Ursolic acid, a naturally occurring 6-6-6-6-6 monohydroxy triterpenic acid, extractable from the leaves ofPlumeria rubra, spontaneously self-assemble in aqueous liquids yielding nanoarchitectures capable of entrapping guest molecules including anticancer drug.

The phytochemicals present in the stem bark extract of Nerium oleander (commonly known as Karabi) have been utilized for the green synthesis of stable gold-conjugated nanoparticles at room temperature under very mild conditions. The green synthesized gold-conjugated nanoparticles were characterized by surface plasmon resonance spectroscopy, High resolution transmission electron microscopy, X-ray diffraction studies and dynamic light scattering. A mechanism for the synthesis and stabilization of gold-conjugated nanoparticles (AuNPs) has been proposed. Anticancer activity of the stabilized AuNPs studied against MCF-7 breast cancer cell line revealed that the stabilized AuNPs were highly effective for the apoptosis of cancer cells selectively. The antioxidant activity of the stem bark extract of Nerium oleander has also been studied against a long lived 2,2-diphenylpicrylhydrazyl radical at room temperature. Moreover, the utilization of the stabilized AuNPs as a catalyst has also been demonstrated. Electronic supplementary materialThe online version of this article (10.1186/s40580-018-0142-5) contains supplementary material, which is available to authorized users.

Plant metabolites being renewable in nature have tremendous significance for the development of a sustainable society. In this manuscript we show that, terpenoids having nanometric lengths, commonly having several functional groups and several centers of chirality, can be utilized as renewable Molecular Functional Nanos (MFNs). The terpenoids spontaneously self-assembled in liquids yielding different morphologies such as vesicles, tubes, flowers, petals and fibers of nano- to micro-meter dimensions and supramolecular gels. The self-assemblies were utilized for the entrapment and release of fluorophores including anticancer drug, pollutant capture, generation of hybrid materials and catalysis.

Stigmasterol extracted from the leaves of Roscoea purpurea spontaneously self-assembled in liquids yielding a fibrillar network and gel.