A potential role of alkaloid extracts from Salsola species (Chenopodiaceae) in the treatment of Alzheimer's disease

From the aerial parts of Salsola oppositofolia, S. soda and S. tragus an alkaloid extract was obtained and tested to evaluate antioxidant and anti-cholinesterase activities. The in vitro study of the antioxidant activity by the DPPH method revealed a significant activity of Salsola alkaloid extracts with IC₅₀ values ranging from 16.30 μg/mL for S. oppositifolia to 26.17 μg/mL for S. tragus. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities were evaluated. S. tragus alkaloid extract exerted the highest inhibitory activity against AChE (IC₅₀ of 30.2 μg/mL) and BChE (IC₅₀ of 26.5 μg/mL). Interestingly, S. soda and S. oppositifolia exhibited a selective inhibitory activity against BChE with IC₅₀ values of 34.3 μg/mL and 32.7 μg/mL, respectively. Tetrahydroisoquinoline alkaloids were identified and quantified by GC/MS analysis.     

Synthesis and evaluation of N-substituted indole-3-carboxamide derivatives as inhibitors of lipid peroxidation and superoxide anion formation

The in vitro antioxidant effects of novel N-substituted indole-3-carboxamides (I3CDs) 1-10 on rat liver microsomal NADPH-dependent lipid peroxidation (LP) levels and their free radicals scavenging properties were determined by the inhibition of superoxide anion formation (SOD). Among the synthesized compounds, 4, 5, 8 and 9 significantly inhibited SOD with an inhibition range at 84–100% at 10^{? 3} M concentration. The presence of halo substituents both ortho- and para- positions of these compounds resulted 100% inhibition of SOD. Comparison the activity results of halogenated and non-halogenated derivatives suggested that the halogenated compounds are more active than the non-halogenated compounds. On the other hand, the introduction of a para fluoro benzyl in the 1-position of indole (compounds 7, 8) has more impact on the SOD inhibition when the benzamide ring was mono halogenated. However, none of other compounds had a significant inhibitory effects on the level of lipid peroxidation.     

Hierarchies of evolutionary radiation in the world’s most species rich vertebrate group,the Neotropical Pristimantis leaf litter frogs

The Neotropical leaf litter frog genus Pristimantis is very species-rich, with 526 species described to date, but the full extent of its diversity is much higher and remains unknown. This study explores the phylogenetic processes and resulting evolutionary patterns of diversification in Pristimantis. Given the well-recognised failure of morphology- and community-based species groups to describe diversity within the genus, we apply a new test for the presence and phylogenetic distribution of higher evolutionary units. We developed a phylogeny based on 260 individuals encompassing 149 Pristimantis presumed species, sampled at mitochondrial and nuclear genes (3718 base pair alignment), combining new and available sequence data. Our phylogeny broadly agrees with previous studies, both in topology and age estimates, with the origin of Pristimantis at 28.97 (95% HDP =21.59 – 37.33) million years ago (MYA). New taxa that we add to the genus, which had not previously been included in Pristimantis phylogenies, suggest considerable diversity remains to be described. We assessed patterns of lineage origin and recovered 14 most likely (95% CI: 13–19) phylogenetic clusters or higher evolutionary significant units (hESUs) within Pristimantis. Diversification rates decrease towards the present following a density-dependent pattern for Pristimantis overall and for most hESU clusters, reflecting historical evolutionary radiation. The timing of diversification suggests that geological events in the Miocene, such as Andes orogenesis and Pebas system formation and drainage, may have had a direct or indirect impact on the evolution of Pristimantis and thus contributed to the origins of evolutionary independent phylogenetic clusters.     

