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Papers by Ratsami Lekphrom

Ethnopharmacological relevance: Goniothalamus laoticus (Annonaceae) is being used traditionally a... more Ethnopharmacological relevance: Goniothalamus laoticus (Annonaceae) is being used traditionally as a tonic and a febrifuge by the local people in the northeastern part of Thailand. Aim of study: To investigate the Thai medicinal plant, Goniothalamus laoticus, for antiplasmodial, antimycobacterial and cytotoxicity activities. Materials and methods: The flowers extracts of Goniothalamus laoticus were isolated by chromatographic techniques. Structures of isolated compounds were identified by spectroscopic methods. The antiplasmodial, antimycobacterial and cytotoxicity evaluation of styryllactone derivatives and alkaloid were also performed.

Tetrahedron, 2012

ABSTRACT Four new aristolane sesquiterpenes named nambinones A–C (1–3) and 1-epi-nambinone B (4),... more ABSTRACT Four new aristolane sesquiterpenes named nambinones A–C (1–3) and 1-epi-nambinone B (4), a new sesquiterpene, nambinone D (5), a known compound, aurisin A (6) as well as a new dimeric sesquiterpene, aurisin K (7), were isolated from two isolates of luminescent mushroom, Neonothopanus nambi, PW1 and PW2. These structures were established on the basis of spectroscopic evidence. The relative configuration of 6 was determined by X-ray crystallographic analysis. Compounds 6 and 7 exhibited antimalarial activity against Plasmodium falciparum and antimycobacterial activity against Mycobacterium tuberculosis. Compounds 3, 6, and 7 showed cytotoxicity against NCI-H187 cancer cell lines. In addition, 6 and 7 showed cytotoxicity against the cholangiocarcinoma cell lines.

Planta Medica, 2010

Two new diterpenes, 4-epi-triptobenzene L (1) and 12-O-deacetyl-6-O-acetyl-19-acetyloxycoleon Q (... more Two new diterpenes, 4-epi-triptobenzene L (1) and 12-O-deacetyl-6-O-acetyl-19-acetyloxycoleon Q (2), as well as eight known diterpenes (3-10) were isolated from the aerial parts of Anisochilus hamandii. Structures of the isolated compounds were identified from spectroscopic evidence. Compounds 1, 2, 5, and 10 exhibited antiplasmodial activity against Plasmodium falciparum (IC 50 4.70, 2.90, 3.03, and 7.20 µg/mL, respectively), while 3, 5, and 7 showed antimycobacterial activity against Mycobacterium tuberculosis (MIC 50 µg/mL). In addition, only 10 showed strong cytotoxicity against NCI-H187 cells (IC 50 4.43 µg/mL).

Natural Product Research, 2014

The first phytochemical investigation of the bark of Akschindlium godefroyanum (Kuntze) H. Ohashi... more The first phytochemical investigation of the bark of Akschindlium godefroyanum (Kuntze) H. Ohashi (Fabaceae), a Thai herbal medicine, resulted in the isolation of two new flavanonols, 7,3',5'-trihydroxy-5-methoxyflavanonol (1) and 7,4'-dihydroxy-5,3'-dimethoxyflavanonol (2), and eight known compounds comprising one flavonol, geraldol (3); three flavanonols, (+)-taxifolin (4), (+)-fustin (5) and aromadendrin 5-methyl ether (6); one catechin, (-)-epigallocatechin (7); one triterpenoid, lupeol (8); one steroid, stigmasterol (9) and one steroid glycoside, stigmasterol-3-O-β-d-glucoside (10). Their structures were identified by spectroscopic methods.

Journal of Natural Products, 2007

Archives of Pharmacal Research, 2011

A new 7-oxygenated coumarin, 7-demethylmurralonginol isovalerate (1), and a new natural product, ... more A new 7-oxygenated coumarin, 7-demethylmurralonginol isovalerate (1), and a new natural product, murralonginol (2), together with seven known 7-oxygenated coumarins, murralonginol isovalerate (3), murralongin (4), micromelin (5), scopoletin (6), microminutin (7), murrangatin (8), and minumicrolin (9), were isolated from the fruits of Micromelum minutum. The structures of these compounds were established on the basis of their 1D and 2D NMR spectroscopic data. Among these isolates, compounds 2 and 4 - 9 exhibited cytotoxicity against cholangiocarcinoma cell line, KKU-100.

