New efficient synthesis of polysubstituted 3,4-dihydroquinazolines and 4H-3,1-benzothiazines through a Passerini/Staudinger/aza-Wittig/addition/nucleophilic substitution sequence

• Long Zhao,
• Mao-Lin Yang,
• Min Liu and
• Ming-Wu Ding

Beilstein J. Org. Chem. 2022, 18, 286–292, doi:10.3762/bjoc.18.32

• -azidobenzaldehyde (1a), benzoic acid (2a) and tert-butyl isocyanide (3a) as the reactants (Scheme 2). When a mixture of 1a, 2a, and 3a in CH2Cl2 was stirred at room temperature for 48 h, the three-component Passerini reaction was carried out smoothly and the azide 4a (R = Ph) was finally obtained in 87% yield

• isocyanates (Table 2, compounds 8a–l, R3 = Ph, 4-ClC6H4, 3-MeC6H4, 4-MeC6H4 and 4-CF3OC6H4) were used, good yields (69–86%) of the products were obtained, whereas moderate yields (54–57%) were obtained when the more steric secondary amines were utilized (Table 2, compound 8m and 8n, NR4R5 = N(Cy)2, N(iPr)2

• dialkylamines were utilized (Table 3, compounds 11l and 11m, NR4R5 = N(Cy)2, N(iPr)2). In cases when phenylmethylamine (compounds 11n and 11o, NR4R5 = N(Ph)Me) was used, 51–56% yields of the products were obtained, but when diphenylamine was used, no product was obtained (compound 11p, NR4R5 = NPh2). Conclusion

Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions

• Surendran Amrutha,
• Sankaran Radhika and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31

• latter with salts of Pd(II) and Co(II) in ethylene glycol and water at pH 11 afforded the desired PdCo nanoparticles-3D graphene nanocomposite. The catalyst was then studied in the Sonogashira coupling reaction of arylacetylenes and aryl halides in the presence of various bases and solvents. The maximum

Anomeric 1,2,3-triazole-linked sialic acid derivatives show selective inhibition towards a bacterial neuraminidase over a trypanosome trans-sialidase

• Peterson de Andrade,
• Sanaz Ahmadipour and
• Robert A. Field

Beilstein J. Org. Chem. 2022, 18, 208–216, doi:10.3762/bjoc.18.24

• were harvested by centrifugation (4,000g, 20 min), re-suspended in lysis buffer (20 Mm Tris/HCl, pH 8.0, EDTA-free protease inhibitor cocktail tablet, 0.02 mg/mL DNaseI). Cell lysis was performed by sonication on ice. Cells were exposed to Amplitude microns of ultrasound every 20 seconds for 10 minutes

• . The recombinant protein was separated from cell debris by centrifugation (20,000g, 30 min). The supernatant was loaded to a 5 mL HisTrapTM HP column (GE healthcare) pre-equilibrated with buffer A (50 mM Tris-HCl, pH 8.0, 150 mM NaCl, 20 mM imidazole) and purified at 4 °C using an ÄKTA pure FPLC system

• (GE Healthcare). The column was washed with buffer A to remove unbound proteins followed by elution of bound proteins with buffer B (50 mM Tris-HCl, pH 8.0, 150 mM NaCl, 500 mM imidazole). Further purification was carried out by gel filtration chromatography (Superdex S200 16/600 column, GE Healthcare

Synthesis and bioactivity of pyrrole-conjugated phosphopeptides

• Qiuxin Zhang,
• Weiyi Tan and
• Bing Xu

Beilstein J. Org. Chem. 2022, 18, 159–166, doi:10.3762/bjoc.18.17

• and 6b for 1, 2, and 3 days. A) TEM images of 1 before and after addition of ALP (0.5 U/mL) in PBS buffer (pH 7.4). Scale bar is 100 nm. Figure 3A was reprinted with permission from [62] https://pubs.acs.org/doi/10.1021/bm5010355, Copyright 2014 American Chemical Society. This content is not subjected

