The Experts below are selected from a list of 738 Experts worldwide ranked by ideXlab platform
Khanit Suwanborirux - One of the best experts on this subject based on the ideXlab platform.
-
Marine Compounds as Sources of Chemotherapeutics
2010Co-Authors: Khanit SuwanboriruxAbstract:Marine organisms have been recognized as a source for new anticancer natural products since the availability of ara-C, a sponge-derived nucleoside, for the treatment of acute myeloid leukemia and non-Hodgkin’s lymphoma. Later, searches for new marinederived compounds have been world widely explored to develop potential anticancer agents such as dolastatins, bryostatins, didemnins, aplidins, kalahalides, and ecteinascidins. In this presentation, we also discuss the investigation of two highly cytotoxic tetrahydroisoquinoline alkaloids, including renieramycins and ecteinascidins from the Thai sponge Xestospongia sp. and the Thai ascidian Ecteinascidia thurstoni, respectively. With large quantities of these natural products in hand, chemical transformations and the structurecytoxicity relationships of these compounds have been studied for further development of these cytotoxic alkaloids as new anticancer agents from in-the-sea farming Thai marine organisms.
-
chemistry of renieramycins part 7 renieramycins t and u novel renieramycin ecteinascidin hybrid marine natural products from thai sponge xestospongia sp
Tetrahedron Letters, 2009Co-Authors: Naomi Daikuhara, Surattana Amnuoypol, Khanit Suwanborirux, Yumiko Tada, Sachiyo Yamaki, Kornvika Charupant, Naoki SaitoAbstract:Abstract Two new bistetrahydroisoquinoline marine natural products, renieramycins T ( 1 ) and U ( 2 ), were isolated from the Thai blue sponge Xestospongia sp. and their structures were elucidated by comparing spectral data with those of renieramycin M ( 3a ) and ecteinascidin 770 ( 4a ). These compounds are the first reported examples of novel ecteinascidin–renieramycin hybrid natural products. Renieramycin T ( 1 ) showed strong cytotoxicity to several human cancer cell lines, its IC 50 values ranging from 4.7 to 98 nM.
-
Two introduced tunicate species, Ecteinascidia thurstoni Herdman, 1891 and Clavelina cyclus Tokioka & Nishikawa, 1975, in Thailand
Aquatic Invasions, 2009Co-Authors: Suchana Chavanich, Khanit Suwanborirux, Voranop Viyakarn, Somkiat Piyatiratitivorakul, Somchai BussarawitAbstract:Recently, two introduced tunicate species Ecteinascidia thurstoni Herdman, 1891 and Clavelina cyclus Tokioka & Nishikawa, 1975 were discovered in the coastal waters of Thailand. E. thurstoni was found in Andaman Sea, the west coast of Thailand while C. cyclus was first recorded in the east coast, upper Gulf of Thailand. From the historical records, E. thurstoni can be found in South Asia, South Africa, Australia, and Red Sea while C. cyclus can be found in the tropical Indo-West Pacific.
-
two introduced tunicate species Ecteinascidia thurstoni herdman 1891 and clavelina cyclus tokioka nishikawa 1975 in thailand
Aquatic Invasions, 2009Co-Authors: Suchana Chavanich, Khanit Suwanborirux, Voranop Viyakarn, Somkiat Piyatiratitivorakul, Somchai BussarawitAbstract:Recently, two introduced tunicate species Ecteinascidia thurstoni Herdman, 1891 and Clavelina cyclus Tokioka & Nishikawa, 1975 were discovered in the coastal waters of Thailand. E. thurstoni was found in Andaman Sea, the west coast of Thailand while C. cyclus was first recorded in the east coast, upper Gulf of Thailand. From the historical records, E. thurstoni can be found in South Asia, South Africa, Australia, and Red Sea while C. cyclus can be found in the tropical Indo-West Pacific.
-
Chemistry of ecteinascidins. Part 2. Preparation of 6'-O-acyl derivatives of stable ecteinascidin and evaluation of cytotoxicity.
