The transformation of Saperda calcarata (Coleoptera: Cerambycidae) into a cellulose digester through the inclusion of fungal enzymes in its diet

The larvae of the aspen borer, Saperda calcarata , which feed on the inner bark and sapwood of living aspen stems, are unable to digest cellulose. However, they can be transformed into cellulose digesters by adding the active cellulase complex of the fungus, Penicillium funiculosum to their diet. S. calcarata larvae are preadapted to exploit the digestive potential of ingested microbial enzymes. We argue that ingested fungal enzymes may be responsible for cellulose digestion in many, perhaps most or even all, cellulose digesting cerambycid beetles.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47768/1/442_2004_Article_BF00377333.pd

Chemical composition of the leaf essential oil of grapefruits ( Citrus paradisi Macf.) in relation with the genetic origin

International audienceThe composition of twenty-four samples of essential oil isolated from leaves of Citrus paradisi Macf. growing in a northern area of citrus cultivation in Mediterranean climate (Corsica) was investigated by GC (RI), GC-MS and C-13 NMR. Thirty-six compounds accounting for 94.9-99.3% of the oil composition were identified. The oils contained mainly monoterpene hydrocarbons and specially sabinene (up to 60.2%),(E)-beta-ocimene (up to 15.0%) and punctually gamma-terpinene (up to 56.1%), beta-pinene (up to 30.9%) and p-cymene (up to 12.5%). The twenty-four compositions were submitted to k-means partitioning and principal component analysis, which allowed the distinction of one homogeneous group of twenty-two grapefruits (main compound sabinene, mean = 47.1%). This group included eighteen cultivars derived by mutation from the ancestral grapefruit tree (Duncan) and four cultivars known to be interspecific hybrids. Two out group cultivars were clearly differentiated from others by original chemical compositions, in agreement with their hybrid origin

Effect of particle size reduction and crystalline form on dissolution behaviour of nimesulide

The objective of this study was to develop and examine innovative and very simple and easily scalable techniques able to improve solubility and/or dissolution rate and thus oral bioavailability of nimesulide. Three different nimesulide batches were obtained by three different laboratory-scale methods: Method A (Batch A) used crystallization by solvent evaporation in a nanospray dryer, Method B (Batches G and GLN) involved cryo-milling, and Method C (Batch Neu) dispersed nimesulide in Neusilin(A (R)) UFL2. All the nimesulide batches were fully characterized for chemical stability, thermal behaviour, physicochemical and micromeritics properties, and intrinsic dissolution and particle dissolution rates. Batch A not only showed a good reduction in particle size but also exhibited a reduced degree of crystallinity by both differential scanning calorimetry and X-ray powder diffractometry, which could explain the increase in intrinsic dissolution rate (IDR) and particle dissolution. Batch GLN showed an acceptable increase in IDR, probably caused by a slight decrease in the degree of crystallinity, and good improvement in dissolution rate due to a certain decrease in particle size. Batches G and native crystals exhibited very close IDRs, while G showed somewhat higher particle dissolution, probably attributed to the particle size reduction. The dispersion of nimesulide in Neusilin UFL2 in a 1:6 drug-polymer ratio made it possible to recover anamorphous powder, as proven by thermal analysis and X-ray powder diffractometry, characterized by pronounced particle size reduction to nanometric dimensions. Both amorphous character and nanometric dimensions could account for the fastest particle dissolution during the first 10 min of the experiment. The stability study conducted according to the International Conference on Harmonization (ICH) confirmed the good chemical and physicochemical stability of all the batches