Hyperforin accumulates in the translucent glands of Hypericum perforatum

BACKGROUND AND AIMS: Hypericum perforatum contains the therapeutically important compounds hypericin and hyperforin. Hypericin is known to accumulate in the dark glands. This investigation aimed to determine the accumulation site of hyperforin. METHODS: Dark and translucent glands as well as non-secretory tissue in leaves were manually isolated under the microscope. Hyperforin content was quantified by UV HPLC. Secretory structures were surveyed anatomically. KEY RESULTS: The hyperforin content of intact leaves was found to be about 3 mg g(-1) fresh tissue, whereas a content of about 7 mg g(-1) fresh material was found in isolated translucent glands. Hyperforin was found only to occur in minute amounts in dark glands (approx. 0.4 mg g(-1) fresh tissue). In non-secretory tissue no hyperforin was detected. CONCLUSIONS: The accumulation of hyperforin detected in the translucent glands supports the proposed hypothesis that hyperforin is synthesized by the same biosynthetic machinery as monoterpenes in the chloroplasts of cells delimiting the gland.     

Hyperforin Accumulates in the Translucent Glands of Hypericum perforatum

Annals of Botany 99: 1097–1100, 2007 Unfortunately in Fig. 1D     

Portable 24-analyte surface plasmon resonance instruments for rapid, versatile biodetection

Field use of surface plasmon resonance (SPR) biosensors for environmental and defense applications such as detection and identification of biological warfare agents has been hampered by lack of rugged, portable, high-performance instrumentation. To meet this need, we have developed compact multi-analyte SPR instruments based on Texas Instruments' Spreeta sensing chips. The instruments weigh 3 kg and are built into clamshell enclosures measuring 28 cm x 22 cm x 13 cm. Functions are divided between an electronics unit in the base of the box and a fluidics assembly in the lid. Automated valves and pumps implement an injection loop flow system that allows sensors to be exposed to sample, rinsed, and treated with additional reagents (such as secondary antibodies) under computer control. Injected samples flow over the surfaces of eight sensor chips fastened into a temperature-controlled silicone flowcell. Each chip has 3 sensing regions, for a total detection of 24 areas that can be simultaneously monitored by SPR. Coating these areas with appropriate antibodies or other receptors allows a sample to be screened for up to 24 different substances simultaneously. The instruments report refractive index (RI) values every second, with a typical noise level of 1-3 x 10(-6) RI units. The design of the device is described, and performance is illustrated with detection of six distinct analytes ranging from small molecules to whole microbes during the course of a single experiment.