Molecular phylogenetic diversity in the widespread lizard Cercosaura ocellata (Reptilia: Gymnophthalmidae) in South America

For a long time, Cercosaura ocellata was considered polytypic, with three subspecies: C. ocellata ocellata, C. ocellata petersi and C. ocellata bassleri. Recently, C. ocellata bassleri was elevated to full species, based on analysis of a few molecular samples from Peru. This species complex is widely distributed in South America, occurring in Amazonia, Cerrado, Atlantic forest and Pampa biomes. The monophyly and species diversity of C. ocellata are still unstudied. Here, we infer phylogenetic relationships and species diversity of this group analysing 2326 base pairs of three mitochondrial (12S, 16S, and ND4) and one nuclear (c-mos) genes. Our taxon sampling of 115 specimens includes 72 samples of C. ocellata and sequences of other Cercosaura species and closely related Cercosaurinae. Maximum likelihood phylogenetic analysis recovered the monophyly of Cercosaura and that of C. ocellata with strong support. Our analyses suggest that C. ocellata is a complex of cryptic species, which possibly started diversifying in Amazonia.     

A large-scale inventory of liana diversity in tropical forests of South Eastern Ghats,India

Among the plant life-forms, lianas, the wood climbers still remain less studied than trees. The forests of Eastern Ghats of India are also relatively under studied compared with the Western Ghats biodiversity hotspot. We conducted a large-scale, landscape-level investigation of liana diversity in six hill complexes of the South Eastern Ghats, which covers 4297 km². We divided the study area into 6.25 km × 6.25 km grids and within each grid a 0.5 ha (5 m × 1000 m) transect was established and all lianas ≥1.5 cm diameter at breast height (dbh) were inventoried in 110 transects totalling a 55-ha area. Liana diversity totalled 143 species in 83 genera and 37 families in the 55 ha sampled. Of these 20 species (28.6%) were endemic to peninsular India and 7 (10%) species belonged to the rare and endangered category. Liana species richness ranged from 8–35 species and density 95–544 individuals per transect. A total of 32 033 liana individuals were enumerated in the 55 ha and the mean abundance was 291 individuals per transect. Across sites, liana abundance varied significantly, but not species richness and basal area. Asclepiadaceae (13 species, 9%) and Apocynaceae (11 species, 8%) constituted the most diverse liana families, followed by Papilionaceae, Vitaceae (10 each, 7%), Convolvulaceae, Mimosaceae, Oleaceae (8 each, 6%), Capparaceae, Rhamnaceae (7 each, 5%) and Menispermaceae (5 species, 3%). In liana stem size distribution, the lowest diameter class (1.5–3 cm dbh) accounted for greatest species richness (137 species, 96%), abundance (27 358 individuals, 85%) and basal area (13.5 m², 36%). The stem twiners were the predominant climber type in terms of species richness (61 species, 42.65%), whereas the armed scramblers were abundant due to stem density (21 571 individuals, 67.34%). The dispersal modes of lianas, assessed by fruit types, revealed zoochory as the prevalent mode (85 species, 59%) indicating the faunal dependence of lianas in the Eastern Ghats landscape. Liana diversity of the Eastern Ghats was compared with inventories made across the tropics. With these baseline data generated on lianas, the importance of biodiversity conservation of the already fragmented South Eastern Ghats region is underlined and potential areas of further research on liana ecology are suggested.     

Synthesis of N-substituted indole-2-carboxamides and investigation of their biochemical responses against free radicals

The antioxidant role of novel N-substituted indole-2-carboxamides (I2CDs) was investigated for their inhibitory effects on superoxide anion (O₂^? ) and lipid peroxidation (LP). Among the synthesized I2CDs, 3, 4, 6, 8 and 9 significantly inhibited O₂^{· ?} with an inhibition range at 70–98%. Examination of substituent effects on activity showed that both the ortho- and para-positions of the benzamide residue needs to be dichlorinated in order to get a maximum inhibitory effect on superoxide anion. In general, halogenated derivatives were found more active then the non-halogenated ones. However, none of the I2CDs had a significant inhibitory effects on the level of lipid peroxidation; only compounds 7 and 10 moderately decreased LP levels by over 50% at 10^{? 3} M concentrations.