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We describe the enzymatic synthesis of biodiesel from waste cooking oil (WCO) in a two-step production process: hydrolysis of WCO, followed by acid-catalyzed esterification of free fatty acids (FFAs). Among the three commercial enzymes evaluated, the inexpensive lipase Lipex® 100L supported on Lewatit® VP OC 1600 produced the best overall biodiesel yield (96.3%). Finally, we assessed the combustion efficiency of the obtained biodiesel and its blends. All blends tested presented lower emissions of CO and HC compared to diesel. The NOx emissions were higher due to biodiesel's high volatility and viscosity. The cost of biodiesel production was calculated using the process described.

Enzyme catalyzed synthesis is an eco-friendly technique in organic synthesis, having several benefits over conventional methods. In the present work, we describe a simple process of laccase and chloroperoxidase assisted cyclization of chalcones, leading to the formation of flavanones. The reaction proceeds in a mixture of phosphate buffer and ethanol, under oxygen atmosphere at room temperature, yielding the corresponding flavanone in good to moderate yield. The relative configuration of the products at C2 is tentatively assigned as S*-flavanone based on the coupling constants with the methylenic protons H3α,β. In comparison to the chemical methods, we describe a process which can be achieved efficiently under mild conditions using oxygen as oxidant.

Syringodium filiforme Kützing (Cymodoceaceae) is a marine seagrass abundant in Caribbean Sea, rich in phenolic compounds which have antioxidant properties and can provide new opportunities for treatment and prevention of diseases mediated by ultraviolet radiation like photoaging and skin cancer. The aim of this study was to evaluate the phytochemical profile and the photoprotective potential of S. filiforme leaf extracts . Total phenolic and flavonoid contents were 72.85 ± 0.72 mg pyrogallol equivalents/g dry extract (PE) and 59.09 ± 0.45 mg quercetin equivalents/g dry extract (QE), respectively. The total anthocyanins content was 1.35 ± 0.02 mg malvidin-3-O-glucoside equivalents/g dry extract (ME). The extract showed photoprotector potential in the UVB region. The S. filiforme treated mice showed a significantly decreased wrinkling score, and a reorganization of the collagen fiber was observed compared with irradiated and not treated skin. These results suggest that the crude extract of S. filiforme leaves may be a promising natural sunscreen product.

The available scientific literature regarding tanshinones is very abundant, and after its review, it is noticeable that most of the articles focus on the properties of tanshinone I, cryptotanshinone, tanshinone IIA, sodium tanshinone IIA sulfonate and the dried root extract of Salvia miltiorrhiza (Tan- Shen). However, although these products have demonstrated important biological properties in both in vitro and in vivo models, their poor solubility and bioavailability have limited their clinical applications. For these reasons, many studies have focused on the search for new pharmaceutical formulations for tanshinones, as well as the synthesis of new derivatives that improve their biological properties. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2015) on tanshinones in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we offer an update on the last five years of new research on these quinones, focusing on their synthesis, biological activity on noncommunicable diseases and drug delivery systems, to support future research on its clinical applications.

Carnosic Acid (CA) and its major oxidized derivative, carnosol, are phenolic abietane diterpenes present in various species of the Lamiaceae family, such as Salvia and Rosmarinus .

In the current study, chemical composition of cultivated Salvia canariensis L was determined. Carnosol was the main product isolated. We prepared more lipophilic derivatives from carnosol, and both isolated and semisynthetic abietane diterpenes were evaluated in vitro as inhibitors of squalene synthase. Among the compounds tested, carnosol was the most potent inhibitor (IC50 = 17.6 μM). These results highlight the great potential of this species for the production of new ingredients in nutritional supplements for the treatment of hyperlipidemia.

Covering: 2000 to 2014 This review highlights the broad range of science that has arisen from the synthesis of coumarin-linked and fused heterocycle derivatives. Specific topics include their synthesis and biological activity.

The crystal structure together with unambiguous assignation of 1H and 13C NMR signals of 3-epismilagenin acetate 4 and 23-oxo-3-epismilagenin acetate 5 are described. Compound 4, crystallized as orthorhombic system a = 10.535(1) A, b = 13.775 (1) A, c = 18.347 (1) A, α = β = γ = 90°; with space group P2 1 2 1 2 1 ; while compound 5 crystallized as a monoclinic system a = 10.380(1) A, b = 7.327(1) A, c = 17.881(1) A, α = γ = 90°, β = 99.56(1)°, with a space group P2 1 . The presence a carbonyl group at C(23) in compound 5 produces a significant deviation from the chair conformation observed in compound 4. The effects of the side chain modifications on the puckering parameters derived from are discussed. The crystal structure, together with unambiguous assignation of 1H and 13C NMR signals of two epismilagenin acetates, is described.

The full assignments of the 1H and 13C NMR signals of steroids bearing the 16β,23:23,26-diepoxy side chain are provided. Differentiation of the diasterotopic H-26 pair was achieved with the aid of NOESY experiments. The main substituent and steric effects associated with this moiety and their influence on the chemical shifts of the neighboring atoms are discussed.

Covering: 2000 to 2014 This review highlights the broad range of science that has arisen from the synthesis of coumarin-linked and fused heterocycle derivatives. Specific topics include their synthesis and biological activity.

F-ring opening in spirostanes with the 16β,22:22,25-diepoxy-23-acetoxymethyl-24-methyl side chain produces a Δ22-intermediate with an allylic acetoxy group. For this reason the reactivity profile of these compounds deviates from that observed in other naturally occurring or synthetic spirostanes and furospirostanes

Brønsted and Lewis acid-catalysed reactions of the 23-methoxycarbonyl furospirostanic side chain are described. While bromination, deuteration and BF(3)·Et(2)O/AcOH treatment involve regioselective F-ring opening with exclusive participation of Δ(22)-furostenic intermediates, BF(3)·Et(2)O/Ac(2)O treatment leads to irreversible E- or F-ring cleavage.

During reactions of 23-oxosapogenins and the corresponding isomeric 22-oxo-23-spiroketals with MCPBA in the presence of BF(3)·Et(2)O, equilibration occurs between the ketones. The Baeyer-Villiger type oxidation is followed by fragmentation to the dinorcholanic lactones and 3-methylbutyrolactone. The mechanistic aspects of these reactions in the 25R and 25S series are discussed.

The Beckmann rearrangement of the syn and anti isomers of the spirocyclic oxime derived from a 16beta,23:23,26-diepoxy-5beta-cholestan-22-one was studied. Whereas the anti isomer always follows the Beckmann fragmentation course, the syn isomer, depending on the reaction conditions, follows the normal Beckmann rearrangement course and/or the isomerization to the anti isomer followed by the fragmentation course.

The full assignments of the (1)H and (13)C NMR signals of steroids bearing the 16beta,23:23,26-diepoxy side chain are provided. Differentiation of the diasterotopic H-26 pair was achieved with the aid of NOESY experiments. The main substituent and steric effects associated with this moiety and their influence on the chemical shifts of the neighboring atoms are discussed.

The synthesis and assignment of 1 H and 13 C NMR signals and X-Ray characterization of steroids bearing furospirostane side chains is provided. The effects of the side chain modifications on the puckering parameters and NMR characteristics derived from the modification of the side chains are discussed.