ABSTRACT
The ocotillol (OCT)-type saponins have been known as a tetracyclic triterpenoid, possessing five- or six-membered epoxy ring in the side chain. Interestingly, this type saponin was mostly found in Panax vietnamensis Ha et Grushv., Araliaceae (VG), hence making VG unique from the other Panax spp. Five OCT-type saponins, majonoside R2, vina-ginsenoside R2, majonoside R1, pseudoginsenoside RT4, vina-ginsenoside R11, together with three protopanaxadiol (PPD)-type saponins and four protopanaxatriol (PPT)-type saponins from VG were evaluated for their antimelanogenic activity. All of isolates were found to be active. More importantly, the five OCT-type saponins inhibited melanin production in B16-F10 mouse melanoma cells, without showing any cytotoxicity. Besides ginsenoside Rd and ginsenoside Rg3 in PPD and notoginsenoside R1 in PPT-type saponins, majonoside R2 was the most potent melanogenesis inhibitory activity in OCT-type saponins. In this article, we highlighted antimelanogenic activity of OCT-type saponins and potential structure-activity relationship (SAR) of ginsenosides. Our results suggested that OCT-type saponins could be used as a depigmentation agent.
Subject(s)
Antineoplastic Agents, Immunological/pharmacology , Ginsenosides/pharmacology , Melanoma/drug therapy , Panax/chemistry , Saponins/pharmacology , Animals , Antineoplastic Agents, Immunological/chemistry , Antineoplastic Agents, Immunological/isolation & purification , Cell Proliferation/drug effects , Cell Survival/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Ginsenosides/chemistry , Ginsenosides/isolation & purification , Melanins/antagonists & inhibitors , Melanins/metabolism , Melanoma/metabolism , Melanoma/pathology , Mice , Molecular Conformation , Plants, Medicinal , Saponins/chemistry , Saponins/isolation & purification , Structure-Activity Relationship , Tumor Cells, CulturedABSTRACT
A new indole alkaloid, leucoridine A N-oxide (1), consisting of two units of a strychnan type of skeleton, was isolated from the leaves of Leuconotis griffithii. Its structure was elucidated by various spectroscopic means such as NMR and MS, and also by chemical means. Antiplasmodial activity against Plasmodium falciparum 3D7 of indole alkaloids isolated from L. griffithii was investigated.
Subject(s)
Antimalarials/chemistry , Antimalarials/pharmacology , Apocynaceae/chemistry , Indole Alkaloids/chemistry , Indole Alkaloids/pharmacology , Plant Extracts/pharmacology , Plasmodium falciparum/drug effects , Magnetic Resonance Spectroscopy , Molecular Structure , Plant Extracts/chemistryABSTRACT
Pseuduvarines A (1) and B (2), two new dioxoaporphine alkaloids with an amino moiety, were isolated from the stem bark of Pseuduvaria rugosa and their structures were elucidated by combination of 2D-NMR spectroscopic analysis. Pseuduvarines A (1) and B (2) showed cytotoxicity against MCF7, HepG2, and HL-60 (1: IC50, 0.9, 21.7, and >50.0 µM, respectively, 2: IC50 >50.0, 15.7, and 12.4 µM, respectively).
