growth regulator present in the kernels of the neem tree, Azadirachta indica A. Juss. A procedure was developed whereby 8.7 g of >90% pure azadirachtin was obtained from 48.2 kg of neem kernels by the use of open-column reversed-phase liquid chromatography on Phase-bonded C-18 Hi-Flosil and high-performance liquid chromatography on μ Bondapak C-18 for monitoring (217 nm) the purification.

Neem kernel as an ovipositional repellent for Spodoptera litura (F.) moths

Abstract: Laboratory and nursery tests showed that a 2% neem (Melia azadirachta L.) seed kernel suspension in water was effective as a repellent and ovipositional deterrent for moths of the tobacco caterpillar,Spodoptera litura (F.). The mean number of eggs laid on treated tobacco seedlings was 37 3 as against 1715 on control seedlings. As a consequence of the moths being repelled from the treated plants, they laid more eggs on the cloth and the glass surface in glass jar experiments. Repellency was even more pronounced when the moths were released in treated and untreated nylon-netting-caged nursery beds; the mean number of eggs laid on treated seedlings was then only 749 as against 19,713 in control beds.

Studies on plant gums. Proteases in neem (Azadirachta indica) gum

Abstract: Proteolytic activity was detected in neem (Azadirachta indica) exudate gum when tested with casein and albumin as substrates. The enzyme activity was separated into two fractions by chromatography on TEAE-cellulose after EDTA treatment. Both the enzyme fractions were fairly stable to high temperatures and wide range of pH conditions. The pH optima were found to be around 6.5. Phenylmethyl sulphonylfluoride inhibited the activity of both the fractions. EDTA, Β-mercaptoethanol, tosylamide phenylethylchloromethylketone, tosyllysine chloroimethylketone,p-chloromercuribenzoate and dithiobis-2-nitrobenzoie acid did not affect the activity of the two enzyme fractions. The two fractions had no hydrolytic action on a variety of synthetic substrates tested.

Studies on plant gums. Role of calcium in polysaccharide-protein interaction in the neem (Azadirachta indica) gum

Abstract: The partial removal of tightly bound Ca2+ from dialysed neem (Azadirachta indica) gum, resulted in the release of a basic protein from a highly anionic polysaccharide-protein complex as evidenced by chromatographic studies on TEAE-cellulose. Complete removal of Ca2+ caused, in addition, the release of a minor heteropolysaccharide which was found in association with the basic protein. These processes were reversed on the addition of Ca2+. The gum, in addition, contained a protein-rich component accounting for 35% protein and 7.5% total carbohydrate. This component behaved as a distinct entity during ion-exchange chromatography of the native gum solutions, or which were either partially or completely depleted of bound Ca2+.