Biogenetic studies in Syringa vulgaris L.: synthesis and bioconversion of deuterium-labeled precursors into lilac aldehydes and lilac alcohols

Syringa vulgaris L. inflorescences were fed with aqueous solutions of regioselectively deuterated compounds assumed to be precursors of lilac aldehyde and lilac alcohol, respectively. Volatiles were extracted by stir bar sorptive extraction (SBSE) and analyzed using enantioselective multidimensional gas chromatography/mass spectrometry (enantio-MDGC/MS); deuterium-labeled lilac aldehydes and lilac alcohols were separated from unlabeled stereoisomers on a fused silica capillary column, coated with heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-beta-cyclodextrin (DIME-beta-CD) (30%) in SE 52 (70%), as the chiral stationary phase. Feeding experiments with [5,5-(2)H(2)]mevalonic acid lactone 22 and [5,5-(2)H(2)]deoxy-d-xylose 23 indicate that the novel mevalonate independent 1-deoxy-d-xylose 5-phosphate/2C-methyl-d-erythritol 4-phosphate pathway is the dominant metabolic route for biosynthesis in lilac flowers. Additionally, bioconversion of deuterium-labeled d(5)-(R/S)-linalool 3, d(6)-(R)-linalool 21, d(5)-(R/S)-8-hydroxylinalool 6, d(5)-(R/S)-8-oxolinalool 7, d(5)-lilac aldehydes 8-11 and d(5)-lilac alcohols 12-15 into lilac during in vivo feeding experiments was investigated and the metabolic pathway is discussed. Incubation of petals with an aqueous solution of deuterated d(5)-(R/S)-linalool 3 indicates an autonomic terpene biosynthesis of lilac flavor compounds in the flower petals of lilac.     

Deep Gluteal Abscess in a Zebra (Equus burchelli boehmi)

A male zebra aged about 7 years, weighing approximately 250 kg showed signs of lameness on its hindquarter. It was treated by the zoo veterinarians symptomatically, and it recovered. However, there was recurrence of the symptoms after 1 month. The animal was treated with fluid, electrolyte, antibiotic, and analgesic therapy. The hematology and serum biochemistry profiles were tested and found within the normal range. The animal was tranquilized, and physical and external examinations were conducted. Radiological examination of hoof ruled out any chances of laminitis or any other hoof deformities. Per-rectal examination along with flexion and extension of the hind limbs could not reveal any abnormalities. However, there was no improvement, and finally it died. Postmortem examination revealed an internal deep gluteal abscess. This is a rare report of deep gluteal abscess in a zebra. The difficulties encountered in diagnosing the case and its serious possible complications and possible methods of diagnosing have been described, which may help future equine and wildlife vets in diagnosing such cases successfully and may help in saving the precious lives of the patients suffering from such conditions.     

甜菜杂种优势与核酸含量的关系

本文通过对典型的甜菜杂交组合的核酸含量与杂种优势关系的研究表明：两对真叶期ＤＮＡ含量超亲负优势与块根产量的超亲正优势，正好相反；八叶期ＤＮＡ含量的超亲正优势与块根产量的超亲优势一致，同时该期的含量和总核酸含量的超亲正优势与块根产糖量的超亲正优势基本一致。因而，上述两个叶龄期的ＤＮＡ含量以及八叶期总核酸含量可作为鉴定杂种优势的生理指标。     

Methane dynamics of landfill cover soils and aspects of their classification

The methane dynamics of soils covering a landfill in Oldenburg, Lower Saxony, was investigated in 1996. The methane concentration was often < 20 nmol (dry g)^?1 within the cover layer and up to 9950 nmol (dry g)^?1 within the refuse body. The methane production rates correlated positively with the methane concentrations and were mostly < 10 nmol (dry g)^?1 d^?1 within the cover layer and up to 1090 nmol (dry g)^_1 d^_1 within the refuse body. The methane oxidation rates varied between 38.0–2310 nmol (dry g)^?1 d^?1. The methane emission rates showed values of up to 574 mol m^?2 h^?1, but in two cases no emission of methane was found. The data indicate that the methano-genesis of the deep refuse layers did not substantially affect the methane behaviour of the upper soil sections. It is likely that the emission of methane from landfills can be reduced by thick well aerated cover layers. The term “Reduktosol” for landfill soils is critically discussed.