*3.4. Immunosuppressive Activity*

Immunosuppressants are drugs that prohibit body immunity and are principally utilized in organ transplantation to overcome rejection and in auto-immune illnesses [57]. Currently, many immunosuppressive agents act by prohibiting T-cell proliferation; however, there is no new, safe, and efficient immune-suppressive agent that prohibits B-cell proliferation [58].

Dai et al. separated eighteen bergamotane sesquiterpenoids from the EtOAc extract of *Craterellus ordoratus*: craterodoratins A–R (**7**–**11**, **29**–**33**, **53**, **55**, **56**, **63**–**65**, and **71**) and a new victoxinine derivative, craterodoratin S (**42**), along with the previously isolated **5**, **61**, **77**, and **88** by SiO2/RP-18/Sephadex LH-20/preparative HPLC (Figure 6) [30].

**Figure 6.** Structures of tricyclic bergamotane sesquiterpenoids (**56**–**63**).

Their structures with absolute configurations were established by spectral, X-ray diffraction, and ECD analyses and NMR calculations. Compounds **29** and **71** possess a rare skeleton, where the C-14methyl in **71** showed a further 1,2-migration. On the other hand, compounds **7**–**11**, **53**, **55**, **56,** and **63**–**65** belong to β-pinene derivatives that produced **30**–**33** through an alkyl migration (Figure 7). Compounds **7**–**10**, **30**, **42**, **55**, **61**, and **88** demonstrated potent inhibitory potential versus LPS-caused B lymphocyte cell proliferation (IC50s ranged from 0.67 to 22.68 μM) in BALB/c mice compared with cyclosporin A (IC50 of 0.47 μM), where compound **61** (IC50 0.67 μM) had the most potent effectiveness. Moreover, compounds **11** and **61** possessed inhibition (IC50s of 31.50 and 0.98 μM, respectively) on T lymphocyte cells proliferation induced by ConA (concanavalin A) compared with cyclosporin A (IC50 0.04 μM). Structurally, it was noted that the *α*,*β*-unsaturated-carboxylic acid unit could be the key functional group for the immunosuppressive potential of these metabolites. Furthermore, compounds **61** and **7**–**10** with a *β*-pinene main core had a wider range of bioactivities [30].

#### *3.5. Antimicrobial Activity*

From *Podospora decipiens*, two new tetracyclic sesquiterpenoids, decipienolides A (**74**) and B (**75**), were separated from the EtOAc extract by SiO2 CC and HPLC analyses. They were obtained as a mixture of inseparable epimers, having a 3-hydroxy-2,2-dimethylbutyric acid sidechain as elucidated by an NMR analysis (Figure 8). The **74**/**75** mixture had an antibacterial influence versus *B. subtilis* (inhibition zone diameter of 9–10 mm, concentration of 200 μg/disk). Neither of them demonstrated capacity versus *Ascobolus furfuraceus* NRRL6460, *Sordaria fimicola* NRRL6459, and *C. albicans* ATCC90029 [24]. Donacinolides A (**82**) and B (**76**) (concentration of 50 μg/mL) revealed weak inhibition versus *Salmonella enterica* subsp. *enterica* (inhibition rates of 24.3, 23.9, and 26.2%) in the microdilution assay [32]. Furthermore, there were no observed antibacterial activity for purpurolides B (**83**) and C (**84**) (concentration of 50 μM) versus *E. coli* ATCC25922, *M. smegmatis* mc2155 ATCC70084, *S. aureus* ATCC25923, and *S. epidermidis* ATCC12228 [47].

**Figure 7.** Structures of tricyclic bergamotane sesquiterpenoids (**64**–**71**)**.**

**Figure 8.** Structures of tetracyclic bergamotane sesquiterpenoids (**72**–**79**).