Chemical & pharmaceutical bulletin, 2006Co-Authors: Ploenthip Puthongking, Akinori Kubo, Chamnan Patarapanich, Surattana Amnuoypol, Khanit Suwanborirux, Naoki SaitoAbstract:A large amount of stable ecteinascidin 770 (1b) was isolated from the Thai tunicate, Ecteinascidia thurstoni, which was pretreated with potassium cyanide in buffer solution (pH 7), along with a minor metabolite, ecteinascidin 786 (1c). A number of 6′-O-acyl derivatives 3—19 and three diacetyl derivatives 2a—c of the stable 1b were prepared and evaluated for activity against human tumor cell lines HCT116, QG56, and DU145. Nitrogen-containing heterocyclic ester derivatives such as 12, 13, and 16—19 showed similar in vitro cytotoxicity to 1b, whereas the other derivatives were less cytotoxic than 1b. Furthermore, we discovered that the N-indole-3-carbonyl derivative of ecteinascidin 770 (22) has higher cytotoxicity than 1b.
Naoki Saito - One of the best experts on this subject based on the ideXlab platform.
-
Stereoselective Total Synthesis of (−)-Renieramycin T
2016Co-Authors: Masashi Yokoya, Robert M. Williams, Ryoko Toyoshima, Toshihiro Suzuki, Naoki SaitoAbstract:A stereoselective total synthesis of (−)-Renieramycin T (1t) from a key tetrahydroisoquinoline intermediate previously utilized in our formal total synthesis of Ecteinascidin 743 is described. The synthesis features a concise approach for construction of the pentacyclic framework using a Pictet–Spengler cyclization of bromo-substituted carbinolamine 17, which obviates the regioselectivity problem of the Pictet–Spengler cyclization. The results of cytotoxicity studies are also presented
-
chemistry of renieramycins part 7 renieramycins t and u novel renieramycin ecteinascidin hybrid marine natural products from thai sponge xestospongia sp
Tetrahedron Letters, 2009Co-Authors: Naomi Daikuhara, Surattana Amnuoypol, Khanit Suwanborirux, Yumiko Tada, Sachiyo Yamaki, Kornvika Charupant, Naoki SaitoAbstract:Abstract Two new bistetrahydroisoquinoline marine natural products, renieramycins T ( 1 ) and U ( 2 ), were isolated from the Thai blue sponge Xestospongia sp. and their structures were elucidated by comparing spectral data with those of renieramycin M ( 3a ) and ecteinascidin 770 ( 4a ). These compounds are the first reported examples of novel ecteinascidin–renieramycin hybrid natural products. Renieramycin T ( 1 ) showed strong cytotoxicity to several human cancer cell lines, its IC 50 values ranging from 4.7 to 98 nM.
-
Chemistry of ecteinascidins. Part 2. Preparation of 6'-O-acyl derivatives of stable ecteinascidin and evaluation of cytotoxicity.
Chemical & pharmaceutical bulletin, 2006Co-Authors: Ploenthip Puthongking, Akinori Kubo, Chamnan Patarapanich, Surattana Amnuoypol, Khanit Suwanborirux, Naoki SaitoAbstract:A large amount of stable ecteinascidin 770 (1b) was isolated from the Thai tunicate, Ecteinascidia thurstoni, which was pretreated with potassium cyanide in buffer solution (pH 7), along with a minor metabolite, ecteinascidin 786 (1c). A number of 6′-O-acyl derivatives 3—19 and three diacetyl derivatives 2a—c of the stable 1b were prepared and evaluated for activity against human tumor cell lines HCT116, QG56, and DU145. Nitrogen-containing heterocyclic ester derivatives such as 12, 13, and 16—19 showed similar in vitro cytotoxicity to 1b, whereas the other derivatives were less cytotoxic than 1b. Furthermore, we discovered that the N-indole-3-carbonyl derivative of ecteinascidin 770 (22) has higher cytotoxicity than 1b.
-
Ecteinascidins 770 and 786 from the Thai tunicate Ecteinascidia thurstoni.
Journal of natural products, 2002Co-Authors: Khanit Suwanborirux, Surattana Amnuoypol, Kornvika Charupant, Sunibhond Pummangura, And Akinori Kubo, Naoki SaitoAbstract:Ecteinascidins 770 (1b) and 786 (3b) were isolated from the pretreated Thai tunicate Ecteinascidia thurstoni with potassium cyanide in buffer solution (pH 7). These structures were fully elucidated by extensive 2D NMR analysis.
-
A practical synthesis of the ABC ring model of ecteinascidins.
CHEMICAL & PHARMACEUTICAL BULLETIN, 2000Co-Authors: Naoki Saito, Masashi Tachi, Ryu-ichi Seki, Hiroshi Kamayachi, Akinori KuboAbstract:A practical synthesis of 1,2,3,4,5,6-hexahydro-1,5-imino-10-hydroxy-9-methoxy-3,8,11-trimethyl-3- benzazocin-4-one (3) as an ABC ring model compound of ecteinascidin 743 and safracins from 3-hydroxy-4-methoxy-5-methylbenzaldehyde (7) is described. The overall yield in 15 steps is 27%.
