Natural surfactants or biosurfactants are amphiphilic biological compounds, usually extracellular, produced by a variety of microorganisms from various substances including waste materials. There is increasing interest on this topic because of their unique properties such as low toxicity, functionality under extreme conditions, based on renewable substances and biologically degradable nature. The diversity of these molecules supports their potential application in the field of petroleum, medicine, agriculture, food, cosmetics etc. They are also effective in curtailing the green-house effect by reducing the emission of CO₂. They can be termed as ‘green’ because of their low toxicity, biodegradability and relative stability under a wide range of physicochemical environments. In spite of possessing diverse structures and better physicochemical properties than chemical surfactants, biosurfactants are not able to compete with their synthetic counterparts because of their high production & downstream costs. The commercial realization of these eco-friendly biomolecules is restricted by low productivity, expensive downstream processing and lack of appropriate understanding of the bioreactor systems for their production. But we expect that in future better reactor design and product recovery technology would be developed and overproducer microbial strain would be screened. Then production cost would be decreased and yield would be increased i.e. the production would be both ecologically & economically favored. The present review deals with an overall view on biosurfactants, their properties, advantages & disadvantages, production, characterization, application along with a recommendation for future research.

A new synthetic method for obtaining [RhCl(cod)(NHC)] complexes (1–4) (cod = η⁴-1,5-cyclooctadiene, NHC = N-heterocyclic carbene: IMes, SIMes, IPr, and SIPr, respectively) is reported together with the catalytic properties of 1–4 in nitrile hydration. In addition to the characterization of 1–4 in solution by ¹³C NMR spectroscopy, the structures of complexes 3, and 4 have been established also in the solid state with single-crystal X-ray diffraction analysis. The Rh(I)-NHC complexes displayed excellent catalytic activity in hydration of aromatic nitriles (up to TOF = 276 h⁻¹) in water/2-propanol (1/1 v/v) mixtures in air.

Bio-inorganic nanoparticles or metal nanoparticles are used in medicine for diagnostic and treatment purposes. The nanomedicines from traditional Ayurvedic system are termed as bhasma. Rasashastra, the branch of inorganic medicines of Ayurveda, has documented monographs of metal-mineral bhasmas as potent drugs. However there is lack of scientific analytical data of the end products. Present study was aimed at finding out the morphological, structural, elemental and chemical composition of the Krishna vajra abhraka bhasma (KVB). Bhasma of KVB (Biotite Mica) was prepared in our laboratory using biotite mica sheets befitting selection criteria and carrying out further processes with strict SOPs as per AFI. The bhasma complied with the confirmatory tests from Rasashastra. The physical and physicochemical tests correlate with the results obtained by instrumental analytical methods. SEM revealed square shaped nanoparticles of mean size of 92.3 nm. EDAX showed presence of Si, Mg, O, Fe, Ca, Na, C, K and Al. XRD revealed the crystalline nature of bhasma with mixture of various individual oxides and spinel shape of the crystal. DLS showed that the nanoparticles are unimodal in nature. FTIR and NMR showed the organic functional groups obtained from cow milk and selected herbs, indicating unique bio-inorganic nature of the KVB. The therapeutic potential imparted to the formulation could be due to the cow milk and specific herbs utilized during the manufacturing process.