The terminal enzymatic step in piperine biosynthesis is co-localized with the product piperine in specialized cells of black pepper (Piper nigrum L.)

Piperine (1-piperoyl piperidine) is responsible for the pungent perception of dried black pepper (Piper nigrum) fruits and essentially contributes to the aromatic properties of this spice in combination with a blend of terpenoids. The final step in piperine biosynthesis involves piperine synthase (PS), which catalyzes the reaction of piperoyl CoA and piperidine to the biologically active and pungent amide. Nevertheless, experimental data on the cellular localization of piperine and the complete biosynthetic pathway are missing. Not only co-localization of enzymes and products, but also potential transport of piperamides to the sink organs is a possible alternative. This work, which includes purification of the native enzyme, immunolocalization, laser microdissection, fluorescence microscopy, and electron microscopy combined with liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS), provides experimental evidence that piperine and PS are co-localized in specialized cells of the black pepper fruit perisperm. PS accumulates during early stages of fruit development and its level declines before the fruits are fully mature. The product piperine is co-localized to PS and can be monitored at the cellular level by its strong bluish fluorescence. Rising piperine levels during fruit maturation are consistent with the increasing numbers of fluorescent cells within the perisperm. Signal intensities of individual laser-dissected cells when monitored by LC-ESI-MS/MS indicate molar concentrations of this alkaloid. Significant levels of piperine and additional piperamides were also detected in cells distributed in the cortex of black pepper roots. In summary, the data provide comprehensive experimental evidence of and insights into cell-specific biosynthesis and storage of piperidine alkaloids, specific and characteristic for the Piperaceae. By a combination of fluorescence microscopy and LC-MS/MS analysis we localized the major piperidine alkaloids to specific cells of the fruit perisperm and the root cortex. Immunolocalization of native piperine and piperamide synthases shows that enzymes are co-localized with high concentrations of products in these idioblasts.

[Interrelationship between peripartal metabolism, performance, morbidity and productive life in a herd of Holstein-Friesian heifers]

OBJECTIVE

The aim of this study was to determine the relationship between the heifers' peripartal metabolism, milk yield data and the productive life achieved. Furthermore, the influence of fertility, back fat thickness and morbidity on the productive life was evaluated.

MATERIAL AND METHODS

Metabolic data and back fat thickness measurements, determined between 2004 and 2005 in a herd of Holstein-Friesian dairy cows, were analysed retrospectively. Additionally, the age reached by the 207 (at that time) heifers as well as data on culling, fertility, milk yield and morbidity were determined with the help of the herd management system and related to the laboratory findings.

RESULTS

Heifers with the shortest productive life of < 12 months had the significantly lowest (p < 0.0001) milk yield. The shortest productive life of < 12 months was associated with the significantly lowest (p < 0.0001) oestradiol concentrations 3 days post partum (p. p.) and the significantly smallest (p < 0.0001) albumin concentrations p. p. Furthermore, heifers with the shortest productive life of < 12 months had the significantly lowest (p < 0.0001) cholesterol concentrations 28 days ante partum (a. p.) and p. p. The data showed that heifers with a short productive life had a tendency for lower back fat thickness, tendencially lower oestradiol concentrations 10 days a. p., a trend to lower fertility (regarding inseminations per animal) and an increased incidence of mastitis, stillbirths and endometritis.

CONCLUSION AND CLINICAL RELEVANCE

The lowest albumin and cholesterol concentrations of the heifers with a short productive life arose from an inadequate food intake. Oestradiol concentration also decreased during the state of energy deficiency. The low oestradiol concentrations 10 days a. p. can lead to repeated stillbirths in such heifers, and this increased the number of clinical endometritis. Furthermore, the low milk yield corresponded with an energy deficiency in these heifers. These results were supported by the low back fat thickness of these animals, which consequently led to poor fertility. As a consequence, for a longer productive life, special attention should be paid to heifers during the periparturient period, in particular focusing on their food intake and body condition.

Beziehungen zwischen peripartalem Stoffwechsel, Leistung sowie Morbidität bei Holstein-Friesian-Kalbinnen eines Bestandes und deren Nutzungsdauer

Ziel der Studie war, bei Kalbinnen die Beziehung zwischen peripartalem Stoffwechsel, Milchleistung, Fruchtbarkeit sowie Krankheiten und der späteren Nutzungsdauer (ND) zu prüfen. Material und Methoden: Es erfolgte eine retrograde Analyse von Befunden des peripartalen Stoffwechsels und Messwerten der Rückenfettdicke (RFD), die 2004 und 2005 in einem Holstein-Friesian-Milchkuhbestand erhoben worden waren. Anschließend wurden ND, Abgangs-, Fruchtbarkeits- und Milchleistungsdaten sowie Krankheiten der damaligen 207 Kalbinnen mithilfe des Herden-Bestandsprogramms ermittelt und mit den Laborbefunden ins Verhältnis gesetzt. Ergebnisse: Kalbinnen mit der kürzesten ND von < 12 Monaten hatten die signifikant (p < 0,0001) niedrigste Milchleistung. Die kürzeste ND von < 12 Monaten ging einher mit der signifikant (p < 0,0001) niedrigsten Östradiolkonzentration 3 Tage post partum (p. p.), der signifikant (p < 0,0001) geringsten Albuminkonzentration post partum und der signifikant (p < 0,0001) niedrigsten Cholesterolkonzentration 28 Tage ante partum (a. p.) sowie post partum. Ferner fanden sich bei Kalbinnen mit einer ND von < 12 Monaten tendenziell geringere RFD, tendenziell niedrigere Östradiolkonzentrationen 10 Tage a. p., eine tendenziell schlechtere Fruchtbarkeit (Besamungen/Tier) sowie ein gehäuftes Auftreten von Mastitiden, Totgeburten und Endometritiden. Schlussfolgerung und klinische Relevanz: Die niedrigsten Albumin- und Cholesterolkonzentrationen der Kalbinnen mit der kürzesten ND von < 12 Monaten können auf eine ungenügende Futteraufnahme zurückzuführen sein. Die Östradiolkonzentration sinkt ebenfalls im Zustand des Energiemangels. Die niedrigen Östradiolkonzentrationen 10 Tage a. p. können zu den gehäuften Totgeburten solch kurzlebiger Kalbinnen führen, was wiederum die höhere Anzahl der klinischen Endometritiden bedingt. Auch die niedrige Milchleistung spricht für einen Energiemangel betreffender Tiere. Als Konsequenz daraus sollte für eine längere ND ein besonderes Augenmerk auf Kalbinnen im peripartalen Zeitraum gelegt werden, vor allem auf deren Futteraufnahme und Körperkondition.