• to CC-BY 4.0. Permission requests related to the material excerpted should be directed to the ACS. B) TEM images of representative pyrrole-conjugated peptides 4a and 6b before and after the addition of ALP (1 U/mL) in PBS buffer (pH 7.4). Scale bar is 200 nm. Molecular structures of the parent

Green synthesis of C5–C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni–chitosan nanocatalyst under ultrasonic conditions

• Soumyadip Basu,
• Sauvik Chatterjee,
• Suman Ray,
• Suvendu Maity,
• Prasanta Ghosh,
• Asim Bhaumik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 133–142, doi:10.3762/bjoc.18.14

• under continuous stirring to a suspension of chitosan (5 g) in 100 mL of water. An ammonia solution was used to adjust the pH value of the mixture to 9. The solution was further stirred continuously overnight at room temperature. After that, the green catalyst was separated by filtration and dried under

Tenacibactins K–M, cytotoxic siderophores from a coral-associated gliding bacterium of the genus Tenacibaculum

• Yasuhiro Igarashi,
• Yiwei Ge,
• Tao Zhou,
• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku and
• Agus Trianto

Beilstein J. Org. Chem. 2022, 18, 110–119, doi:10.3762/bjoc.18.12

• %, Tryptone (Difco Laboratories) 0.5%, dissolved in natural sea water (collected in Toyama Bay, Japan) The pH was adjusted to 7.3 before sterilization. The flasks were shaken at 30 °C for 2 days on a rotary shaker (200 rpm). The seed culture (3 mL) was transferred into 30 500 mL K-1 flasks each containing 100

• mL of A11M production medium (pH 7.0) consisting of 2.5% soluble starch, 0.2% glucose, 0.5% yeast extract, 0.5% Hipolypeptone (Wako Pure Chemical Industries, Ltd), NZ amine (Wako Pure Chemical Industries, Ltd), CaCO3 0.3%, and 1% Diaion HP-20 (Mitsubishi Chemical Co.) in natural sea water. The

1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis

• Ruan Carlos B. Ribeiro,
• Patricia G. Ferreira,
• Amanda de A. Borges,
• Luana da S. M. Forezi,
• Fernando de Carvalho da Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5

• cleaner and form the substitution product at position C4. Fieser and Fieser were the first to study tautomerism between 4-arylamino-1,2-naphthoquinone A and 2-hydroxy-1,4-naphthoquinone-4-arylimine B (Scheme 3C) using the redox potential compared to the pH of the medium. It was observed that

• naphthoquinones A prevail in all pH regions except for extreme acidity, where there is a shift to the form of 2-hydroxy-1,4-naphthoquinone-4-arylimines [73][74]. However, in weakly acidic or alkaline solutions, A is the most stable tautomer (Scheme 3C) [75]. Fragoso and co-workers [76] studied the tautomeric

Stepwise PEG synthesis featuring deprotection and coupling in one pot

• Logan Mikesell,
• Dhananjani N. A. M. Eriyagama,
• Yipeng Yin,
• Bao-Yuan Lu and
• Shiyue Fang

Beilstein J. Org. Chem. 2021, 17, 2976–2982, doi:10.3762/bjoc.17.207

• using the expensive catalyst that was used in the literature [32] due to cost considerations. Another method we tried was to react excess TsO(PEG)4OTs with 2-phenylethan-1-ol under basic conditions to give 2 (Scheme 3). However, separation of 2 from TsO(PEG)4OTs and Ph(CH2)2O(PEG)4O(CH2)2Ph required

• convenience of the one-pot PEG elongation approach. The phenethyl group in 8 was removed with KHMDS and the intermediate alkoxide was reacted directly with 2 in one pot to give the (PEG)20 derivative 9. The same procedure was simply repeated to give PEG derivatives Ph(CH2)2O(PEG)28O(CH2)2Ph (10), Ph(CH2)2O

• (PEG)36O(CH2)2Ph (11), and Ph(CH2)2O(PEG)44O(CH2)2Ph (12). In the PEG elongation process, we used excess KHMDS (2.5 equiv) for the deprotection to overcome inadvertent moisture. To prevent the excess base from deprotecting the phenethyl groups in the monomer, before adding the monomer, the reaction