Somchai Bussarawit - One of the best experts on this subject based on the ideXlab platform.
-
Two introduced tunicate species, Ecteinascidia thurstoni Herdman, 1891 and Clavelina cyclus Tokioka & Nishikawa, 1975, in Thailand
Aquatic Invasions, 2009Co-Authors: Suchana Chavanich, Khanit Suwanborirux, Voranop Viyakarn, Somkiat Piyatiratitivorakul, Somchai BussarawitAbstract:Recently, two introduced tunicate species Ecteinascidia thurstoni Herdman, 1891 and Clavelina cyclus Tokioka & Nishikawa, 1975 were discovered in the coastal waters of Thailand. E. thurstoni was found in Andaman Sea, the west coast of Thailand while C. cyclus was first recorded in the east coast, upper Gulf of Thailand. From the historical records, E. thurstoni can be found in South Asia, South Africa, Australia, and Red Sea while C. cyclus can be found in the tropical Indo-West Pacific.
-
two introduced tunicate species Ecteinascidia thurstoni herdman 1891 and clavelina cyclus tokioka nishikawa 1975 in thailand
Aquatic Invasions, 2009Co-Authors: Suchana Chavanich, Khanit Suwanborirux, Voranop Viyakarn, Somkiat Piyatiratitivorakul, Somchai BussarawitAbstract:Recently, two introduced tunicate species Ecteinascidia thurstoni Herdman, 1891 and Clavelina cyclus Tokioka & Nishikawa, 1975 were discovered in the coastal waters of Thailand. E. thurstoni was found in Andaman Sea, the west coast of Thailand while C. cyclus was first recorded in the east coast, upper Gulf of Thailand. From the historical records, E. thurstoni can be found in South Asia, South Africa, Australia, and Red Sea while C. cyclus can be found in the tropical Indo-West Pacific.
José Luis Carballo - One of the best experts on this subject based on the ideXlab platform.
-
Production of Ecteinascidia turbinata (Ascidiacea: Perophoridae) for Obtaining Anticancer Compounds
Journal of the World Aquaculture Society, 2007Co-Authors: José Luis Carballo, Santiago Naranjo, Bulent Kukurtzü, Fernando De La Calle, Aida Hernández-zanuyAbstract:Two methods have been tested in order to produce large quantities of Ecteinascidia turbinata for the extraction of anti-tumoral substances. With the first method, the capacity of generating biomass from settlement of larvae in a natural environment was estimated. The second method consisted of fragmenting colonies into small pieces, which were transplanted onto plastic screen where partial periodic collections of the colony could be carried out. For the first method, two different artificial substrates for settlement of larvae were studied: lines composed of hanging strips of wood, and plastic cords. The average production per unit of surface was significantly different between the two artificial substrates (P < 0.005) (4.25 kg/M2 on the wooden strips after 75 days versus 1.39 kg/m2 on the plastic cords after 80 d). The transplant experiment showed a 93% survival of the colony 26 d after the colonies were transplanted and settled, and 96.48 kg of average biomass were collected, indicating a 235% increase in biomass. This system permits stolonial regrowth of the biomass fixed on the surface, without new transplants or settlements being needed, so that a continuous production can be maintained. The fragmentation of the colonies stimulate genet growth rates through the production of small daughter colonies which individually have higher relative growth rates than large colonies and, therefore, collectively have higher absolute growth rates than a large colony of similar biomass. The production of E. turbinata using a combination of the two methods is an example of successful production of metabolites from marine organisms while protecting natural populations.
