Dynamic behavior of rearranging carbocations – implications for terpene biosynthesis

• Stephanie R. Hare and
• Dean J. Tantillo

Beilstein J. Org. Chem. 2016, 12, 377–390, doi:10.3762/bjoc.12.41

• in the pimar-15-en-8-yl cation can lead to a PTSB – one branch of which leads to the carbocation precursor to abietadiene (Figure 9, green), but the other branch of which leads to a rearranged skeleton, not yet reported for any diterpenes/diterpenoids from Nature (Figure 9, red). Interconversion of

Genicunolide A, B and C: three new triterpenoids from Euphorbia geniculata

• Alia Farozi,
• Javid A. Banday and
• Shakeel A. Shah

Beilstein J. Org. Chem. 2015, 11, 2707–2712, doi:10.3762/bjoc.11.291

• plants to well developed tall trees [1]. The plants of the family Euphorbiaceae contain well-known skin irritating and tumor-promoting diterpenoids with tigliane, ingenane and daphnane skeletons [2]. Some of the species are used in folk medicine to cure skin diseases, gonorrhea, migraines, intestinal

• parasites, and warts [3] and as a purgative [4][5][6]. Several macrocyclic diterpenoids with antibacterial, anticancer, anti-multidrug-resistant, antifeedant, anti-HIV and analgesic activity have been isolated from different Euphorbia species. They include jatrophane, ingol and myrsinane diterpenoids [7][8

Synthesis of Xenia diterpenoids and related metabolites isolated from marine organisms

• Tatjana Huber,
• Lara Weisheit and
• Thomas Magauer

Beilstein J. Org. Chem. 2015, 11, 2521–2539, doi:10.3762/bjoc.11.273

• Tatjana Huber Lara Weisheit Thomas Magauer Department of Chemistry and Pharmacy, Ludwig-Maximilians-University Munich, Butenandtstraße 5–13, 81377 Munich, Germany 10.3762/bjoc.11.273 Abstract This review describes strategies for the chemical synthesis of xenicane diterpenoids and structurally

• nine-membered carbocycle which is the characteristic structural feature of these natural products. Additionally, the putative biosynthetic pathway of xenicanes is illustrated. Keywords: asymmetric synthesis; natural products; total synthesis; Xenia diterpenoids; xenicanes; Introduction Terpenoids are

• a large group of structurally diverse secondary metabolites. Among these natural products, Xenia diterpenoids or xenicanes represent a unique family with intriguing structural features and diverse biological activities. Many xenicanes display significant cytotoxic and antibacterial activity and are

Recent highlights in biosynthesis research using stable isotopes

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2015, 11, 2493–2508, doi:10.3762/bjoc.11.271

• performed to investigate the mechanisms for intermedeol and neomeranol B biosynthesis [62]. Cyclooctat-9-en-7-ol (52), a member of the fusicoccane family of diterpenoids, is the biosynthetic precursor of cyclooctatin (45) [63], a potent inhibitor of lysophospholipase, which was isolated from Streptomyces

Trogopterins A–C: Three new neolignans from feces of Trogopterus xanthipes

• Soyoon Baek,
• Xuikui Xia,
• Byung Sun Min,
• Chanil Park and
• Sang Hee Shim

Beilstein J. Org. Chem. 2014, 10, 2955–2962, doi:10.3762/bjoc.10.313

• neolignans 1–3, a norlignan 4, and three diterpenoids 5–7, were isolated from the feces of Trogopterus xanthipes. Structures of these compounds were identified by 1D and 2D NMR as well as MS. The absolute configurations of compounds 1, 2, and 4 were determined by comparing CD spectra and optical rotations

• three diterpenoids (5–7), were isolated from the methanolic extract of T. xanthipes feces. Their chemical names are methyl 3-((2S,3R)-7-hydroxy-2-(3-hydroxy-4-methoxyphenyl)-3-(hydroxymethyl)-2,3-dihydrobenzofuran-5-yl)propanoate (1), (S)-methyl 3-(3-hydroxy-5-(1-hydroxy-3-(3-hydroxyphenyl)propan-2-yl

Aspergiloid I, an unprecedented spirolactone norditerpenoid from the plant-derived endophytic fungus Aspergillus sp. YXf3

• Zhi Kai Guo,
• Rong Wang,
• Wei Huang,
• Xiao Nian Li,
• Rong Jiang,
• Ren Xiang Tan and
• Hui Ming Ge

