This work describes the synthesis and determination of the sun protection factor (SPF) of sunscreen formulations containing two chemical filters obtained from vanillin. The syntheses yield reached 85% and 60% for obtaining the derivative 1 (4-(4hydroxy-3-methoxyphenyl)-3-buten-2-one) and derivative 2 (4-(4-acetyloxy-3methoxyphenyl)-3-buten-2-one), respectively. Formulations containing the chemical filters synthesized, at a concentration of 5.0%(w/w), showed UVB SPF in vitro equal to: derivative 1 (8.5 ± 0.2) and derivative 2 (12.2 ± 0.9). These values were higher than the formulation containing benzophenone-3 (6.9 ± 0.6) at the same concentration.

Exposure to ultraviolet radiation (UV) is the main factor related to skin cancer making the sunscreen an efficient prevention of this disease. Lapachol is a natural naphthoquinone found in some plant species which is capable of absorbing UV. Eight derivatives of lapachol were prepared by semi-synthesis and sun protection factors (SPF) against UVB radiation were determined using the spectrophotometric method developed by Mansur. The oximes derived from lapachol 5, 7, 8 and 9 showed significant photoprotective potential with SPF

Oxime is an organic functional group having the following general formula RR'C=N-OH and although its unquestionable importance in the Coordination Chemistry and Organic Synthesis it is a subject underexplored by main chemistry textbooks in higher education adopted in Brazil. Thus, this article is a review about oximes organized in three parts. First are shown the properties of the oximes with emphasis in its isomerism and behavior in solution. After, are discussed some methods for obtaining oximes, such as oximation of carbonyl groups and double bonds, oxidation of amines, reduction of nitro compounds and the radical. Finally, in the third part of the article are treated some synthetic routes of nitrogen functional groups where oximes are precursors. ResumoOxima é u g upo fu io al o g i o ue ap ese ta a fó ula ge al RR'C=N-OH e apesar da sua relevância inquestionável na Química das Coordenações e na Síntese Orgânica este é um tema pouco explorado pelos principais livros de Química de ensino superior adotados no Brasil. Desta forma, o presente artigo trata de uma revisão sobre oximas, que está organizado em três partes. Inicialmente são mostradas as propriedades das oximas dando ênfase a sua isomeria e comportamento em solução. Em seguida, são abordadas algumas metodologias para a obtenção de oximas, como: oximação de carbonilas e duplas ligações, oxidação de aminas, redução de nitrocompostos e por via radicalar. Por fim, na terceira parte do artigo são tratadas algumas vias de síntese de grupos funcionais nitrogenados onde oximas são precursoras. Palavras-chave:Oxima; Propriedades Químicas das Oximas;