Stevia (Stevia rebaudiana) a bio-sweetener

Stevia has been used throughout the world since ancient times as a bio sweetener and as medicine in lower blood sugar. The leaves of Stevia plants have functional and sensory properties superior to those of many other high-potency sugars, Stevia is likely to become a major source of high-potency sweetener for the growing natural food market in the future. Although Stevia can be helpful to anyone, there are certain groups example- diabetic patients who are more likely to benefit from its remarkable sweetening potential. Its white crystalline compound (stevioside) is the natural herbal sweetener with no calories and is over 100-300 times sweeter than table sugar.

Antimicrobial Effects of a Lipophilic Fraction and Kaurenoic Acid Isolated from the Root Bark Extracts ofAnnona senegalensis

Root bark preparation ofAnnona senegalensisPers. (Annonaceae) is used in Nigerian ethnomedicine for treatment of infectious diseases. Extraction of theA. senegalensispowdered root bark with methanol-methylene chloride (1 : 1) mixture yielded the methanol-methylene extract (MME) which was fractionated to obtain the ethyl acetate fraction (EF). The EF on further fractionation gave two active subfractions, F1 and F2. The F1 yielded a lipophilic oily liquid while F2 on purification, precipitated white crystalline compound, AS2. F1 was analyzed using GC-MS, while AS2 was characterized by proton NMR and X-ray crystallography. Antibacterial and antifungal studies were performed using agar-well-diffusion method with 0.5 McFarland standard and MICs calculated. GC-MS gave 6 major constituents: kaur-16-en-19-oic acid; 1-dodecanol; 1-naphthalenemethanol; 6,6-dimethyl-bicyclo[3.1.1]hept-2-ene-2-ethanol; 3,3-dimethyl-2-(3-methylbuta-1,3-dienyl)cyclohexane-1-methanol; 3-hydroxyandrostan-17-carboxylic acid. AS2 was found to be kaur-16-en-19-oic acid. The MICs of EF, F1, and AS2 againstB. subtiliswere 180, 60, and 30 μg/mL, respectively. AS2 exhibited activity againstS. aureuswith an MIC of 150 μg/mL, while F1 was active againstP. aeruginosawith an MIC of 40 μg/mL. However, the extracts and AS2 exhibited no effects againstCandida albicansandAspergillus niger. Therefore, kaurenoic acid and the lipophilic fraction fromA. senegalensisroot bark exhibited potent antibacterial activity.

On two new compounds of chlorine and carbon, and on a new compound of iodine, carbon, and hydrogen

After some general observations respecting the action of chlorine upon compounds containing carbon, and more especially upon car-buretted hydrogen gas, Mr. Faraday details the processes by which he succeeded in obtaining two binary compounds of carbon and chlorine; the first, which he calls perchloride of carbon, was formed by exposing the triple compound of carbon, hydrogen, and chlorine, with excess of chlorine, to the agency of the direct solar rays; muriatic acid was formed, and a white crystalline compound at the same time generated. The author next describes the method of purifying this compound, and details its properties, which are briefly these:—it forms crystals, which appear to result from a primitive octahedron; it does not conduct electricity; it is slowly volatile, like camphor, at common temperatures, fusing at 320°, and boiling at 360°. It is not easily combustible; but when retained in the flame of the lamp; produces a red flame, with the formation of muriatic acid; it is insoluble in water, and readily soluble in alcohol, ether, and oils; and nearly insoluble in acids. When heated with several metallic peroxides it is decomposed with the production of carbonic acid, and a metallic perchloride. The author describes several experiments made with a view to ascertain the proportions in which the carbon and chlorine exist in this compound, from which it appears, that as one volume of olefiant gas requires five volumes of chlorine for its conversion into muriatic acid and this new chloride, and as four volumes of muriatic acid are formed, so three volumes of chlorine must unite to two of carbon to form the solid chloride.