Studies on the Diels-Alder adduct from cyclopentadiene and p-benzoquinone: Biotransformation, enantiomeric excess and absolute configuration

<div class="WordSection1"><p><em>The use of microorganisms or isolated enzymes in synthetic routes has been extensively used by industry and academic research. A great advantage of biotransformation in a synthetic route is highly regio- and enatiosselective control, which </em><em></em><em>can be achieved through microbial catalyzed reaction. Biotransformation is one of the most efficient methods in a production of high purity optical compounds and development of efficient routes for target molecules. Biotransformation by Mucor ramosissimus of enedione <strong>1</strong> gave the keto-alcohol <strong>(-)-2</strong> with enantiomeric excess (ee)&gt;99,9% (determined by ¹H NMR with [(+)-Eu(hfc)]₃) and their epimer<strong> (-)-3</strong>. Determination of the absolute configuration of epimer <strong>(-)-3</strong> was accomplished by controlled reaction and measuring of optical rotation (scheme 1). The fungus M. ramosissimus is a promising species to perform desymmetrization of diketones with high enantioselectivity. </em></p></div

Synthesis of 1,2,4 trioxolanes from vegetable oils for pharmaceutical and veterinary application

<p><em>Vegetable oils</em><em> are rich in mono-and poly-unsaturated fatty acids, and these compounds contain carbon-carbon double bonds available for chemical/structural modification, especially via oxidative processes. Sunflower oil obtained from seed of sunflower (</em><em>Helianthus annuus) contains a large amount of these acids, such as linoleic (48-74%) and oleic (14-39%) acids, proving to be an ideal starting material for these changes [1]. Ozone is an oxidizing agent that reacts with double bonds of fatty acids present in vegetable oils to form ozonides or 1,2,4 trioxolanes,  and peroxidic species such as hydroperoxides, hydrogen peroxide, polymeric peroxides and other organic peroxides. These compounds are of great pharmaceutical interest for the treatment of various dermatological diseases, due to their antimicrobial properties and stimulating action on tissue repair and regeneration [2]. In this work, the sunflower oil was ozonized, and the ideal conditions, as reaction time, ozone concentration and temperature, were determined. The IR and ¹H and ¹³C NMR of ozonized oils confirm the formation of 1,2,4 trioxolane ring according to the mechanism proposed by Criegee [3]. The ozonolysis reaction was performed under different conditions and the product is in the process of knowledge protection or patent</em><em>.</em></p

Synthesis of branched naphthoquinones from castor oil

<div class="WordSection1"><p><em>The naphthoquinones are cyclic aromatic α,β-dienonas with a basic framework derived from naphthalene. They are also found in many higher plants, algae, fungi and as the product of the  metabolism  of some  bacteria  having large biologica</em><em> activity described in the literature such as antibacterial, anti-inflammatory, antitumor, anticancer and trypanocidal [1-3]. Castor oil is an abundant raw material in Brazil of great versatility and, it is present in biodiesel production, surfactants, cosmetics and others. Considering the importance of naphthoquinones and, the availability of the ricinoleic acid from castor oil, the aim of this study was the preparation of new branched naphthoquinones in order to test their trypanocidal activity. Castor oil was submitted to saponification with sodium hydroxide, ethanol and water under reflux for 6 h. We then carried out an acid hydrolysis with hydrochloric acid and the formed ricinoleic acid was extracted with ethyl acetate. Following, through Kochi-Anderson addition reaction it was performed the alkylation of a naphthoquinone <strong>1</strong> and <strong>2</strong>, using ammonium persulfate, silver nitrate, acetonitrile and water, under heating at 70-80 ° C during 3 h, to give the branched naphthoquinones <strong>4</strong> and <strong>5</strong></em> <em>(scheme 1). The naphthoquinone <strong>3</strong> will be similarly submitted to this procedure. The naphthoquinones <strong>4</strong> and <strong>5</strong> were purified by column chromatography on sílica gel using hexane as the eluent. The compounds were characterized by mass spectrometry and ¹H and ¹³CNMR spectroscopy.</em></p></div

