Calodenin C: A New Guibourtinidol-(4α→8)-afzelechin fromOchna calodendron

Abstract

A new dimeric proanthocyanidin, calodenin C [guibourtinidol-(4alpha-->8)-afzelechin], was isolated from the stem bark of Ochna calodendron and its structure determined on the basis of chemical studies and spectroscopic data, including HMBC and ROESY experiments.

A new procyanidin B from Campylospermum zenkeri (Ochnaceae) and antiplasmodial activity of two derivatives of (±)-serotobenine

“…All these results are confirmed by any correlation in the NOESY spectrum ( Figure S17) between neither H-2 and H-3 nor H-4 and H-3 , respectively. These data corroborated the relative stereochemistry found for other analogues described in the literature (Messanga et al 1998;Mello de et al 1999;Cádiz-Gurrea et al 2014;Klika et al 2015). The additional data emphasized on the double linkage between the two flavonoid units.…”

Nitrile-containing natural products

“…The lophirosides exhibit weak antibacterial activity against Micrococcus luteus but do not act as defensive substances against insects and microorganisms. Three monoesters, lanceolin A (48h), 67 B (48i), 67 and C (48j) 68 are related to the lophirosides and were isolated from sister species Lophira lanceolata and Lophira alata, respectively, that grow in the woody savannas of Cameroon. Simmonsin (48k), from seeds of the jojoba plant (Simmondsia californica) 69 is the only other nitriloside without C2-C3 unsaturation.…”

Chemical Constituents of Cassia abbreviata and Their Anti-HIV-1 Activity

“…In the heteronuclear multiple bond connectivity (HMBC) spectrum, a diagnostic ketal-γ-lactone moiety could easily be deduced according to correlations of H-2″ to C-3″/C-15″, H-3″ to C-10″, H-11″ to C-3″/C-13″, H 2 -12″ to C-13″/C-15″, and H 3 -17″ to C-11″/C-15″, which by further cross peaks of H 2 -4″ to C-5″/C-9″/C-10″ constructed the fragment of planchol A ( 6 ) [ 13 ]. Moreover, HMBC correlations of H-2 to C-1′/C-2′/C-9, H-3 to C-1′/C-2/C-4/C-10, and H-4 to C-5/C-9/C-10 and the large coupling constant of H-2/H-3 ( 3 J H2-H3 = 9.5 Hz) could be used to establish another fragment of guibourtinidol [ 14 ]. These two fragments could be connected via C-4 and C-8″ by the key HMBC correlations of H-4 to C-7″/C-9″ ( Figure 2 ).…”