-
Distribución y abundancia de la ascidia Ecteinascidia turbinata (Ascidiacea: Perophoridae) en Cuba
Vicerractoría Investigación, 2007Co-Authors: Aida Hernández-zanuy, Santiago Naranjo, José Luis Carballo, Alida García-cagide, Macario EsquivelAbstract:Ecteinascidia turbinata está ampliamente distribuida en las áreas de mangle rojo (Rhizophora mangle) de tipo sobrelavados donde ocupa la porción permanentemente sumergida. Ocasionalmente se encontró sobre el coral negro Antipathes caribeana a 22 y 38 m de profundidad. Sin embargo no fue frecuente en los manglares de borde ni de ribera. Se muestrearon 58 localidades estando presente la especie en un 75 % de las mismas. Sus poblaciones son abundantes pues en el 57 % de las zonas prospectadas más del 25 % de las raíces del manglar poseen al menos una colonia. Las mayores densidades se encontraron en la costa noroeste de Cuba (Pinar del Río) con valores cercanos a una colonia por metro lineal de manglar, siendo Cayo Jutías la de mayor densidad (1.46 col/m). La mayor biomasa también se registró en la mencionada localidad con valores comprendidos entre 25 y 660 g/m lineal de manglar. El promedio general de la biomasa en los manglares estudiados fue de 73.63 g/m lineal de manglar.Distribution and abundance of the ascidian Ecteinascidia turbinata (Ascidiacea: Perophoridae) in Cuba. Permanently submerged mangrove roots (Rhizophora mangle) are the main habitat of the ascidian Ecteinascidia turbinata in Cuba. It was occasionally found on black coral (Antiphates caribeana) between 22 and 38 meters deep. This species exhibits a wide distribution in all the mangrove keys surrounding the Island of Cuba but does not occur in riparian or fringing mangroves. Populations of this species are abundant in Cuba: in 75 % of the 58 localities sampled the species was present and in 57 % more than 50 % of the roots held at least one colony. The highest colony densities were found in the northern coast of Pinar del Río province with values near one colony per lineal meter of mangrove root. We found the highest density (1.46 col/m) and greatest biomass at Jutías Key, with values between 25 and 660 g/m. The average of wet biomass in the studied mangroves was 73.63 g/m. Rev. Biol. Trop. 55 (1): 247-254. Epub 2007 March. 31
-
Alimentación de la ascidia Ecteinascidia turbinata (Ascidiacea: Perophoridae) en dos áreas de manglar de Cuba
Vicerractoría Investigación, 2007Co-Authors: Aida Hernández-zanuy, Alida García-cagide, Nilda Borrero, José Luis CarballoAbstract:Se estudiaron los contenidos estomacales de 88 zooides de Ecteinascidia turbinata Herdman 1880 y la composición cualitativa y cuantitativa del fitoplancton en la columna de agua en Santa Fe (Litoral Norte de la Habana) y Punta del Este (SW de Cuba). En el contenido estomacal de la ascidia se identificaron 59 especies de microalgas y cuatro tintínidos. El tamaño de las células varió entre 75 y 165 µm de largo y de 2 a 105 µm de ancho. No se encontraron diferencias significativas en la diversidad de especies de microalgas en la columna de agua de las dos localidades. Las diatomeas tuvieron la mayor cantidad de especies y el mayor número de individuos, tanto en los estómagos como en la columna de agua en ambas localidades. La biomasa de dinoflagelados en Santa Fe fue mayor en agua y estómagos. En Punta del Este el aporte de cada grupo al contenido estomacal es similar al encontrado en la columna de agua. Esta especie filtra de forma constante e irregular durante las 24 horas del día, independientemente de la disponibilidad de alimento.Diet of the ascidian Ecteinascidia turbinata (Ascidiacea: Perophoridae) in two mangrove areas of Cuba. Stomach contents of 88 zooids of Ecteinascidia turbinata Herdman 1880 and the qualitative and quantitative composition of phytoplankton in the water column were studied in Santa Fe (North Coast of Havana) and Punta del Este (SW of Cuba). We identified 59 microalgal species and four tintinnids in the stomachs. Cell size was 75-165 µm in length and 2-105 µm in width. There were not significant differences in microalgal diversity in the water column in the two locations. In both locations, the diatoms had the largest number of species and individuals in stomachs and water. In Santa Fe, dinoflagellate biomass was larger in water and stomach contents, while in Punta del Este the contribution of each group to the stomach content was similar to that of the water column. This species filters in a constant and irregular way during the day, independently of food availability. Rev. Biol. Trop. 55 (2): 499-507. Epub 2007 June, 29
-
Distribución y abundancia de la ascidia Ecteinascidia turbinata (Ascidiacea: Perophoridae) en Cuba
Revista de biologia tropical, 2002Co-Authors: Aida Hernández-zanuy, Santiago Naranjo, José Luis Carballo, Alida García-cagide, Macario EsquivelAbstract:Distribution and abundance of the ascidian Ecteinascidia turbinata (Ascidiacea: Perophoridae) in Cuba. Permanently submerged mangrove roots (Rhizophora mangle) are the main habitat of the ascidian Ecteinascidia turbinata in Cuba. It was occasionally found on black coral (Antiphates caribeana) between 22 and 38 meters deep. This species exhibits a wide distribution in all the mangrove keys surrounding the Island of Cuba but does not occur in riparian or fringing mangroves. Populations of this species are abundant in Cuba: in 75 % of the 58 localities sampled the species was present and in 57 % more than 50 % of the roots held at least one colony. The highest colony densities were found in the northern coast of Pinar del Rio province with values near one colony per lineal meter of mangrove root. We found the highest density (1.46 col/m) and greatest bio- mass at Jutias Key, with values between 25 and 660 g/m. The average of wet biomass in the studied mangroves was 73.63 g/m. Rev. Biol. Trop. 55 (1): 247-254. Epub 2007 March. 31.
