Endo-fenchyl acetate rich essential oil of Strobilanthes sessilis Nees inflorescence and its characterisation using GC, GC-MS, and NMR techniques.

Strobilanthes Blume is a genus in the family Acanthaceae, with many species endemic to the Indian subcontinent. Strobilanthes sessilis Nees is endemic to the southern Western Ghats of India. The essential oil of dried inflorescence of S. sessilis was extracted using hydrodistillation method and the chemical composition was determined using GC and GC-MS techniques, which revealed the major compound to be endo-fenchyl acetate (89.33%). Other minor compounds like endo-fenchol (3.74%), (E)-caryophyllene (1.07%), and limonene and ß-phellandrene (0.55%) were also observed. The major diastereomer of fenchyl acetate was determined using 2D-NMR techniques like HSQC, HMBC, and ROESY to confirm the endo configuration. The optical rotation of the oil in different solvents deduced that the laevorotatory enantiomer of endo-fenchyl acetate as the major or single compound. S. sessilis could be further explored as a major source of endo-fenchyl acetate, which has high importance in flavouring and other biological applications.

DNA barcode authentication of wood samples of threatened and commercial timber trees within the tropical dry evergreen forest of India.

BACKGROUND: India is rich with biodiversity, which includes a large number of endemic, rare and threatened plant species. Previous studies have used DNA barcoding to inventory species for applications in biodiversity monitoring, conservation impact assessment, monitoring of illegal trading, authentication of traded medicinal plants etc. This is the first tropical dry evergreen forest (TDEF) barcode study in the World and the first attempt to assemble a reference barcode library for the trees of India as part of a larger project initiated by this research group. METHODOLOGY/PRINCIPAL FINDINGS: We sampled 429 trees representing 143 tropical dry evergreen forest (TDEF) species, which included 16 threatened species. DNA barcoding was completed using rbcL and matK markers. The tiered approach (1st tier rbcL; 2nd tier matK) correctly identified 136 out of 143 species (95%). This high level of species resolution was largely due to the fact that the tree species were taxonomically diverse in the TDEF. Ability to resolve taxonomically diverse tree species of TDEF was comparable among the best match method, the phylogenetic method, and the characteristic attribute organization system method. CONCLUSIONS: We demonstrated the utility of the TDEF reference barcode library to authenticate wood samples from timber operations in the TDEF. This pilot research study will enable more comprehensive surveys of the illegal timber trade of threatened species in the TDEF. This TDEF reference barcode library also contains trees that have medicinal properties, which could be used to monitor unsustainable and indiscriminate collection of plants from the wild for their medicinal value.