“…Of the different types of diterpenoids found in the genus, the abietane diterpenoids are the most diverse group. Some of the abietane diterpenoids isolated include 6-formyloxy-7␣-hydroxyroyleanone, coleon U and V in Plectranthus argentatus (Adler et al, 1984), coleon F, C, coleonol C, cariocal and plectrin in Plectranthus barbatus (Rüedi and Eugster, 1973;Grob et al, 1978;Tandon et al, 1978;Kelecom and Dos Santos, 1985;Kreutner et al, 1985;Jin et al, 1990), coleon M, N, O, P, Q and R in Plectranthus caninus (Arihara et al, 1975;Grob et al, 1978), edulone A and 16-O-acetylcoleon D in Plectranthus edulis (Buchbauer et al, 1978;Kunzle et al, 1987), 7␣,11-dihydroxy-12-methoxy-8,11,13-abietatriene in Plectranthus elegans (Dellar et al, 1996), grandidone A and grandidone B in Plectranthus grandidentatus (Uchida et al, 1981), 6,7-dihydroxyroyleanone in Plectranthus hadiensis (syn Plectranthus zeylanicus) (Mehrotra et al, 1989), horminone and 7␣,12-dihydroxy-17(15 → 16)-abeo-abieta-8,12,16-triene-11,14-dione in Plectranthus hereroensis (Batista et al, 1994(Batista et al, , 1996Ferraeira et al, 1997) and lanugon M, N, S, 15-epilanugin F, coleon J and H in Plectranthus lanuginosus (Moir et al, 1973a,b;Schmid et al, 1982;Matloubi-Moghadam et al, 1984). A few of these compounds have been tested for antimicrobial activity and this could explain some of medicinal uses, especially for the treatment of infections, fever and inflammation (Table 1).…”