The new Southeast Asian goblin spider genus Aposphragisma (Araneae, Oonopidae): diversity and phylogeny

The new genus Aposphragisma (Araneae, Oonopidae, Oonopinae) comprising the new species A. baltenspergerae, A. borgulai, A. brunomanseri, A. confluens, A. dayak, A. dentatum, A. draconigenum, A. hausammannae, A. helvetiorum, A. kolleri, A. menzi, A. monoceros, A. nocturnum, A. retifer, A. rimba, A. salewskii, A. scimitar, A. sepilok and A. stannum is described. It is characterised by very hard bodied, strongly sclerotized species with completely armoured prosoma and strongly sclerotized ventral and dorsal abdominal scuta. Aposphragisma gen. nov. is placed within the Gamasomorpha-group sensu Saaristo (2001). Descriptions and illustrations are given for all new species. A phylogenetic analysis based on 40 characters using Prethopalpus fosuma, Gamasomorpha asterobothros, G. cataphracta, G. seximpressa, Xestaspis biflocci, X. kandy and X. paulina as outgroup-taxa and Cortestina thaleri (Oonopidae, Sulsulinae) as the root is presented and discussed. Furthermore it is shown that females of Aposphragisma gen. nov. possess complex internal genitalia. The members of the new genus are ground-dwelling litter inhabitants restricted to Southeast Asian lowland and montane forests, with more than 60% of the species only known from single localities. They are presumed to be negatively affected by the massive destruction of pristine forest habitats within their range. This work has been conducted within the framework of the Planetary Biodiversity Inventory (PBI) of Oonopidae (see http://research.amnh.org/oonopidae).

Moderate concentrations of 4-O-methylhonokiol potentiate GABAA receptor currents stronger than honokiol

BACKGROUND Magnolia bark preparations from Magnolia officinalis of Asian medicinal systems are known for their muscle relaxant effect and anticonvulsant activity. These CNS related effects are ascribed to the presence of the biphenyl-type neolignans honokiol and magnolol that exert a potentiating effect on GABAA receptors. 4-O-methylhonokiol isolated from seeds of the North-American M. grandiflora was compared to honokiol for its activity to potentiate GABAA receptors and its GABAA receptor subtype-specificity was established. METHODS Different recombinant GABAA receptors were functionally expressed in Xenopus oocytes and electrophysiological techniques were used determine to their modulation by 4-O-methylhonokiol. RESULTS 3μM 4-O-methylhonokiol is shown here to potentiate responses of the α₁β₂γ₂ GABAA receptor about 20-fold stronger than the same concentration of honokiol. In the present study potentiation by 4-O-methylhonokiol is also detailed for 12 GABAA receptor subtypes to assess GABAA receptor subunits that are responsible for the potentiating effect. CONCLUSION The much higher potentiation of GABAA receptors at identical concentrations of 4-O-methylhonokiol as compared to honokiol parallels previous observations made in other systems of potentiated pharmacological activity of 4-O-methylhonokiol over honokiol. GENERAL SIGNIFICANCE The results point to the use of 4-O-methylhonokiol as a lead for GABAA receptor potentiation and corroborate the use of M. grandiflora seeds against convulsions in Mexican folk medicine.