-
Aquaculture of Ecteinascidia turbinata Herdman, 1880 as Source of Marine Anticancer Agents
The Biology of Ascidians, 2001Co-Authors: Santiago Naranjo, H. B. Kukurtçu, C. Barbero, S. Martin, José Luis CarballoAbstract:Ecteinascidin-743 (ET-743) is a tetrahydroisoquinoline alkaloid produced by Ecteinascidia turbinata, an Atlanto-Mediterranean species growing in mangroves and coastal meadows. Preclinical and early clinical trials revealed high cytotoxic activity of ET-743 against several resistant human tumours. Phase II studies with ET-743 are being performed at different Cancer centres in Europe and the United States. More than 600 patients suffering from breast, renal sarcomas and melanoma have been treated with ET-743. In correlation with preclinical models, high activity was observed in cases of advanced sarcoma which had relapsed or were resistant to conventional therapy.
Jose Jimeno - One of the best experts on this subject based on the ideXlab platform.
-
Clinical impact of trabectedin (ecteinascidin-743) in advanced/metastatic soft tissue sarcoma
Expert opinion on pharmacotherapy, 2008Co-Authors: Patrick Schöffski, Herlinde Dumez, Pascal Wolter, C Stefan, Agnieszka Wozniak, Jose Jimeno, Allan T. Van OosteromAbstract:Background: Patients with advanced or metastatic non-gastrointestinal stromal tumour soft tissue sarcoma (STS) whose disease progresses during or after chemotherapy with doxorubicin or ifosfamide have few options and very limited life expectancy. In this setting, the DNA and transcription interacting agent trabectedin (ecteinascidin-743), isolated originally from the tunicate Ecteinascidia turbinata, has encouraging activity and is now approved in the European Union. Objective: To review evidence for the efficacy of trabectedin in STSs. Methods: This review includes material known to the authors through preclinical and clinical work with trabectedin, and information from relevant papers and abstracts. Results: Pooled analysis of Phase II studies suggests that around 50% of STS patients, failing conventional chemotherapy, experienced long lasting tumour control (either objective response or stabilization of disease) when treated with trabectedin. Twenty-nine per cent of patients were alive at 2 years, and ...
-
Unique features of the mode of action of ET-743.
The oncologist, 2002Co-Authors: Maurizio D'incalci, Sergio Marchini, Roberto Mantovani, E. Erba, G. Damia, E. Galliera, L. Carrassa, G. Tognon, R. Fruscio, Jose JimenoAbstract:This paper describes the current knowledge of the primary mode of action of a natural product, ecteinascidin 743 (ET-743), derived from the marine tunicate Ecteinascidia turbinata. ET-743 was initially selected for preclinical development because of its potent antitumor activity observed against several human solid tumor types. In vitro, the drug is cytotoxic in the nanomolar range, and in the case of some very sensitive cell lines, in the picomolar range. The large potency differences observed among several solid tumor types indicate that this compound possesses some tumor selectivity, but the molecular basis of these differential effects remains to be elucidated. The present studies were undertaken to evaluate the mechanism of action of ET-743 in this context. The available information on ET-743 binding to DNA and its effects on transcriptional regulation point to a unique behavior of this drug, as it independently affects specific gene transcription in a promoter-dependent way. In addition, ET-743 shows a peculiar pattern of selectivity in cells with different defects in their DNA-repair pathways. These results highlight a unique property of ET-743, possibly explaining why it possesses antitumor activity against tumors that are refractory to standard anticancer drugs, all of which certainly act by mechanisms that are different from that of ET-743. The Oncologist 2002;7:210-216