Oxidation of (+)-10β,14-Dihydroxy-allo-aromadendrane

molecule

Studies on the synthesis of new porphyrins from cardanol and glycerol

Porphyrins are very attractive compounds due to their wide application in many areas of new materials as chemical technology, ecology, medicine and, electronics. In the last years, they are also been a focus of attention owing to their implications to many photocatalytic reactions. Cardanol (isolated form cashew nut shell liquid) and glycerol (side product of biodiesel industry) are raw materials of low aggregated value; however, they hold chemical structures with functionalities that can lead to products of high commercial value to Brazilian industry. Aiming to use these chemical materials, our research group has proposed the synthesis of new hybrid molecular structures of porphyrin-cardanol-glycerol, which will be submitted to test of their photocatalytic properties. The synthetic proposal is based on the reaction of 4-hydroxybenzaldehyde (1) and epichloriridine (2) (derived from glycerol), using pyridine in dichloromethane and FeCl3 as a catalyst, under reflux and stirring. This process will provide the mixture of intermediate 3 and 4. These compounds will be attacked by the nucleophile cardanol (5) in sealed tube, using pyridine and dichloromethane at 120 ºC for 80 hours, giving the intermediate 6. After oxidation of the alcohol 6, the corresponding ketone will be achieved. Continuing the synthesis, these intermediates will separately react with pyrrol, giving the wished porphyrins that in turn will be transformed in macromolecules by treatment with Grubbs catalyst, according to methodologies already known in the literature. The previously synthesized compounds 3, 4, 5 and 6 had their structures confirmed by spectroscopy analyses of NMR (1H and 13C).</div

Synthesis and biological activity of sulfur compounds showing structural analogy with combretastatin A-4

We extended our previous exploration of sulfur bridges as bioisosteric replacements for atoms forming the bridge between the aromatic rings of combretastatin A-4. Employing coupling reactions between 5-iodo-1,2,3-trimethoxybenzene and substituted thiols, followed by oxidation to sulfones with m-CPBA, different locations for attaching the sulfur atom to ring A through the synthesis of nine compounds were examined. Antitubulin activity was performed with electrophoretically homogenous bovine brain tubulin, and activity occurred with the 1,2,3-trimethoxy-4-[(4-methoxyphenyl)thio]benzene (12), while the other compounds were inactive. The compounds were also tested for leishmanicidal activity using promastigote forms of Leishmania braziliensis (MHOM/BR175/M2904), and the greatest activity was observed with 1,2,3-trimethoxy-4-(phenylthio)benzene (10) and 1,2,3-trimethoxy-4-[(4-methoxyphenyl) sulfinyl]benzene (15)

Synthesis Method for Thiosulfonate and Report of Its Insecticidal Activity in Anagasta kuehniella (Lepidoptera: Pyralidae)

Abstract: Insect pests have caused economic losses valued at billions of dollars in agricultural production. Anagasta kuehniella (Zeller), the Mediterranean flour moth, is of major economic importance as a flour and grain feeder and is often a severe pest in flourmills. This study provides a suitable route for the direct preparation of thiosulfonates 2 and 3 from thiols, under mild conditions, with good yields; these thiosulfonates were tested for their regulatory effect on insect growth. The chronic ingestion of thiosulfonates resulted in a significant reduction in larval survival and weight. In addition, the tryptic activity of larvae was sensitive to these thiosulfonates. Results suggest that thiosulfonates 2 and 3 have a potential antimetabolic effect when ingested by A. kuehniella. The use of AgNO3/BF3·OEt2 and Al(H2PO4)3/HNO3 provides a suitable route for the direct preparation of thiosulfonates from thiols under mild conditions with good yields. These thiosulfonates were toxic for A. kuehniella larvae, suggesting their potential as biotechnological tools

Synthesis and evaluation of octocrylene-inspired compounds for UV-filter activity

Octocrylene (2-ethylhexyl 2-cyano-3,3-diphenyl-2-propenoate) is present in several sunscreens and is known to work synergistically with UV filters. We prepared eight octocrylene-related compounds to test their photoprotective activities by measuring diffuse transmittance. The compounds had varied photoprotection profiles, with Sun Protection Factors (SPF) ranging from 1 to 5 and UVA Protection Factors (UVAPF) ranging from 1 to 8. Compounds 4, 5, and 7 showed the best protection against UVB sunrays, while compounds 5, 6, and 7 presented the best results for protection from UVA, so compound 7 had the most balanced protection overall. Results for compounds 4, 8, and 9 are reported for the first time in the literature