[The demonstration of fixed complement with marked anticomplement].

An attempt was made to synthesize a series of non-cytotoxic low molecular weight meta-substituted aromatic ethers (2-4, 5-7) and some of their bioisosteres (14-16) and to evaluate their activity on the activation of human complement (classical pathway) and their intrinsic hemolytic activity. The in vitro assay results of the inhibition of complement-mediated hemolysis by these analogues indicate that the aldehydic meta substituted aromatic ethers show inhibitory potency, while carboxylic acid meta substituted aromatic ethers show hemolytic activity. Some of the bioisosteres exhibit both inhibitory as well as hemolytic property.

Complement Inactivator Proteins↗

PubMed2003

Complement-inhibiting iridoids from Morinda morindoides.

Morinda morindoides (Baker) Milne-Redhead (syn. Gaertnera morindoides Bak.) is one of the most popular medicinal plants in the Democratic Republic of Congo. In relation to its traditional use against rheumatic pains, fractionation of both the EtOAc- and the n-BuOH-soluble fraction of the 80% MeOH extract of the leaves, guided by the anticomplementary activity on the classical activation pathway, yielded eight novel iridoids (1-8), all containing a spirolactone functionality. Their structure was elucidated using spectroscopic methods. Gaertneroside 1, acetylgaertneroside 2, and gaertneric acid 5 were found to inhibit the activation of the classical pathway of the complement system, with IC(50) values between 58 and 69 microM. In addition to the biologically active flavonoids reported before from the same plant, these complement-inhibiting iridoids may contribute at least in part to the traditional use against rheumatic pains.

Complement Inactivator Proteins↗

PubMed2003

Lactones from the leaves of Litsea japonica and their anti-complement activity.

Two new lactones, litsealactone A (1) and litsealactone B (2), were isolated from the leaves of Litsea japonica, together with three known lactones, hamabiwalactone A (3), hamabiwalactone B (4), and akolactone B (5). Hamabiwalactone B (4) and akolactone B (5) significantly inhibited complement activity in an in vitro anti-complement assay, with IC(50) values of 149 and 58 muM, respectively.

Complement Inactivator Proteins↗