Acute administration of Mitragyna speciosa (MS) extract (45 and 50 mg/kg) significantly resulted ... more Acute administration of Mitragyna speciosa (MS) extract (45 and 50 mg/kg) significantly resulted in dose-dependent decreases in food and water intakes (P b 0.05) in rats. Prolonged suppressing effects were observed following administration of the MS extract (40 mg/kg) for 60 consecutive days. Moreover, the long-term administration also significantly suppressed weight gaining.
The structure of mitragynaline, an indole alkaloid isolated from Malaysian Mitragyna speciosa, wa... more The structure of mitragynaline, an indole alkaloid isolated from Malaysian Mitragyna speciosa, was revised as formula 3 by analysis of the NMR spectra measured at low temperature and by chemical transformation with DDQ oxidation from the known alkaloid mitragynine (5).
... in Great Britain 0031 9422/91 $300+000 1990 Pergamon Press pic ALKALOIDS FROM MITRAGYNA SPECI... more ... in Great Britain 0031 9422/91 $300+000 1990 Pergamon Press pic ALKALOIDS FROM MITRAGYNA SPECIOSA PETER J. HOUGHTON, AISHAH LATIFF* and ... also demonstrated by a positive Schiff's reaction and by NaBH4 reduction and CO,Me 347 348 PJ HOUGH-TON et ...
AbstractÐA new Corynanthe-type indole alkaloid, (2)-9-methoxymitralactonine (1), having a highly ... more AbstractÐA new Corynanthe-type indole alkaloid, (2)-9-methoxymitralactonine (1), having a highly conjugated system was isolated from the young leaves of Mitragyna speciosa in Malaysia, and its structure was ®rst deduced by spectroscopic analysis and then con®rmed by chiral-total synthesis starting from optically pure epoxy-ketone and 5-methoxy-3,4-dihydro-b-carboline. The chiral HPLC analysis demonstrated that the natural 9-methoxymitralactonine contained predominantly the (2)-enantiomer over the (1)-enantiomer in the ratio of 62:38. q
The leaves of Mitragyna speciosa, a tropical plant known as “kratom,” have been traditionally use... more The leaves of Mitragyna speciosa, a tropical plant known as “kratom,” have been traditionally used as a substitute for opium in Thailand and Malaysia. Mitragynine, a major constituent of M. speciosa, has an opioid agonistic activity, and its derivative 7-hydroxymitragynine (7-OH-mitragynine) (a minor constituent) is much more potent than mitragynine or morphine. Recently, many products containing this plant have been distributed as “incense” on the drug market in Japan for their expected narcotic effects. Despite their potency and their wide distribution for abuse, there are no reports on the quantitative analysis of mitragynine and 7-OH-mitragynine in the raw materials or in the commercial products of kratom. In this study, a method for simultaneous analysis of mitragynine, 7-OH-mitragynine, and other indole alkaloids (speciogynine, speciociliatine, and paynantheine), present in the raw materials and commercial products of kratom, was developed using liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS). By this method, mitragynine, 7-OH-mitragynine, and the other alkaloids were detected in 11 of the 13 products. The content of mitragynine in the products ranged from 1% to 6%, and that of 7-OH-mitragynine from 0.01% to 0.04%. Because 7-OH-mitragynine is much more potent than morphine, M. speciosa abuse is a matter of major concern. The present analytical method is considered useful for the screening of M. speciosa products in the drug market.
Mitragynine is an indole alkaloid isolated from the Thai medicinal plant Mitragyna speciosa. We p... more Mitragynine is an indole alkaloid isolated from the Thai medicinal plant Mitragyna speciosa. We previously reported the morphine-like action of mitragynine and its related compounds in the in vitro assays. In the present study, we investigated the opioid effects of 7-hydroxymitragynine, which is isolated as its novel constituent, on contraction of isolated ileum, binding of the specific ligands to opioid receptors and nociceptive stimuli in mice. In guinea-pig ileum, 7-hydroxymitragynine inhibited electrically induced contraction through the opioid receptors. Receptorbinding assays revealed that 7-hydroxymitragynine has a higher affinity for A-opioid receptors relative to the other opioid receptors. Administration of 7-hydroxymitragynine (2.5 -10 mg/kg, s.c.) induced dose-dependent antinociceptive effects in tail-flick and hot-plate tests in mice. Its effect was more potent than that of morphine in both tests. When orally administered, 7-hydroxymitragynine (5-10 mg/kg) showed potent antinociceptive activities in tail-flick and hot-plate tests. In contrast, only weak antinociception was observed in the case of oral administration of morphine at a dose of 20 mg/kg. It was found that 7-hydroxymitragynine is a novel opioid agonist that is structurally different from the other opioid agonists, and has potent analgesic activity when orally administered. D
A new indole alkaloid, 7-hydroxyspeciociliatine (1), was isolated from the fruits of Malaysian Mi... more A new indole alkaloid, 7-hydroxyspeciociliatine (1), was isolated from the fruits of Malaysian Mitragyna speciosa Korth., together with 11 known indole and oxindole alkaloids (3–13). The structure of the new compound was determined by spectroscopic analysis and chemical conversion. The opioid agonistic activity of the new alkaloid was investigated in guinea-pig ileum experiments. The compound was found to have a weak stimulatory effect on μ-opioid receptors.
