ent-(15S)-Pimar-8(14)-ene-15,16-diol

The title compound {systematic name: (S)-1-[(2S,4aR,8aR)-2,4b,8,8-tetra­methyl-2,3,4,4a,4b,5,6,7,8,8a,9,10-dodeca­hydro­phenanthren-2-yl]ethane-1,2-diol}, C20H34O2, is an ent-pimarane diterpenoid which was isolated from the stem bark of Ceriops tagal. In the asymmetric unit, there are two crystallographically independent mol­ecules, which are conformationally almost identical. In each mol­ecule, the two cyclo­hexane rings of the fused three-ring system adopt chair conformations, while the cyclo­hexene ring is in an envelope conformation, with the methylene C atom next to the side chain as the flap atom. In the crystal, mol­ecules are stacked in columns along the b axis through O—H⋯O hydrogen bonds

Metal and metal oxide nanoparticles from Mimusops elengi Linn. Extract: green synthesis, antioxidant activity, and cytotoxicity

In this study, both silver (Ag) and zinc oxide (ZnO) nanoparticles are green synthesized using a water extract of the Mimusops elengi Linn. leaf. The methods are simple, inexpensive, nontoxic, and eco-friendly. The AgNPs and ZnONPs are formed using phytochemical substances in M. elengi leaf extract at room temperature. The phenolics and flavonoids in the leaf extract is the key compounds that act as the metal-reducing agents. The effective parameters of the green synthesis (the metal concentration, leaf extract concentration, pH, temperature, and reaction time) are evaluated. The formation of the metal and metal oxide nanoparticles (NPs) are confirmed through colour change visuals, ultraviolet–visible (UV-vis) spectroscopy (UV-vis), and Fourier transform infrared (FTIR) spectroscopy. The morphological and crystalline characterizations of the NPs are established using transmission electron microscopy (TEM) and X-ray diffraction (XRD). The TEM results indicated that the AgNPs are predominantly spherical in shape with an average particle size of 22.12 nm. The ZnONPs have mostly rod-like morphology with an average size of 28.44 nm. The antioxidant activity and cytotoxicity of the synthesized NPs against colon cancer cells (Caco-2 cells) are evaluated; the obtained NPs exhibited good free radical scavenging activity through DPPH, ABTS, and FRAP assays. The cytotoxicity results demonstrated that only the 2,000-ppm extract had any potential against the Caco-2 cells; both the AgNPs and ZnONPs had no effect on Caco-2 cells. However, regarding human health, metal NPs are safe to use and are useful in the other applications

องค์ประกอบทางเคมีจากผล ไฮโปคอทิลและเปลือกของโปรงแดง

Thesis (Ph.D., Organic Chemistry)--Prince of Songkla University, 200

A comparative study of stearyl aromatic esters and aromatic oil as processing aids in natural rubber compounds

Synthesized stearyl aromatic esters, namely stearyl benzoate, distearyl phthalate, stearyl biphenyl-4-carboxylate, and stearyl naphthoate, were used as processing aids for natural rubber compounding formulations. Their effects on curing and mechanical properties of natural rubber compounds were evaluated according to ASTM D3184. It was found that the aromatic esters enhanced curing characteristics in a similar way to aromatic oil which has been typically used in otherwise similar rubber formulations. Furthermore, the aromatic esters can slightly improve mechanical properties of natural rubber vulcanizates before aging. Although the mechanical properties of the vulcanizates in terms of tear strength, compression set, and thermal stability, deteriorated with aging, most useful properties were still on levels comparable to compounds with aromatic oil. Overall, stearyl aromatic esters may potentially in the future provide environmentally friendly alternatives to the use of aromatic oil, as processing aids for the rubber industry