Transformation of the cyclohexane ring to the cyclopentane fragment of biologically active compounds

• Natalya Akhmetdinova,
• Ilgiz Biktagirov and
• Liliya Kh. Faizullina

Beilstein J. Org. Chem. 2025, 21, 2416–2446, doi:10.3762/bjoc.21.185

• , derivatives of cholesterol 171a,b,c,d, diosgenin 172a,b, pregnenolone 173–175, dehydroepiandrosterone 176, 177a,b, and azasteroids 178a,b, 179, in the form of single diastereomers (Table 2 and Figure 2) [85]. In the five-step synthesis of artalbic acid (180), the authors [85] used a photoinduced carboborative

Recent advances in Norrish–Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis

• Peng-Xi Luo,
• Jin-Xuan Yang,
• Shao-Min Fu and
• Bo Liu

Beilstein J. Org. Chem. 2025, 21, 2315–2333, doi:10.3762/bjoc.21.177

• –Yang cyclization and the divergent starting point for accessing the other eight natural products (50–57). As an initial lead, two commercially available starting materials: (−)-citronellal (58) and diosgenin were employed (Scheme 7). (–)-Citronellal (58) was first converted to 59 via enantioselective

• intramolecular aldehyde α-alkylation using MacMillan's protocol, subsequently undergoing Shi's asymmetric epoxidation to give rise to epoxide 60 as a 3:1 mixture of diastereomers. These were not separated until step 8 due to poor separability at this stage. Concurrently, diosgenin was then processed through a

Cytochrome P450 monooxygenase-mediated tailoring of triterpenoids and steroids in plants

• Karan Malhotra and
• Jakob Franke

Beilstein J. Org. Chem. 2022, 18, 1289–1310, doi:10.3762/bjoc.18.135

• versatility of CYPs in plant triterpenoid and steroid metabolism (Figure 6). Diosgenin (13) is a specialised plant natural product with a unique 5,6-spiroketal moiety that serves as an inexpensive raw material for the industrial synthesis of steroidal drugs. Diosgenin (13) biosynthesis from cholesterol (3

• oxidative ring closure, leading to a hemiketal bridge between C16 and C22. Following these initial hydroxylations, CYPs from multiple families catalyse end-of-chain hydroxylation at C27 which is followed by spontaneous spiroketalisation to form diosgenin (13). The CYP pairs PpCYP90G4-PpCYP94D108 in P

• . polyphylla and TfCYP90B50-TfCYP82J17 in T. foenum-graecum resulted in the highest diosgenin (13) production. Diosgenin (13) biosynthesis in distantly related plants is an example of catalytic plasticity embedded within the ancient CYP90Bs. Especially CYPs from large families often show high substrate

Diosgenyl 2-amino-2-deoxy-β-D-galactopyranoside: synthesis, derivatives and antimicrobial activity

• Henryk Myszka,
• Patrycja Sokołowska,
• Agnieszka Cieślińska,
• Andrzej Nowacki,
• Maciej Jaśkiewicz,
• Wojciech Kamysz and
• Beata Liberek

Beilstein J. Org. Chem. 2017, 13, 2310–2315, doi:10.3762/bjoc.13.227

• the obtained compounds are active against Gram-positive bacteria and Candida type fungi. Keywords: antimicrobial activities; D-galactosamine; diosgenin; glycosylation; saponin; tetrachlorophthalimido derivatives; Introduction Saponins are steroid or triterpenoid glycosides found in various plants [1

• , particularly antifungal [3][4][5][6] and antitumor [7][8][9]. The aglycone part of a saponin is termed sapogenin. Diosgenin, yamogenin, tigogenin, smilagenin and sarsapogenin are the most abundant sapogenins in nature [10]. They are linked via a glycosidic bond to a sugar unit, mainly D-glucose. Diosgenyl

• glycosides constitute a very important group among spirostanol saponins. Diosgenin has a double bond between the C-5 and C-6 atoms of the spirostanol skeleton and can be found in combination with different sugars in Costus, Discorea, Paris, Solanum, Yucca, and Trillium plants [11]. The plants containing

N-Alkyl derivatives of diosgenyl 2-amino-2-deoxy-β-D-glucopyranoside; synthesis and antimicrobial activity

• Agata Walczewska,
• Daria Grzywacz,
• Dorota Bednarczyk,
• Małgorzata Dawgul,
• Andrzej Nowacki,
• Wojciech Kamysz,
• Beata Liberek and
• Henryk Myszka

Beilstein J. Org. Chem. 2015, 11, 869–874, doi:10.3762/bjoc.11.97

• . Keywords: antimicrobial activities; D-glucosamine; diosgenin glycosylation; N-alkylation; Introduction Saponins are a group of steroid or triterpenoid glycosides, widely distributed in the plant kingdom [1]. Saponins are characteristic by their foaming properties in aqueous solution, causing them to be

• diosgenin. Very often this D-glucopyranose is substituted with α-L-rhamnopyranose at 2-OH and other sugars at 4-OH. The change of D-glucopyranose into 2-amino-2-deoxy-D-glucopyranose provides diosgenyl 2-amino-2-deoxy-β-D-glucopyranoside (7), a synthetic saponin, first reported by us [39]. It was also

• -hydroxy derivatives of D-glucose and L-rhamnose [49]. Glycosylation of diosgenin with twelve different derivatives of D-glucosamine (2a–d, 3a–d, and 5a–d), was examined using “normal” and “reverse” procedures [50] (Table 1). In the “normal” procedure, the promoter (silver triflate or trimethylsilyl