The extent of adsorption (Γ2 1) of DNA from aqueous solution on different hydrophobic and hydrophilic solid surfaces has been compared as a function of pH, temperature, ionic strength of the medium, and denaturants. Γ2 1 at a given surface (except sephadex) increases with an increase of the nucleotide concentration (X 2) of DNA in mole fraction units, but it attains a monolayer saturation value Γ2 m when X 2 attains a value X 2 m . In most cases Γ2 1 increases further when X 2 ≫ X 2 m . Various neutral electrolytes like LiCl, KCl, CsCl, KBr, CaCl2, and Na2SO4, surfactants like SDS and Triton-X 100, the denaturing action of heat, and the addition of acid and alkali have been observed to play an important role during the study of the adsorption of DNA on charcoal powder. Further, a comparative study has been performed to examine the relative affinity of DNA toward different types of solid surfaces. The significant role of different types of surfaces in controlling the adsorption process has been explained in terms of Gibbs' surface excess quantities. The experimental results have been interpreted in terms of maximum work due to the free energy change of DNA adsorption on various solid surfaces and more quantitatively in terms of the standard free energy change (ΔG°) for the saturation of the surface by DNA as a result of the change in the nucleotide concentration in the bulk from zero to unity in mole fraction units.

The extent of adsorption (Γ2 1) of bovine serum albumin (BSA) and calf-thymus deoxyribonucleic acid (DNA) on the surface of casein has been studied as a function of pH, temperature, ionic strength of the medium, and denaturants. Γ2 1 in all cases increases with an increase of biopolymer concentration (X 2) in the bulk, and it attains a saturation value (Γ2 m ) when X 2 reaches X 2 m . In the case of DNA, Γ2 1 increases further with an increase of X 2 beyond the saturation value when X 2 reaches a critical value X 2 a. The influence of various inorganic electrolytes and denaturants on the extent of adsorption of BSA on casein has also been examined. Native DNA is not able to accumulate at the surface of casein in the presence of NaCl only, but with the addition of 1.0 × 10-3 M CaCl2 or 5.0 × 10-4 M AlCl3 the extent of adsorption increases to a significant amount. However, denatured DNA is able to do so in the sole presence of NaCl under identical solution conditions. The role of water in controlling the process of adsorption has been explained in terms of a Gibbs' surface excess quantity (Γ2 1).

Kemangi (Ocimum canum Sims L.) is one of the plants producing essential oils. Kemangi essential oil is taken from the stem and leaves. This study aims to determine the precentage of the yield of kemangi leaf oil and to identify the content of the chemical compounds of essential oils found in kemangi leaves based on the comparison of the place of growth and duration of distillation. Kemangi leaf samples were obtained from the Bontoala sub-district and from Tinggimoncong sub-district of South Sulawesi. The extraction method of essential oils of kemangi leaves is done by the method of distilation/hydrodestilation using three variations of distillation time, namely 6 hours, 12 hours and 18 hours. Based on the results of the study, it can be concluded that the kemangi leaf essential oil which has the highest yield is from Tinggimoncong sub-district of South Sulawesi, which is 3.325 % with distilation time for 18 hours, GC-MS identification results also show that kemangi leaves essential oil from Tinggimoncong sub

The Lamuru fish (Caranx ignobilis) is mostly found in tropical waters of the indo-pacific region, namely Indonesia. It is believed to contain collagen and this study aims to isolate collagen from its bone and determine the collagen’s antioxidant and α-glucosidase inhibitory activity. In our study, the collagen was extracted using acetic acid which was hydrolyzed by collagenase enzyme from Clostridium histolyticum at a temperature of 37 °C, and pH 7.0. During hydrolysis, the degree of hydrolysis (DH) was calculated and collagen hydrolysates were characterized by SDS -PAGE, UV-Visible spectroscopy and FT-IR spectroscopy. After characterization, the collagen hydrolisate of lamuru ( CHL) fish was analyzed for its antioxidant properties and α-glucosidase inhibitory activity. The result shows that a higher percentage degree of hydrolysis was obtained, 31.17%, at 120 min of hydrolysis. The CHL characterization by SDS -PAGE showed its molecular weight ranging from 35,000-180,000 Daltons and identified the collagen as type I. The UV-Vis analysis of CHL provided a maximum absorbance at a wavelength of 233 nm. At the same time, the FT-IR analysis showed the presence of amides I, II, and III, which confirms the formation of the collagen triple helix. For its bioactivity assay, the CHL shows that CHL provided DPPH radical reduction activity reaching 51.45±1.24% (IC50 at 485.9 µg/mL). The ferric reduction antioxidant power of CHL (FRAP value) showed a significant reduction of Fe3+ to Fe2+ with a value of 711.27 µM/g. The CHL inhibition activity of α-glucosidase enzyme IC50 was determined to be 574 µg/mL. Based on the antioxidant bioactivity and α-glucosidase inhibition, the collagen peptide enables its use as a therapeutic development for a variety of disorders caused by oxidative stress, such as diabetes mellitus.

One pot synthesis of acid esters by Stobbe condensation of alkylidene/ arylidene succinates and aldehydes or ketones, their subsequent hydrolysis of diacids and the formation of Tetralones and Indenones by different reagents are reported.