Chemical investigation of the fruits of Garcinia schomburgkiana collected in Vietnam led to the isolation of eight new schomburgkianones, A–H (1–8), four known (9–12) polyprenylated benzoylphloroglucinols, and four known biflavonoids. The structures of these compounds were elucidated by spectroscopic and chemical means. The absolute configuration at C-40 of 1 and 2 was determined by 1H NMR analyses of their MPA esters. The configuration of the bicyclo[3.3.1]nonane core of the polyprenylated benzoylphloroglucinols was assigned by comparison of their experimental ECD spectra with those of related compounds. The polyprenylated benzoylphloroglucinols exhibited inhibitory activities against mammalian DNA polymerases α and λ, with IC50 values ranging from 5.0 to 8.8 μM. Compounds 1, 2, 4, 5, and 9–11 showed cytotoxic effects against HeLa human cervical cancer cells with median lethal dose values lower than 10 μM.

A spore-derived mycobiont of a crustose Pyrenula sp. lichen collected in Vietnam was cultivated on a malt-yeast extract medium supplemented with 10% sucrose. Chemical investigation of the cultivated colonies led to the isolation of eight new alkylated decalin-type polyketides (1–8) along with three known compounds. The structures of these compounds were elucidated by spectroscopic and chemical means. This is the first instance of this type of polyketide being isolated from a cultured lichen mycobiont. The isolated polyketides 1 and 7 exhibited inhibitory activities against mammalian DNA polymerases α and β with IC50 values ranging from 8.1 to 19.5 μM. Compound 1 showed cytotoxic effects against the HCT116 human colon carcinoma cultured cell line with an IC50 value of 6.4 ± 0.7 μM.

Spore-derived mycobionts of the crustose lichen Sarcographa tricosa were cultivated on a malt-yeast extract medium supplemented with 10% sucrose. Chemical investigation of the cultivated colonies led to isolation of three eremophilane-type sesquiterpenes, 3-epi-petasol (1), dihydropetasol (2) and sarcographol (3), together with six known eremophilanes and ergosterol peroxide. These structures were elucidated by spectroscopic and chemical methods. This is the first report of eremophilane-type sesquiterpenes from the cultured mycobionts of lichen.Graphical abstractSpore-derived mycobionts of the crustose lichen Sarcographa tricosa were cultivated on a malt-yeast extract medium supplemented with 10% sucrose. Chemical investigation of the cultivated colonies led to isolation of three eremophilane-type sesquiterpenes, 3-epi-petasol (1), dihydropetasol (2) and sarcographol (3) as well as six known eremophilanes and ergosterol peroxide. Their structures were determined by spectroscopic and chemical methods.Highlights► Spore-derived mycobionts of the Vietnamese lichen Sarcographa tricosa were cultivated. ► Eremophilane-type sesquiterpenes were isolated from the cultures and their structures were determined. ► This is the first instance of isolation of eremophilane-type sesquiterpenes from lichen mycobionts in culture.

Five phenolic glycosides 1–5 and an iridoid glucoside 6 were isolated, together with 22 known compounds, from the dried barks and woods of Strychnosaxillaris. Their structures were determined by application of spectroscopic (NMR, MS) and chemical methodologies.Five phenolic glycosides 1–5 and an iridoid glucoside 6 were isolated, together with 22 known compounds, from the dried barks and woods of Strychnos axillaris. The structures of the compounds were determined by spectroscopic and chemical means.

Spore-derived mycobionts of the lichen Lecanora iseana were cultivated on a malt-yeast extract medium supplemented with 10% sucrose and their metabolites were investigated. Four 3,7-dihydroxy-1,9-dimethyldibenzofuran derivatives along with the known 3,7-dihydroxy-1,9-dimethyldibenzofuran and five norlichexanthone derivatives were isolated. Their structures were determined by spectroscopic methods.The spore-derived mycobionts of the lichen Lecanora iseana were cultivated on a malt-yeast extract medium supplemented with 10% sucrose. The investigation of the metabolites resulted in isolation of four new dibenzofurans 1–4, as well as six known compounds, 3,7-dihydro-1,9-dimethyldibenzofuran (5) five norlichexanthone derivatives.

The spore-derived mycobionts of the lichen Pyrenula sp. were cultivated on a malt–yeast extract medium supplemented with 10% sucrose. The investigation of their metabolites resulted in isolation of four compounds, three isocoumarins and a biogenetically related benzofuran; their structures were determined by spectroscopic methods.The spore-derived mycobionts of the lichen Pyrenula sp. were cultivated on a malt–yeast extract medium supplemented with 10% sucrose. The investigation of the metabolites resulted in isolation of four compounds, three isocoumarins 1–3 and a benzofuran 4.

The spore-derived mycobionts of the lichen Graphis prunicola, G. cognata and G. scripta were cultivated on a malt–yeast extract medium supplemented with 10% sucrose and their metabolites were investigated. Graphislactones A–D were isolated from the cultures of G. prunicola, while alternariol and graphislactones A and C were isolated from those of G. cognata. From the cultured mycobionts of G. scripta, a new 6H-dibenzo[b,d]pyran-6-one derivative, graphislactone E with graphislactones A and C was obtained. On the other hand, cultivation of the mycobionts of G. prunicola on a malt–yeast extract medium supplemented with 2.5% sucrose and 0.25% sodium acetate produced two new metabolites, graphislactones E and F. Their structures were determined by spectroscopic methods. The biogenetic origin of the carbon skeleton in both compounds was verified by administering sodium [1-13C]-acetate and sodium [1,2-13C2]-acetate.