Ethnopharmacological relevance: Goniothalamus laoticus (Annonaceae) is being used traditionally a... more Ethnopharmacological relevance: Goniothalamus laoticus (Annonaceae) is being used traditionally as a tonic and a febrifuge by the local people in the northeastern part of Thailand. Aim of study: To investigate the Thai medicinal plant, Goniothalamus laoticus, for antiplasmodial, antimycobacterial and cytotoxicity activities. Materials and methods: The flowers extracts of Goniothalamus laoticus were isolated by chromatographic techniques. Structures of isolated compounds were identified by spectroscopic methods. The antiplasmodial, antimycobacterial and cytotoxicity evaluation of styryllactone derivatives and alkaloid were also performed.

Tetrahedron, 2012

ABSTRACT Four new aristolane sesquiterpenes named nambinones A–C (1–3) and 1-epi-nambinone B (4),... more ABSTRACT Four new aristolane sesquiterpenes named nambinones A–C (1–3) and 1-epi-nambinone B (4), a new sesquiterpene, nambinone D (5), a known compound, aurisin A (6) as well as a new dimeric sesquiterpene, aurisin K (7), were isolated from two isolates of luminescent mushroom, Neonothopanus nambi, PW1 and PW2. These structures were established on the basis of spectroscopic evidence. The relative configuration of 6 was determined by X-ray crystallographic analysis. Compounds 6 and 7 exhibited antimalarial activity against Plasmodium falciparum and antimycobacterial activity against Mycobacterium tuberculosis. Compounds 3, 6, and 7 showed cytotoxicity against NCI-H187 cancer cell lines. In addition, 6 and 7 showed cytotoxicity against the cholangiocarcinoma cell lines.

Planta Medica, 2010

Two new diterpenes, 4-epi-triptobenzene L (1) and 12-O-deacetyl-6-O-acetyl-19-acetyloxycoleon Q (... more Two new diterpenes, 4-epi-triptobenzene L (1) and 12-O-deacetyl-6-O-acetyl-19-acetyloxycoleon Q (2), as well as eight known diterpenes (3-10) were isolated from the aerial parts of Anisochilus hamandii. Structures of the isolated compounds were identified from spectroscopic evidence. Compounds 1, 2, 5, and 10 exhibited antiplasmodial activity against Plasmodium falciparum (IC 50 4.70, 2.90, 3.03, and 7.20 µg/mL, respectively), while 3, 5, and 7 showed antimycobacterial activity against Mycobacterium tuberculosis (MIC 50 µg/mL). In addition, only 10 showed strong cytotoxicity against NCI-H187 cells (IC 50 4.43 µg/mL).

Natural Product Research, 2014

The first phytochemical investigation of the bark of Akschindlium godefroyanum (Kuntze) H. Ohashi... more The first phytochemical investigation of the bark of Akschindlium godefroyanum (Kuntze) H. Ohashi (Fabaceae), a Thai herbal medicine, resulted in the isolation of two new flavanonols, 7,3',5'-trihydroxy-5-methoxyflavanonol (1) and 7,4'-dihydroxy-5,3'-dimethoxyflavanonol (2), and eight known compounds comprising one flavonol, geraldol (3); three flavanonols, (+)-taxifolin (4), (+)-fustin (5) and aromadendrin 5-methyl ether (6); one catechin, (-)-epigallocatechin (7); one triterpenoid, lupeol (8); one steroid, stigmasterol (9) and one steroid glycoside, stigmasterol-3-O-β-d-glucoside (10). Their structures were identified by spectroscopic methods.

Journal of Natural Products, 2007

Archives of Pharmacal Research, 2011

A new 7-oxygenated coumarin, 7-demethylmurralonginol isovalerate (1), and a new natural product, ... more A new 7-oxygenated coumarin, 7-demethylmurralonginol isovalerate (1), and a new natural product, murralonginol (2), together with seven known 7-oxygenated coumarins, murralonginol isovalerate (3), murralongin (4), micromelin (5), scopoletin (6), microminutin (7), murrangatin (8), and minumicrolin (9), were isolated from the fruits of Micromelum minutum. The structures of these compounds were established on the basis of their 1D and 2D NMR spectroscopic data. Among these isolates, compounds 2 and 4 - 9 exhibited cytotoxicity against cholangiocarcinoma cell line, KKU-100.