Evaluation of triterpenes derivatives in the viability of Leishmania amazonensis and Trichomonas vaginalis

Trichomonas vaginalis and Leishmania spp. are protozoal species responsible for millions of cases of parasitic diseases worldwide. Considering the potential of natural products and the need for more effective and less toxic alternatives to treat trichomoniasis and leishmaniasis, this study aimed to evaluate the effect of two series of triterpenes derivatives with different modifications at C-3 and C-28 positions of the ursolic acid (UA) and betulinic acid (BA) against trophozoites of Trichomonas vaginalis and promastigotes forms of Leishmania (L.) amazonensis. The compounds modified just at C-3 were the most active. The 3β-acetyl betulinic acid (1b) reduced the trophozoites viability of T. vaginalis at 74%, followed by the 3-oxo ursolic acid and 3-oxo betulinic acid (3a and 3b) compounds (55% of reduction). The compound 3β-isobutyl ursolic acid (7a) inhibited the viability of L. amazonensis promastigotes by 55%. Therefore, analyzing the structure-activity relationship and the data of literature, it is possible to suppose that the inclusion of polar groups in the skeletons could improve the antiprotozoal activity. Overall, further studies are necessary to develop triterpenic derivatives with more powerful trichomonicidal and leishmanicidal properties.

Empleo de ultrasonido en la extracción de curcumina a partir de su fuente natural / Use of ultrasound in the extraction of curcumin from its natural source

INTRODUCCIÓN: Curcuma longa L. se comenzó a cultivar en Cuba en la década de los noventa del pasado siglo, a esta planta se le atribuyen propiedades anticancerígenas, antioxidantes, antibacterianas, entre otras. Su principio activo principal es la curcumina, un pigmento amarillo a partir del cual se pueden obtener diversos derivados de gran interés farmacológico. OBJETIVO: demostrar la factibilidad del uso de curcumina extraída de su fuente natural como precursor de fármacos. MÉTODOS: los rizomas de Curcuma longa L. fueron previamente tratados; después de estar secos, se pulverizaron y la extracción se realizó con metanol en un baño ultrasónico. El producto deseado (curcumina) se purificó por cromatografía de columna, para ser usado posteriormente como la materia de partida en la obtención de un análogo semisintético. Los compuestos aislados y sintetizados se caracterizaron por métodos espectroscópicos. RESULTADOS: se logró aislar curcumina con alto grado de pureza a partir de la Curcuma longa L. cultivada en Cuba, mediante un novedoso método de extracción asistido por ultrasonido. Se obtuvo y fue caracterizado un nuevo compuesto de gran interés farmacológico, a partir de la curcumina obtenida de materias primas nacionales. CONCLUSIONES: el empleo de ultrasonido hace más eficiente la extracción de la curcumina a partir de su fuente natural. Curcuma longa L. puede constituir una fuente de materias primas para la industria farmacéutica.

INTRODUCTION: cultivation of Curcuma longa L. in Cuba started in the 1990s. This plant has been attributed anticancer, antioxidant and antibacterial properties, among others. Its main active principle is curcumin, a yellow pigment from which various derivatives of great pharmacological interest may be obtained. OBJECTIVE: demonstrate the feasibility of the use of curcumin extracted from its natural source as a drug precursor. METHODS: Curcuma longa L. rhizomes were previously treated. Once dry, they were pulverized, and extraction was carried out with methanol in an ultrasonic bath. The desired product (curcumin) was purified by column chromatography to be used later on as the starting material to obtain a semisynthetic analogue. The isolated and synthesized compounds were characterized by spectroscopic methods. RESULTS: curcumin of a high degree of purity could be isolated from Curcuma longa L. cultivated in Cuba by means of a novel ultrasound-assisted extraction method. A new compound of great pharmacological interest was obtained and characterized, starting from curcumin obtained from national raw materials. CONCLUSIONS: ultrasound improves the efficiency of curcumin extraction from its natural source. Curcuma longa L. may constitute a source of raw materials for the pharmaceutical industry.

Hypericin: chemical synthesis and biosynthesis / 中国天然药物

Hypericin is one of the most important phenanthoperylene quinones extracted mainly from plants of the genus Hypericum belonging to the sections Euhypericum and Campylosporus of Keller's classification. Widespread attention to the antiviral and anti-tumor properties of hypericin has spurred investigations of the chemical synthesis and biosynthesis of this unique compound. However, the synthetic strategies are challenging for organic and biological chemists. In this review, specific significant advances in total synthesis, semi-synthesis, and biosynthesis in the past decades are summarized.

Progress in the chemical synthesis of artemisinin / 中国药学杂志

OBJECTIVE: To introduce the research progress in total-and semi-synthesis of artemisinin. METHODS: The review was based on representative literatures, and the data was summarized and analyzed. RESULTS AND CONCLUSION: Artemisinin is one of the most effective anti-malarial medicines. Since its discovery, artemisinin chemical synthesis has become a hot research topic. Nine total-synthesis methods andfive semi-synthesis methods were summarized, for which the overall yields were up to 10% and 60% respectively. Efficient synthesis of artemisinin in large scale by industry would be realized in the near future, and it will benefit hundred millions of patients.