Study on the interactions between melamine-cored Schiff bases with cucurbit[n]urils of different sizes and its application in detecting silver ions

• Jun-Xian Gou,
• Yang Luo,
• Xi-Nan Yang,
• Wei Zhang,
• Ji-Hong Lu,
• Zhu Tao and
• Xin Xiao

Beilstein J. Org. Chem. 2021, 17, 2950–2958, doi:10.3762/bjoc.17.204

• was concentrated under vacuum and then acidified by HCl to pH 2 to precipitate a white solid. 1H NMR (D2O) δ 9.52 (s, 3H), 7.68 (d, 6H), 6.89 (d, 6H), 3.98 (t, 6H), 1.90 (t, 6H), 1.92 (m, 6H) ppm. The 1H NMR titration of TBT (1 mM) with an increasing amount of TMeQ[6] from 0 (i), 0.1 (ii), 0.2 (iii

Unsaturated fatty acids and a prenylated tryptophan derivative from a rare actinomycete of the genus Couchioplanes

• Shun Saito,
• Kanji Indo,
• Naoya Oku,
• Hisayuki Komaki,
• Masashi Kawasaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2939–2949, doi:10.3762/bjoc.17.203

• extract 0.5%, and glucose 0.2% (pH 7.3) solidified by agar 2%, was inoculated into test tubes (inner diameter, 15 mm; length 16.5 cm) each containing 5 mL of YG seed medium consisting of glucose 1% and yeast extract 1% (pH 7.0). The tubes were shaken at 260 strokes/min at 28 °C for 3 days (TC-500R

• days. Isolation of compounds 1–5 Compounds 1–5 were obtained from a culture fermented in A16 production medium with a composition of glucose 2%, Pharmamedia® (Traders Protein, Memphis, TN, USA) 1%, and CaCO3 0.5%. The pH of the medium was adjusted to 7.0 before autoclaving. At the end of fermentation

• , 221.1148; found, 221.1149. Isolation of 6 Compound 6 was obtained from a culture fermented in modified V22 production medium with a composition of soluble starch 1%, glucose 0.5%, NZ Amine, Type A 0.3%, yeast extract 0.2%, Tryptone 0.5% K2HPO4 0.1%, MgSO4·7H2O 0.05%, and CaCO3 0.3%. The pH of the medium

A photochemical C=C cleavage process: toward access to backbone N-formyl peptides

• Haopei Wang and
• Zachary T. Ball

Beilstein J. Org. Chem. 2021, 17, 2932–2938, doi:10.3762/bjoc.17.202

• studies into this reaction demonstrate two mechanistically distinct photocleavage pathways, with selectivity dependent on pH. In addition to an anticipated alkenyl sp2 C–X bond cleavage pathway, we identified a new photochemical reaction pathway, prevalent under neutral and acidic reaction conditions

• at pH 4.0 provided a mixture of methanol (53%) and methyl formate (38%, 7) as determined by NMR, the latter product is the result of formal oxidative C=C cleavage (Figure 3a). Alkenyl amide 1 at pH 4.0 similarly gave mixtures of the C–N cleavage product 2 and C=C cleavage product 8. We examined

• product selectivity in the irradiation of alkenyl amide 1 across a range of pH and found a significant correlation (Figure 3b–d). The formyl product 8 predominated at acidic and neutral pH. The amount of 8 decreased with increasing pH, and above pH 10 the C–X cleavage product 2 became the major product

Host–guest interaction and properties of cucurbit[8]uril with chloramphenicol

• Lin Zhang,
• Jun Zheng,
• Guangyan Luo,
• Xiaoyue Li,
• Yunqian Zhang,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2021, 17, 2832–2839, doi:10.3762/bjoc.17.194

• variation of the UV absorption intensity of CPE and CPE@Q[8] over time in simulated gastric juice (pH 1.2). Figure 7B shows the relationship between the UV absorption intensity of CPE and its inclusion complex in artificial intestinal fluid (pH 6.8) with time. The results show that CPE itself has high