From the dried roots of Neonauclea sessilifolia, two new chromone-secoiridoid glycosides, sessilifoside and 7″-O-β-d-glucopyranosylsessilifoside, and three novel indole alkaloid glycosides, neonaucleosides A, B, and C, were isolated along with the main known glycosides, 5-hydroxy-2-methylchromone-7-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside, sweroside, loganin, grandifloroside, and quinovic acid 3β-O-β-d-quinovopyranoside-28-O-β-d-glucopyranoside. The structures of these new glycosides were determined by spectroscopic and chemical means. Neonaucleoside A and its C-3 epimer were prepared from secologanin and tryptamine.From the dried roots of Neonauclea sessilifolia, two chromone-secoiridoid glycosides 1, 2 and three indole alkaloid glycosides 3–5 were isolated. The structures of these new glycosides were determined by spectroscopic and chemical means.

Phytochemical investigation of the dried leaves of Syringa afghanica, has led to the isolation of nine secoiridoid glucosides, safghanosides A–H and 2″-epi-frameroside, as well as an iridoid glucoside, syringafghanoside along with nineteen known compounds. The structures were elucidated by spectroscopic and chemical means.Nine secoiridoid glucosides, safghanosides A–H and 2″-epi-frameroside, as well as an iridoid glucoside, syringafghanoside, have been isolated from the leaves of Syringa afghanica. Their structures were elucidated by spectroscopic and chemical means.

From the dried roots of Cephaelis acuminata, five tetrahydroisoquinoline-monoterpene glycosides, 2-O-β-d-glucopyranosyldemethylalangiside, demethylisoalangiside, 6″-O-β-d-glucopyranosylipecoside, 6″-O-α-d-glucopyranosylipecoside and (4R)-4-hydroxyipecoside, were isolated. The structures of these glycosides were determined by spectroscopic and chemical means.From the dried roots of Cephaelis acuminata, five tetrahydroisoquinoline-monoterpene glycosides 1–5 were isolated. The structures of these glycosides were determined by spectroscopic and chemical means.

From the cultures of the spore-derived mycobionts of the lichen Lecanora cinereocarnea, five dibenzofurans, 3,7-dihydroxy-1,9-dimethyldibenzofuran, 2-chloro-3,7-dihydroxy-1,9-dimethyldibenzofuran, 2,8-dichloro-3,7-dihydroxy-1,9-dimethyldibenzofuran, 3-hydroxy-7-methoxy-1,9-dimethyldibenzofuran, and 2-chloro-7-hydroxy-3-methoxy-1,9-dimethyldibenzofuran, were isolated. Their structures were determined by spectroscopic methods.Five dibenzofurans have been isolated from the cultures of the spore-derived mycobionts of the lichen Lecanora cinereocarnea

From the water soluble fraction of the dried fruits of Alangium lamarckii, four tetrahydroisoquinoline-monoterpene glycosides, 6-O-methyl-N-deacetylisoipecosidic acid, 7-O-methyl-N-deacetylisoipecosidic acid, 6,7-di-O-methyl-N-deacetylisoipecosidic acid and 6″-O-α-d-glucopyranosyl-6-O-methyl-N-deacetylisoipecosidic acid, and an iridoid glycoside, 6′-O-α-d-glucopyranosylloganic acid, were isolated, together with six known compounds. The structures of the previously unknown compounds were determined by spectroscopic and chemical means. The significance of these glucosides in the biogenesis of Alangium alkaloids is discussed; 6-O-methyl-N-deacetylisoipecosidic acid was also chemically converted into 10-O-demethylprotoemetine and dihydroisoalangine.

Investigation of the leaves of Fraxinus americana led to the isolation of five secoiridoid glucosides, demethylligstroside, (2″R)- and (2″S)-2″-hydroxyoleuropeins, fraxamoside and frameroside, together with 18 known compounds. Their structures were determined on the basis of spectroscopic studies and chemical evidence.

Cultures of the spore-derived mycobionts of the Asian lichen Pyrenula japonica and the North American species P. pseudobufonia gave two xanthones, 1,5,8-trihydroxy-3-methylxanthone and 1,8-dihydroxy-5-methoxy-3-methylxanthone along with the known 1,7-dihydroxy-3-methylxanthone. Their structures were determined by spectroscopic methods. This is the first instance of the isolation of xanthones with a methyl group at C-3 from lichen mycobionts.

From the dried roots of Cephaelis acuminata, five ipecac alkaloids, neocephaeline, 7′-O-demethylcephaeline, 10-O-demethylcephaeline, 2′-N-(1″-deoxy-1″-β-D-fructopyranosyl)cephaeline and 2′-N-(1″-deoxy-1″-β-D-fructopyranosyl)neocephaeline, were isolated, along with emetine, cephaeline, psychotrine, protoemetine, 9-demethylprotoemetinol and isocephaeline. Structures were determined by spectroscopic and chemical means.