Acute administration of Mitragyna speciosa (MS) extract (45 and 50 mg/kg) significantly resulted ... more Acute administration of Mitragyna speciosa (MS) extract (45 and 50 mg/kg) significantly resulted in dose-dependent decreases in food and water intakes (P b 0.05) in rats. Prolonged suppressing effects were observed following administration of the MS extract (40 mg/kg) for 60 consecutive days. Moreover, the long-term administration also significantly suppressed weight gaining.
The structure of mitragynaline, an indole alkaloid isolated from Malaysian Mitragyna speciosa, wa... more The structure of mitragynaline, an indole alkaloid isolated from Malaysian Mitragyna speciosa, was revised as formula 3 by analysis of the NMR spectra measured at low temperature and by chemical transformation with DDQ oxidation from the known alkaloid mitragynine (5).
... in Great Britain 0031 9422/91 $300+000 1990 Pergamon Press pic ALKALOIDS FROM MITRAGYNA SPECI... more ... in Great Britain 0031 9422/91 $300+000 1990 Pergamon Press pic ALKALOIDS FROM MITRAGYNA SPECIOSA PETER J. HOUGHTON, AISHAH LATIFF* and ... also demonstrated by a positive Schiff's reaction and by NaBH4 reduction and CO,Me 347 348 PJ HOUGH-TON et ...
AbstractÐA new Corynanthe-type indole alkaloid, (2)-9-methoxymitralactonine (1), having a highly ... more AbstractÐA new Corynanthe-type indole alkaloid, (2)-9-methoxymitralactonine (1), having a highly conjugated system was isolated from the young leaves of Mitragyna speciosa in Malaysia, and its structure was ®rst deduced by spectroscopic analysis and then con®rmed by chiral-total synthesis starting from optically pure epoxy-ketone and 5-methoxy-3,4-dihydro-b-carboline. The chiral HPLC analysis demonstrated that the natural 9-methoxymitralactonine contained predominantly the (2)-enantiomer over the (1)-enantiomer in the ratio of 62:38. q
The leaves of Mitragyna speciosa, a tropical plant known as “kratom,” have been traditionally use... more The leaves of Mitragyna speciosa, a tropical plant known as “kratom,” have been traditionally used as a substitute for opium in Thailand and Malaysia. Mitragynine, a major constituent of M. speciosa, has an opioid agonistic activity, and its derivative 7-hydroxymitragynine (7-OH-mitragynine) (a minor constituent) is much more potent than mitragynine or morphine. Recently, many products containing this plant have been distributed as “incense” on the drug market in Japan for their expected narcotic effects. Despite their potency and their wide distribution for abuse, there are no reports on the quantitative analysis of mitragynine and 7-OH-mitragynine in the raw materials or in the commercial products of kratom. In this study, a method for simultaneous analysis of mitragynine, 7-OH-mitragynine, and other indole alkaloids (speciogynine, speciociliatine, and paynantheine), present in the raw materials and commercial products of kratom, was developed using liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS). By this method, mitragynine, 7-OH-mitragynine, and the other alkaloids were detected in 11 of the 13 products. The content of mitragynine in the products ranged from 1% to 6%, and that of 7-OH-mitragynine from 0.01% to 0.04%. Because 7-OH-mitragynine is much more potent than morphine, M. speciosa abuse is a matter of major concern. The present analytical method is considered useful for the screening of M. speciosa products in the drug market.
Mitragynine is an indole alkaloid isolated from the Thai medicinal plant Mitragyna speciosa. We p... more Mitragynine is an indole alkaloid isolated from the Thai medicinal plant Mitragyna speciosa. We previously reported the morphine-like action of mitragynine and its related compounds in the in vitro assays. In the present study, we investigated the opioid effects of 7-hydroxymitragynine, which is isolated as its novel constituent, on contraction of isolated ileum, binding of the specific ligands to opioid receptors and nociceptive stimuli in mice. In guinea-pig ileum, 7-hydroxymitragynine inhibited electrically induced contraction through the opioid receptors. Receptorbinding assays revealed that 7-hydroxymitragynine has a higher affinity for A-opioid receptors relative to the other opioid receptors. Administration of 7-hydroxymitragynine (2.5 -10 mg/kg, s.c.) induced dose-dependent antinociceptive effects in tail-flick and hot-plate tests in mice. Its effect was more potent than that of morphine in both tests. When orally administered, 7-hydroxymitragynine (5-10 mg/kg) showed potent antinociceptive activities in tail-flick and hot-plate tests. In contrast, only weak antinociception was observed in the case of oral administration of morphine at a dose of 20 mg/kg. It was found that 7-hydroxymitragynine is a novel opioid agonist that is structurally different from the other opioid agonists, and has potent analgesic activity when orally administered. D
A new indole alkaloid, 7-hydroxyspeciociliatine (1), was isolated from the fruits of Malaysian Mi... more A new indole alkaloid, 7-hydroxyspeciociliatine (1), was isolated from the fruits of Malaysian Mitragyna speciosa Korth., together with 11 known indole and oxindole alkaloids (3–13). The structure of the new compound was determined by spectroscopic analysis and chemical conversion. The opioid agonistic activity of the new alkaloid was investigated in guinea-pig ileum experiments. The compound was found to have a weak stimulatory effect on μ-opioid receptors.
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