Chrobisiamone A, a new bischromone from Cassia siamea and a biomimetic transformation of 5-acetonyl-7-hydroxy-2-methylchromone into cassiarin A

A Bioactivity Versus Ethnobotanical Survey of Medicinal Plants from Nigeria, West Africa

“…Ajaiyeoba et al [100] also reported the use of the leaves and stem bark of Cassia siamea in the treatment of malaria. Investigation of the leaves of this plant led to the isolation of emodin ( 87 ), lupeol ( 88 ) and cassiarin A ( 89 ), with IC 50 values of 5.0 μg mL −1 against the K1 strain for both compounds 87 and 88 and an IC 50 value of 0.02 μM for compound 90 [101, 102]. In Asian traditional folk medicine, the stem bark of Cassia siamea is used as a mild, pleasant, safe purgative; a decoction of the bark is given to treat diabetes; a paste is used as a dressing for ringworm and chilblains; the roots are used as an antipyretic; and the leaves are used for the treatment of constipation, hypertension, and insomnia [101].…”

“…In Asian traditional folk medicine, the stem bark of Cassia siamea is used as a mild, pleasant, safe purgative; a decoction of the bark is given to treat diabetes; a paste is used as a dressing for ringworm and chilblains; the roots are used as an antipyretic; and the leaves are used for the treatment of constipation, hypertension, and insomnia [101]. The vasodilator effect of cassiarin A, could explain the use of this plant in the treatment of hypertension, amongst other ailments [102]. …”

Antimalarial compounds isolated from plants used in traditional medicine

“…The methanol extract of the stem bark of Allanblackia monticola Mildbr. (Clusiaceae) resulted in the isolation of a new prenylated xanthenedione, designated as allanxanthone C (47), together with the known compounds norcowanin (48), mangostin (49) and tovophyllin A (50). Compounds were assayed for their antiplasmodial activity and for their cytotoxicity.…”

“…Three of these compounds (47)(48)(49) were found to be active against Plasmodium: 47, IC50 on FcM29 = 1.3 mM and IC50 on F32 = 6.9 mM; 48, not tested on FcM29 and IC50 on F32 = 6.3 mM; 49, IC50 on FcM29 = 4.1 mM and IC50 on F32 = 7.8 mM, and also showed weak cytotoxicity against human melanoma A375 cells. [30] Tovophyllin A (50) was the most interesting with promising antimalarial activity (IC50 on FcM29 = 0.7 mM and IC50 on F32 = 20.3 mM) and relatively low cytoxicity. [31] A new prenylated xanthone, 5-Omethylcelebixanthone (51), together with a known compound, cochinchinone C (52), were isolated from roots of Cratoxylum cochinchinense Blume (Clusiaceae).…”

Anthraquinones and triterpenoids from Senna siamea (Fabaceae) Lam inhibit poliovirus activity

“…Other confirmed biological activities include; free radicals scavenging, antimicrobial and anti-malarial; Chrobisiamone A isolated from the leaves gave a good in vitro anti-plasmodial activity against parasite Plasmodium falciparum 3D7. Emodin and lupeol isolated from the ethyl acetate fraction were found to be the active principles responsible for the antiplasmodial property of S. siamea, with IC 50 values of 18.5 μM for emodin and 11.7 μM for lupeol (Ajaiyeoba et al, 2003;Kaur et al, 2006;Oshimi et al, 2008). In 2012, Hu and co-workers reported the isolation of antiviral chromones from the stem of Cassia siamea.…”