4 research outputs found
4âQuinolone Alkaloids from <i>Melochia odorata</i>
The methanol extract of <i>Melochia
odorata</i> yielded three 4-quinolone alkaloids including waltherione
A (<b>1</b>) and two new alkaloids, waltherione C (<b>2</b>) and waltherione D (<b>3</b>). Waltheriones A and C showed
significant activities in an in vitro anti-HIV cytoprotection assay
at concentrations of 56.2 and 0.84 ÎŒM and inhibition of HIV
P24 formation of more than 50% at 1.7 and 0.95 ÎŒM, respectively.
The structures of the alkaloids were established by spectroscopic
data interpretation
New Guinea has the worldâs richest island flora
New Guinea is the world's largest tropical island and has fascinated naturalists for centuries1,2. Home to some of the best-preserved ecosystems on the planet3 and to intact ecological gradients-from mangroves to tropical alpine grasslands-that are unmatched in the Asia-Pacific region4,5, it is a globally recognized centre of biological and cultural diversity6,7. So far, however, there has been no attempt to critically catalogue the entire vascular plant diversity of New Guinea. Here we present the first, to our knowledge, expert-verified checklist of the vascular plants of mainland New Guinea and surrounding islands. Our publicly available checklist includes 13,634 species (68% endemic), 1,742 genera and 264 families-suggesting that New Guinea is the most floristically diverse island in the world. Expert knowledge is essential for building checklists in the digital era: reliance on online taxonomic resources alone would have inflated species counts by 22%. Species discovery shows no sign of levelling off, and we discuss steps to accelerate botanical research in the 'Last Unknown
New Guinea has the worldâs richest island flora
New Guinea is the worldâs largest tropical island and has fascinated naturalists for centuries1,2. Home to some of the best-preserved ecosystems on the planet3 and to intact ecological gradientsâfrom mangroves to tropical alpine grasslandsâthat are unmatched in the Asia-Pacific region4,5, it is a globally recognized centre of biological and cultural diversity6,7. So far, however, there has been no attempt to critically catalogue the entire vascular plant diversity of New Guinea. Here we present the first, to our knowledge, expert-verified checklist of the vascular plants of mainland New Guinea and surrounding islands. Our publicly available checklist includes 13,634 species (68% endemic), 1,742 genera and 264 familiesâsuggesting that New Guinea is the most floristically diverse island in the world. Expert knowledge is essential for building checklists in the digital era: reliance on online taxonomic resources alone would have inflated species counts by 22%. Species discovery shows no sign of levelling off, and we discuss steps to accelerate botanical research in the âLast Unknownâ8