Plumeran alkaloids from Kopsia profunda

Sim

2002

HCA

Self Cite

Section: Experimental Partmentioning

confidence: 99%

Vobasonidine and Vobatricine, Novel Bisindole Alkaloids from a Malayan Tabernaemontana

Sim

2002

HCA

Self Cite

“…EtOH extracts with dil. acid as have described in [20]. The alkaloids were isolated by initial CC (SiO 2 ; CH 2 Cl 2 with increasing proportions of MeOH), followed by rechromatography of the appropriate partially resolved fractions using CC or prep.…”

mentioning

confidence: 99%

Conomicidines A and B, Unusual Alkaloid–Hydroxycinnamyl Alcohol Conjugates from Tabernaemontana corymbosa

Lim

2009

Helvetica Chimica Acta

Self Cite

Conomicidines A and B (1a and 2a, resp.) together with the diastereomeric isoconomicidines A and B (1b and 2b, resp.) were isolated from Tabernaemontana corymbosa as unresolvable mixtures of the (1'S,2'S)-and (1'R,2'R)-diastereoisomers (i.e., 1a and 1b; 2a and 2b). These novel natural products are constituted from the union of an iboga alkaloid, ibogaine, and hydroxycinnamyl alcohol moieties, and represent the first examples of such alkaloid -hydroxycinnamyl alcohol conjugates. The structures were determined by spectroscopic methods, including the extensive use of NOE experiments for the assignment of the configuration.

“…Extraction of the ground stem-bark material was carried out in the usual manner by partitioning the concentrated EtOH extract with dil. acid as described in [37]. The alkaloids were isolated by initial column chromatography on silica gel by using CHCl 3 with increasing proportions of MeOH, followed by rechromatography of appropriate partially resolved fractions by centrifugal TLC.…”

mentioning

confidence: 99%

Biologically Active Ibogan and Vallesamine Derivatives from Tabernaemontana divaricata

Chemistry & Biodiversity

Pang

Choo

et al. 2004

Self Cite

Six new indole alkaloids, viz., (3S)-3-cyanocoronaridine (2), (3S)-3-cyanoisovoacangine (3), conolobine A (5), conolobine B (6), conolidine (7), and (3R/3S)-3-ethoxyvoacangine (8), in addition to 36 known ones, were obtained from the stem-bark extract of the Malayan Tabernaemontana divaricata. The structures were determined by NMR and MS analysis. The CN-substituted alkaloids showed appreciable cytotoxicity towards the KB human oral epidermoid carcinoma cell-line.