• 1.3 h in artificial gastric juice (pH 1.2) and its release rate was 88.19%. CPE@Q[8] basically reached a release equilibrium after 9 h and the cumulative release rate was 51.26%. It is possible that the inclusion of CPE in Q[8] causes its release rate to be reduced and has a slow-release effect. In

• for Q[8] (a), CPE (b), a physical mixture of Q[8] and CPE (c), and the CPE@Q[8] inclusion complex (d). UV absorption intensity of CPE and CPE@Q[8] changes with time in the artificial gastrointestinal juice (pH 1.2, pH 6.8). Release curve of CPE and CPE@Q[8] in artificial gastrointestinal juice (pH 1.2

Biological properties and conformational studies of amphiphilic Pd(II) and Ni(II) complexes bearing functionalized aroylaminocarbo-N-thioylpyrrolinate units

• Samet Poyraz,
• Samet Belveren,
• Sabriye Aydınoğlu,
• Mahmut Ulger,
• Abel de Cózar,
• Maria de Gracia Retamosa,
• Jose M. Sansano and
• H. Ali Döndaş

Beilstein J. Org. Chem. 2021, 17, 2812–2821, doi:10.3762/bjoc.17.192

• Ankara, Turkey) with respect to the standard document (M27-A2) of NCCLS [33]. As a reference antifungal agent fluconazole (Sigma, F8929) was used (Table 2). As mentioned in the M27-A2 document, experiments were performed in RPMI 1640 medium adjusted to pH 7.0 with 0.165 M 3-(N-morpholino)-propane

Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases

• Inaiá O. Rocha,
• Yuri G. Kappenberg,
• Wilian C. Rosa,
• Clarissa P. Frizzo,
• Nilo Zanatta,
• Marcos A. P. Martins,
• Isadora Tisoco,
• Bernardo A. Iglesias and
• Helio G. Bonacorso

Beilstein J. Org. Chem. 2021, 17, 2799–2811, doi:10.3762/bjoc.17.191

• -yl)imino)methyl)phenols 3, was easily synthesized with yields of up to 91% from the reactions involving a series of 2-(R-substituted) 6-amino-4-(trifluoromethyl)quinolines 1 and 4(5)-R1-substituted salicylaldehydes 2 – in which alkyl/aryl/heteroaryl for 2-R-substituents are Me, Ph, 4-MeC6H4, 4-FC6H4

• substituent or polarity of the solvent (behavior in CHCl3, MeOH, and DMSO is quite similar). Notably, one can highlight compound 3bb (R = Ph, R1 = 5-NEt2) which transitions vary significantly with the change in polarity of the medium (4–24 nm), and this may be due to the donor diethylamino group attached to

• fluorescence yields (Φf) were calculated in order to prove the quantum efficiency of these derivatives in terms of fluorescence emission and thus discuss the influence of the different solvents and substituents. Firstly, by comparing the selected solvents, compound 3aa (R = Ph, R1 = H) presented an emission in

The ethoxycarbonyl group as both activating and protective group in N-acyl-Pictet–Spengler reactions using methoxystyrenes. A short approach to racemic 1-benzyltetrahydroisoquinoline alkaloids

• Marco Keller,
• Karl Sauvageot-Witzku,
• Franz Geisslinger,
• Nicole Urban,
• Michael Schaefer,
• Karin Bartel and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2716–2725, doi:10.3762/bjoc.17.183

• adjusted to pH 9 with NaOH or neutral as mobile phase. Details of the syntheses and spectroscopic data are presented in Supporting Information File 1. Fluorometric Ca2+ measurements Concentration–response curves of 1-benzyltetrahydroisoquinolines were generated by using a custom-made fluorescence imaging

• ) suspensions were loaded with 4 µM fluo-4/AM (Life Technologies, Eugene, OR) for 30 min at 37 °C. After centrifugation, cells were resuspended in HEPES-buffered saline (HBS), containing 132 mM NaCl, 6 mM KCl, 1 mM MgCl2, 1 mM CaCl2, 10 mM HEPES, and 5.5 mM ᴅ-glucose (pH was adjusted to 7.4 with NaOH) and