Beilstein J. Org. Chem. 2014, 10, 2677–2682, doi:10.3762/bjoc.10.282

• previous chemical investigation of the bioactive secondary metabolites produced by the endophytic Aspergillus sp. YXf3 associated with Ginkgo biloba led to the isolation of new p-terphenyls and novel types of diterpenoids including pimarane-type diterpenoids (sphaeropsidins A and B, aspergiloids D and E

• ), a cleistanthane-type diterpenoid (aspergiloid C), and norcleistanthane-type diterpenoids (asergiloids A, B, and F–H), many of which were reported from this microorganism for the first time [7][8][9]. Interestingly, sphaeropsidins A and B were also discovered from both Aspergillus chevalieri and

• -unsaturated spirolactone moiety in ring B. The skeleton, tentatively named aspergilane, represents a new subclass of norditerpenoids. The endophytic fungus Aspergillus sp. YXf3 can produce different types of diterpenoids, including pimarane-type diterpenoids (sphaeropsidin A and B, aspergiloid D and E

Decandrinin, an unprecedented C₉-spiro-fused 7,8-seco-ent-abietane from the Godavari mangrove Ceriops decandra

• Hui Wang,
• Min-Yi Li,
• Félix Zongwe Katele,
• Tirumani Satyanandamurty,
• Jun Wu and
• Gerhard Bringmann

Beilstein J. Org. Chem. 2014, 10, 276–281, doi:10.3762/bjoc.10.23

• , five kauranes, and 16 lupanes). Recently, some of us have reported on the isolation of eleven new diterpenes from this plant, named decandrins A–K [7], of which nine belong to the group of abietanes. Seco-abietane diterpenoids are a small group of natural products. To date, a total of 58 such compounds

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• to frondosin B (99) in three steps according to Danishefsky and co-workers [95][96]. The groups of Davies and Sarpong [97] teamed up for the total syntheses of the diterpenoids barekoxide (106, see Scheme 13) [98] and barekol (107) [99], isolated from the sponges Chelonaplysilla erecta and Raspailia

The volatiles of pathogenic and nonpathogenic mycobacteria and related bacteria

• Thorben Nawrath,
• Georgies F. Mgode,
• Bart Weetjens,
• Stefan H. E. Kaufmann and
• Stefan Schulz

Beilstein J. Org. Chem. 2012, 8, 290–299, doi:10.3762/bjoc.8.31

• produced by N. africana, it was also present in the bouquet of an early culture of N. asteroides (Table 6). Additionally, both bacteria produced several unknown diterpenoids. Such relatively large compounds have rarely been reported as bacterial volatiles [33][34]. In additional experiments, a Sauton

Carbamate derivatives and sesquiterpenoids from the South China Sea gorgonian Melitodes squamata

• Li-Si Huang,
• Fei He,
• Hui Huang,
• Xiao-Yong Zhang and
• Shu-Hua Qi

Beilstein J. Org. Chem. 2012, 8, 170–176, doi:10.3762/bjoc.8.18

• , diterpenoids, prostanoids, and steroids [1][2]. However, nitrogen-containing compounds were relatively few obtained from gorgonians. Gorgonian Melitodes squamata Nutting belonging to Melithaea family is a kind of pharmaceutical coral that has the efficacy of relieving cough, bleeding, and diarrhea, soothing

Studies on polynuclear furoquinones. Part 1: Synthesis of tri- and tetra- cyclic furoquinones simulating BCD/ABCD ring system of furoquinone diterpenoids

• Faruk H. Shaik and
• Gandhi K. Kar

Beilstein J. Org. Chem. 2009, 5, No. 47, doi:10.3762/bjoc.5.47

• ], antioxidant and anti-inflammatory agent [12][13][14] as well as induces apoptosis in human leukemia cell lines [15][16]. It is believed that broad spectrum of activities of Dan Shen are mainly associated with the presence of tetra cyclic furoquinone diterpenoids like Tanshinone I [17][18], Tanshinone IIA and

• diterpenoids have been reported in literature [18][19][20][21][22][23][24][25][26][27] in the last few decades. In comparison only very few syntheses of tricyclic furoquinone 18 [29][30] and its derivatives [31][32][33] have been reported. Encouraged by the broad spectrum biological activity of furoquinones