Lipophilic Metabolites from Five-needle Pines, Pinus armandii and Pinus kwangtungensis, Exhibiting Antibacterial Activity.

Lipophilic extractive metabolites from needles and defoliated twigs of Pinus armandii and P. kwangtungensis were studied by GC-MS. Needles of P. armandii contained predominantly 15- O -functionalized labdane type acids (anticopalic acid), fatty acids, nonacosan-10-ol, sterols, nonacosan-10-ol and sterol saponifiable esters, and acylglycerols. While P. kwangtungensis needles comprised no anticopalic acid, but more trinorlabdane (14,15,16-trinor-8(17)-labdene-13,19-dioic acid) and other labdane type acids, nonacosan-10-ol and its saponifiable esters. The major compounds in the P. armandii defoliated twig extract were abietane and isopimarane type acids, fatty acids, sterols, labdanoids ( cis- abienol), cembranoids (isocembrol and 4- epi -isocembrol), saponifiable sterol esters, and acylglycerols. The same extract of P. kwangtungensis contained larger quantities of fatty acids, caryophyllene oxide, serratanoids, sterols, saponifiable sterol esters, and acylglycerols; but lesser amounts of abietane and isopimarane type acids, cis- abienol, and lacked cembranoids. Both twig and needle extracts of P. armandii and P. kwangtungensis , as well as the extracts' fractions, significantly inhibited the growth of Gram-negative bacteria Serratia marcescens with MIC of 0.1 mg ml -1 . While in most cases they slightly stimulated the growth of Gram-positive bacteria Bacillus subtilis at the same concentrations. Thus, lipophilic extractive compounds from needles and defoliated twigs of both pines are prospective for the development of antiseptics against Gram-negative bacteria.