Synthetic strategies toward 1,3-oxathiolane nucleoside analogues

• Umesh P. Aher,
• Dhananjai Srivastava,
• Girij P. Singh and
• Jayashree B. S

Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182

• a catalyst for the asymmetric preparation of a chiral intermediate of the antiviral agent lamivudine (1, Scheme 23). Further, the reaction conditions were optimized, and a series of factors was explored, including pH value, concentration, temperature, as well as the presence of metal ions and

• surfactant. Exceptionally, the end product was obtained in 99.9% ee by using whole-cell Klebsiella oxytoca catalysis and enantioselective resolution of the racemic mixture at 30 °C, pH 7.0, a substrate concentration of 1.5 g/L, and no additives. As compared to nearly all of the lipase-catalyzed methods to

N-Sulfinylpyrrolidine-containing ureas and thioureas as bifunctional organocatalysts

• Viera Poláčková,
• Dominika Krištofíková,
• Boglárka Némethová,
• Renata Górová,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2021, 17, 2629–2641, doi:10.3762/bjoc.17.176

• . Then, the solvent was removed under vacuum and the pH of the residue was adjusted to around 2 with 1 M HCl. The aqueous phase was washed with Et2O (3 × 25 mL). The pH of the aqueous phase was adjusted to 13 with 2 M NaOH, and extracted with DCM (6 × 20 mL). The organic phase was dried with Na2SO4 and

Synthesis of new bile acid-fused tetrazoles using the Schmidt reaction

• Dušan Đ. Škorić,
• Olivera R. Klisurić,
• Dimitar S. Jakimov,
• Marija N. Sakač and
• János J. Csanádi

Beilstein J. Org. Chem. 2021, 17, 2611–2620, doi:10.3762/bjoc.17.174

• (10 mL, 5% w/v). The reaction mixture was stirred at room temperature for 24 h. After reaction completion the mixture was concentrated in vacuo and poured into water. Then, the pH value was adjusted to ≈3 with 1 M HCl. The mixture was extracted with ethyl acetate, and the combined organic extracts

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• -arylnitroolefins 101 and the best results (yield 99%, ee 91%) were obtained in the reaction of benzylamine (R1 = Ph) on using the NHC precursor as shown below in the presence of hexafluoroisopropanol (HFIP) as additive along with molecular sieves (4 Å) (Table 23) [63]. The role of HFIP is to act as proton shuttle

α-Ketol and α-iminol rearrangements in synthetic organic and biosynthetic reactions

• Scott Benz and
• Andrew S. Murkin

Beilstein J. Org. Chem. 2021, 17, 2570–2584, doi:10.3762/bjoc.17.172

• with greater than 80% ee. As a third example of an enantioselective α-ketol rearrangement, Dai et al. used a chiral Al(III) catalyst to induce the rearrangement of 3 (Ar = Ph) and several aryl derivatives 9 (Figure 4) [6]. Among the N,N′-dioxide ligands explored, 11, which was derived from ʟ

• episilvestrol (35), natural products with potent anticancer properties. The step prior to the rearrangement involved a photoinduced [3 + 2] cycloaddition between hydroxyflavone 36 and methyl cinnamate (37), resulting in the bicyclic α-ketol 38 as a mixture of diastereomers (Ph and CO2Me groups trans) (Figure 9

• later explored alternative Brønsted and Lewis acids that could effectively catalyze the rearrangement of symmetric α‑hydroxy aldimines [29]. A catalyst screen was performed on the model substrate 97a (97 with R = Ph; Figure 19a) using three different Brønsted acids (acetic acid, sulfuric acid, and p

Cryogels: recent applications in 3D-bioprinting, injectable cryogels, drug delivery, and wound healing

• Luke O. Jones,
• Leah Williams,
• Tasmin Boam,
• Martin Kalmet,
• Chidubem Oguike and
• Fiona L. Hatton

Beilstein J. Org. Chem. 2021, 17, 2553–2569, doi:10.3762/bjoc.17.171

• Stimuli-responsive properties are often desirable for biomaterials used in drug-delivery applications. Here, we focus on temperature and solution pH response of cryogels as detailed below. 3.1. Temperature-responsive cryogels This is a property which can easily be applied and manipulated through careful

