Biomedical subjects

C Patarapanich

Publications and source records attributed to C Patarapanich.

4 recordsLinked to original sources

PubMed1999

New cytotoxic 1-azaanthraquinones and 3-aminonaphthoquinone from the stem bark of Goniothalamus marcanii.

Guided by brine shrimp toxicity and human tumor cell toxicity, fractionation of the alcoholic extract from the stem bark of Goniothalamus marcanii led to the isolation of four new 1-azaanthraquinones: marcanines B (3), C (4), D (5), and E (6), along with two known derivatives: marcanine A and dielsiquinone. A new 5-hydroxy-3-amino-2-aceto-1,4-naphthoquinone (7), a possible 1-azaanthraquinone biosynthetic precursor, was also isolated. The structures of the compounds were elucidated by spectroscopic analyses, mainly 1D and 2D NMR techniques ((1)H, (13)C, NOEDS, COSY, HMQC, and HMBC), as well as comparison with literature data. All the compounds except 6 were evaluated for cytotoxic activity. They exhibited significant cytotoxicity against several human tumor cell lines, A-549, HT-29, MCF7, RPMI, and U251 with the ED(50) in the range of 0.04-3.03 microM.

Anthraquinones↗

PubMed1997

Preliminary evaluation of the anticonvulsant activity of a valproic acid analog: N-(2-propylpentanoyl) urea.

Anticonvulsant activity, lethality and neurotoxicity of a valproic acid (VPA) analog, N-(2-propylpentanoyl) urea (VPU) in comparison to its parent compound were investigated in mice. Intraperitoneally administered VPU demonstrated a higher protection than VPA in both the maximal electroshock seizure (MES) and the pentylenetetrazole (PTZ) tests exhibiting a median effective dose (ED50) of 66 and 57 mg/kg, respectively. VPU weakly blocked the effect of bicuculline and was ineffective in strychnine test. Furthermore, VPU was also active orally demonstrating an ED50 approximately 6 times higher than its ED50 by the intraperitoneal route. Based on the relatively high median lethal dose (LD50), 1553 mg/kg, VPU possesses a greater margin of safety (LD50/ED50) than did VPA. Unwanted (side) effects in terms of impairment of motor activity and neurotoxicity were assessed by the rotorod test, locomotor activity test as well as potentiation of barbiturate sleeping time. The median neurotoxic dose (TD50) as measured by rotorod test were 625 mg/kg for intraperitoneally given VPU. This finding results in higher protective index (PI = TD50/ED50) of VPU (PI = 9.5) than that of VPA (PI = 1.1) implying that, in therapeutic dose, VPU may produce less neurological side effects than did VPA. Superiority of VPU in terms of higher potency in parallel with minimal neurological deficit as assessed by rotorod test was evident throughout the observation period of 12 hours. Similar results on locomotor activity as well as potentiation of barbiturate sleeping time were obtained with VPU and VPA. Thus, VPU is preferably expected to exert minor degree of CNS depression. Taken altogether, our findings demonstrate greater anticovulsant activity for VPU than for VPA. In addition, this compound is also orally active and seems to offer a greater safety margin in parallel with lower unwanted effects in relation to its parent compound. As indicated by the animal data obtained, VPU is an attractive anticonvulsant candidate for further investigation.

Animals↗

PubMed1986

Synthesis and antimicrobial activities of N4-(2-acetoxyethoxymethyl)thiosemicarbazones and N3-(2-acetoxyethoxymethyl)thioureas.

A series of thiosemicarbazones and thioureas having an open-chain analogue of the ribosyl group, the 2-acetoxyethoxymethyl moiety, has been synthesized. Significant growth inhibitory activity versus gram-positive and gram-negative organisms, a yeast, and a mold has been found with the 2-acetoxyethoxymethyl derivatives of N-alkyl-, aryl-, and heteroaryl-thiosemicarbazones and thioureas. The molecules may function as inhibitors of ribonucleotide reductase or in utilization of the carbamyl group in pyrimidine biosynthesis.

Anti-Bacterial Agents↗

PubMedDate not supplied

Additional bioactive heptenes from Melodorum fruticosum.

Four additional new bioactive heptenes, melodorinol [2], homomelodienone [4], 7-hydroxy-6-hydromelodienone [5], and homoisomelodienone [7] have been isolated from Melodorum fruticosum. These compounds were slightly to significantly cytotoxic to human tumor cell lines. Their structures have been determined by comparison of their 1H-nmr, 13C-nmr, and mass spectral data with those of prototype compounds (acetylmelodorinol [1], melodienone 3, and isomelodienone [6]).

Alkenes↗