A study of the anthocyanins of kenaf
Continuing a study of the anthoeyanins [1] of the family Malvaceae , by par t i t ion chromatography on a column of ce l lu lose powder [in the w a t e r a c e t i c acid (85 : 15) system] we have isolated f rom the f lowers of Hibiscus cannabinus var . s implex (kenaf) col lected in the expe r imen ta l sect ion of the cent ra l Asian Branch of VIR ]All-Union Scientif ic R e s e a r c h Inst i tute for Plant Breeding] an anthocyanin with mp 164-166 ° C (decomp.) having the composi t ion C26H29016C 1.4H20.
Phytochemicals and antioxidant activity in the kenaf plant ( Hibiscus cannabinus L.)
This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Chemical compounds from four different tissues of the kenaf plant (Hibiscus cannabinus), a valuable medicinal crop originating from Africa, were examined to determine its potential for use as a new drug material. Leaves, bark, flowers, and seeds were harvested to identify phytochemical compounds and measure antioxidant activities. Gas chromatography mass spectrometry analyses identified 22 different phytocompounds in hexane extracts of the different parts of the kenaf plant. The most abundant volatile compounds were E-phytol (32.4%), linolenic acid (47.3%), trisiloxane-1,1,1,5,5,5-hexamethyl3,3-bis[(trimethylsilyl)oxy] (16.4%), and linoleic acid (46.4%) in leaves, bark, flowers, and seeds, respectively. Ultra-high performance liquid chromatography identified the major compounds in the different parts of the kenaf plant as kaemperitrin, caffeic acid, myricetin glycoside, and p-hydroxybenzoic acid in leaves, bark, flowers, and seeds, respectively. Water extracts of flowers, leaves, and seeds exhibited the greatest DPPH radical scavenging activity and SOD activity. Our analyses suggest that water is the optimal solvent, as it extracted the greatest quantity of functional compounds with the highest levels of antioxidant activity. These results provide valuable information for the development of environmentally friendly natural products for the pharmaceutical industry.
Control of the homopause level
Abstract This paper reviews the hypothesis that internal gravity wave breaking in the factor responsible for upper atmosphere turbulence generation and control of the number density at the homopause level. Available data from Mars and Earth support the hypothesis, originally introduced by Lindzen, that breaking thermal tides are responsible for the necessary turbulence. The lowest-order, equatorially trapped, westward-propagating diurnal tidal mode is the primary cause on the Earth, and lower-order westward-propagating semidiurnal modes are the primary cause on Mars. The frequencies and vertical wavenumbers of the responsible modes determine the eddy diffusion coefficients; energy density is only indirectly involved by determining which modes can break. A general scale relationship between tidal heating and velocity amplitude can be used to assess the breaking potential of tidal modes, and is used here as the basis for arguing that the number density at the Martian homopause is likely to have been stable over much of geologic time. Difficulties with this approach arise in the cases of Venus and Titan because of their peculiar zonal winds. For Jupiter and Saturn, internal gravity waves generated by nontidal mechanisms probably control the homopause.