• [11][33][39]. Thermoresponsive cryogels comprising oligoethylene glycol have also been reported with dual shape memory behaviour [40]. Natural polymers such as cellulose derivatives, chitosan, gelatin, and dextran exhibit temperature-responsive properties and have been used in cryogels. 3.2. pH

• -Responsive cryogels The degree of swelling is affected by the chemical composition of the cryogel, and the nature of the medium, such as pH, ionic strength, and swelling medium composition [34][41]. This affects the interactions of pH-sensitive polymers (both polymer–solvent and polymer–polymer interactions

Silica gel and microwave-promoted synthesis of dihydropyrrolizines and tetrahydroindolizines from enaminones

• Robin Klintworth,
• Garreth L. Morgans,
• Stefania M. Scalzullo,
• Charles B. de Koning,
• Willem A. L. van Otterlo and
• Joseph P. Michael

Beilstein J. Org. Chem. 2021, 17, 2543–2552, doi:10.3762/bjoc.17.170

• described in this article. Results and Discussion The benzoyl-containing enaminone 15a (Ar = Ph) was selected as a model for investigating conditions for the cyclization. This compound was conveniently prepared by Eschenmoser sulfide contraction [29][30], as shown in Scheme 2. The route entailed initial

• N-phenacyl analogue 11 (Ar = Ar’ = Ph), the ester-containing enaminone 15a proved to be completely stable during chromatography on silica gel or upon dissolution in acetic acid at room temperature (conditions under which we had observed cyclization of vinylogous amides 11 [18]), and spontaneous

Direct C(sp³)–H allylation of 2-alkylpyridines with Morita–Baylis–Hillman carbonates via a tandem nucleophilic substitution/aza-Cope rearrangement

• Siyu Wang,
• Lianyou Zheng,
• Shutao Wang,
• Shulin Ning,
• Zhuoqi Zhang and
• Jinbao Xiang

Beilstein J. Org. Chem. 2021, 17, 2505–2510, doi:10.3762/bjoc.17.167

• substituents, the reactions of the MBH carbonates with H or alkyl groups were also investigated. For the carbonate with R = H, the reaction worked pretty well to give the mono-allylic product 3j in 84% yield. However, when R = Ph(CH2)2- as an example, a longer reaction time was needed and the product 3k was

• , respectively). However, the reaction of 2,4-lutidine with 2a led to complex results with several indistinct by-products formed, and only 39% yield of the desired product 4a was isolated. The R2 group on the 2-alkylpyridines were then investigated. When R2 = Me or Ph, the reactions also proceeded well

Efficient synthesis of polyfunctionalized carbazoles and pyrrolo[3,4-c]carbazoles via domino Diels–Alder reaction

• Ren-Jie Fang,
• Chen Yan,
• Jing Sun,
• Ying Han and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2021, 17, 2425–2432, doi:10.3762/bjoc.17.159

• ]carbazoles 4a–l in satisfactory yields. Indole itself and N-methylindole could also be successfully employed in the reaction. The N–Me, N–Ph, and N–Bn substitution in the maleimide moiety showed only a marginal effect on the reaction outcome. Various chalcones with electron-donating methyl and methoxy groups

Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

• Emmanuel T. Oluwabusola,
• Olusoji O. Adebisi,
• Fernando Reyes,
• Kojo S. Acquah,
• Mercedes De La Cruz,
• Larry L. Mweetwa,
• Joy E. Rajakulendran,
• Digby F. Warner,
• Deng Hai,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2021, 17, 2390–2398, doi:10.3762/bjoc.17.156

• Erlenmeyer flask containing 150 mL modified SGG medium (glycerol 10 g, corn steep powder 2.5 g, peptone 5 g, soluble starch 10 g, yeast extract 2 g, CaCO3 3 g, NaCl 1 g, in 1 L H2O, pH adjusted to 7.3) [45]. The flask was left shaking at 160 rpm in a closed system shaker for ten days at 28 °C. Subsequently