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Salvia species are important medicinal and culinary plants, and they have been the subject of numerous chemical and biological studies. The bioactive triterpenoids of Salvia species, reported in the literature to date, are reviewed. About 200 triterpenoids, almost 80 of which are new, isolated, and characterized from about 100 Salvia species, are presented herein. In addition to the diverse biological activities of the pure triterpenoids, studies on biological activity of extracts of Salvia species are also described.

The three new triterpenes (1-3) and five known triterpenes and a sterol were isolated from the acetone extract of a Turkish collection of Salvia kronenburgii. The structures of the new triterpenes were established as 1beta,2alpha-dihydroxy-3beta-acetoxy-11-oxours-12-ene (1), 2alpha,20beta-dihydroxy-3beta-acetoxyurs-9(11),12-diene (2), and 1beta,2alpha-dihydroxy-3beta-acetoxyurs-9(11),12-diene (3) on the basis of spectral analyses, including 1D and 2D NMR and mass spectroscopy. It is probable that compounds 2 and 3 are artifacts from dehydration of the corresponding allylic alcohols. 1beta,2alpha,3beta,11alpha-Tetrahydroxyurs-12-ene (5), the most abundant compound in the extract, was found to be highly cytotoxic to renal, non-small cell lung, and breast cancer cell lines.

Four new sesquiterpenes, (8R)-8-bromo-10-epi-beta-snyderol (1), (8S)-8-bromo-beta-snyderol (2), 5-bromo-3-(3'-hydroxy-3'-methylpent-4'-enylidene)-2,4,4-trimethylcyclohexanone (3), and the epoxide 4, have been isolated from the chloroform-methanol extract of Laurencia obtusa, together with the three known compounds alpha-snyderol (5), alpha-snyderol acetate (6), and stigmasterol. The structures of the isolated compounds were elucidated through spectroscopic analyses. Compound 1 showed antimalarial activity, with IC(50) values of 2700 and 4000 ng/mL against the D6 and W2 clones of Plasmodium falciparum, respectively.

A new norditerpenoid and six new triterpenoids were isolated from the roots of Salvia kronenburgii. The new diterpenoid was kronenquinone (1). The new triterpenoids were 1β,2α,3β,11α-tetrahydroxy-olean-12-ene (2), 1β,2α,3β,11α-tetrahydroxy-urs-12-ene (3), 2α-acetoxy-urs-5,12-diene-3β,11α-diol (4), 3α-acetoxy-urs-12-ene-1β,11α-diol (5), 1β,3α,11α-trihydroxy-urs-12-ene (6), 2α,3β,11α-trihydroxy-urs-12-ene (7), and the known triterpenes 3β-acetoxy-urs-12-ene-1β,2α,11α-triol (8) and 3β-acetoxyolean-12-ene-1β,2α,11α-triol (9). Structures were determined by NMR and MS techniques.

From the roots of Salvia multicaulis, four new aromatic norditerpenoids, multicaulin (1), 12-demethylmulticauline (2), multiorthoquinone (3), and 12-demethylmultiorthoquinone (4), two new abietane diterpenoids, 12-methyl-5-dehydrohorminone (5) and 12-methyl-5-dehydroacetylhorminone (6), as well as a new pimarane diterpenoid, salvipimarone (7), were isolated. Also obtained in this investigation were the known compounds alpha-amyrin, hinokione, horminone, lupeol, manool, 1-oxoferruginol, 18-oxoferruginol, pisiferal, and sempervirol. The structures of compounds 1-7 were established by 1D and 2D NMR techniques and by chemical methods. The antituberculous activity of 1-7 was tested against Mycobacterium tuberculosis strain H37Rv, and all compounds were found to be significantly active, with 2 and 4-6 being the most potent substances. Six of these novel compounds were evaluated against a number of additional bacterial cultures.

A beta-carboline-, a tryptamine-, and two phenylethylamine-derived alkaloids and three known aromatic compounds were isolated from the aerial parts and roots of Cyathobasis fruticulosa (Bunge) Aellen, and their structures were elucidated by spectroscopic techniques. The one new alkaloid, N-methyl-N-formyl-4-hydroxy-beta-phenylethylamine (1), showed marginal antifungal activity.

The aerial parts of Salvia yosgadensis afforded five new terpenes with unusual skeletons, together with two known norditerpenes, ambreinolide and norambreinolide. The new compounds were elucidated as 6α-hydroxyambreinolide, 6α-hydroxynorambreinolide, 6α-hydroxy-8α-acetoxy-13,14,15,16-tetranorlabdan-12-oic acid, and two 19,20-dinorsesterterpenes, named as yosgadensonol and 13-epi-yosgadensonol. Their structures were determined by spectroscopic means, particularly by extensive 1D and 2D NMR studies.

Three new direrpenoids, 6-oxoroyleanone-18-oic acid {1}, 6-oxo-12-methylroyleanone-18-oic acid {2} and horminone-18-oic acid {3}, and a new linear sesquiterpene, salvinine {4}, together with a group of known aromatic acids, were isolated from the aerial parts of Salvia divaricata

The acetone extract of Nepeta caesarea yielded four new nepetalic acid derivatives, 3'alpha-[beta-sitosteryl-3beta-oxy]dihydronepetalactone (1), 3'beta-[5alpha-stigmast-7-ene-3beta-oxy]dihydronepetalact one (2), 3'alpha-[olean-12-ene-28-oyl-3beta-oxy]dihydronepetalactone (3), and 3'alpha-[lup-20(29)-ene-28-ol-3beta-oxy]dihydronepetalactone (4). The structures were elucidated by NMR and MS techniques.

The petroleum ether and acetone extracts of the aerial parts of Sideritis arguta afforded two new and six known diterpenoids with the ent-kaurane skeleton. The structures of the new diterpenoids were determined as ent-7alpha,18-diacetoxy-16beta-hydroxykaurane (diacetyldistanol) (1) and ent-7alpha-acetoxy,15alpha,18-dihydroxykaur-16-ene (15-epi-eubol) (2) by spectroscopic data interpretation. Antioxidant potential was investigated for the ent-kauranes and the plant extracts by three methods (beta-carotene bleaching, free-radical scavenging, and superoxide-anion scavenging activity). Acetylcholinesterase and butyrylcholinesterase inhibitory activity were also evaluated, and the ent-kauranes eubol (3), sideroxol (5), and 7-epi-candicandiol (6) exhibited moderate butyrylcholinesterase inhibitory activity.

A simplified hplc system is described for the detection of compounds capable of binding to DNA. Compounds known to interact with DNA were found to invoke a positive response with this system, and the concentration-dependence and sensitivity were determined. When applied to 17 randomly selected plant extracts, five elicited a positive response and, of these, four were subsequently found to be cytotoxic with cultured KB or P-388 cells. As described in a companion paper, one of these extracts (derived from Albizia amara) has been further processed and found to contain a group of structurally-unique macrocyclic alkaloids that demonstrate a variety of biological activities. Therefore, this approach should prove a value in facilitating the identification of plant extracts that contain substances capable of binding to DNA and the subsequent activity-directed fractionation for the procurement of active principles. As a prescreen or monitor, these relatively uncomplicated hplc procedures can be used in laboratories not prepared to perform more complicated or costly bioassay techniques. Thus, the pool of potentially active novel chemical substances to be considered for more advanced testing could be increased.

Two new rearranged neo-clerodane diterpenoids, alysines D (1) and E (2), were isolated from the aerial parts of Teucrium alyssifolium. Their structures were established by spectral methods including 1D and 2D NMR techniques.

The roots of Salvia blepharochlaena have yielded two new diterpenoids, blephaein (1) and O-methylpisiferic acid methyl ester (2), together with eight known diterpenoids. The structures of the new compounds were established by spectroscopic analysis and by some chemical reactions. Potent antibacterial activity was exhibited by the known compounds horminone (9) and 7-acetylhorminone (10) against Staphylococcus aureus ATCC 6538 P, Staphylococcus epidermidis ATCC 12226, and Bacillus subtilis ATCC 6633. Horminone was also found to be active against Enterococcus faecalis ATCC 29212.