Study on isolation and investigation of antibiotic and cytotoxic activity of secondary compounds from three actinomycetes strains streptomyces g246, g261, g248 collected in some central east Vietnam sea

lation of Streptomyces sp. G248 3.9. Results of bioactivity test of compounds isolated from actinomycete strains 3.9.1. Performance test results for test microorganisms of some isolated compounds Of the 26 substances isolated, we have tested antimicrobial activity. As a result, there are 13 substances with antimicrobial antibiotic activity, many of which have very strong activity such as G246-2, G248-11, G248-12, G248-9 and many substances with good antifungal activity as G246-6, G261-11, G248-11 (see details in table 3.5). 3.9.2. The results of anti-tuberculosis activity test of some isolated compounds The results of tuberculosis resistance testing were performed at UIC University. Some substances tested for anti-tuberculosis activity with Mycobacterium tuberculosis H37Rv, in which G246-1 exhibited the best activity with MIC value of 6.00 µg / ml, G248-10 showed 7 good activity with MIC value = 11.17 µg / ml, while G248-9 showed weak activity with MIC value of 48.02 µg/ ml The remaining substances did not show activity at the study concentration (50 µg/ ml) (see details table 3.6). 3.9.3. Test results of cytotoxic activity of some isolated compounds 14 compounds with tested antimicrobial activity, tuberculosis resistance from three research strains (G246, G261 and G248) were tested for cytotoxic activity with four cancer cell lines in: KB - Schedule cancer tissue (CCL - 17TM); Hep G2 - liver cancer (HB - 8065TM); MCF-7 - breast cancer (HTB - 22TM) and LU-1 - lung cancer (HTB-57TM). The results are detailed in Table 3.5. The result has 5 compounds with cytotoxic activity, including 4 active substances with KB cell line, 5 active compounds with liver cancer cell line Hep-G2, 4 active compounds calculated with Lu-1 cell lines, 4 active compounds with MCF7 cell lines (see details in table 3.7) CHAPTER 4. DISCUSSION OF RESULTS 4.1. Sample collection results A total of 25 samples included: 12 samples in the waters of Thanh Hoa, Quang Binh and Quang Tri; 13 samples in Da Nang and Quang Nam waters. Specifically, there are 10 samples of sediment, 4 samples of seaweed, 4 samples of seaweed, 1 sample of soft corals, 2 samples of echinoderms and 4 other samples. 4.2. Result of isolation of actinomycete strains From 25 samples, 32 isolates with different morphology and colony color were isolated from the collected sample (details are described in Appendix PL III.1.2). 4.3. Results of bioactivity test of strains obtained. - The results of the test of antimicrobial activity with crude scale showed that 29/32 isolated strains are resistant to the strains of test microorganisms. - The results showed that 21/32 strains exhibited anti-tuberculosis activity. - The results showed that 20 strains had toxic activity of KB epithelial cancer cells (IC50 <128 µg / ml). From the results of screening of anti-microbial antimicrobial activity, anti-tuberculosis activity as well as cytotoxic activity (with KB line) in this thesis, I selected 3 isolates with the best activity. for follow-up studies (including actinomycete strains G246, G261, G248). 4.4. Results of identification of bioactive antibiotic strains 4.4.1. Observe morphological characteristics of studied strains 4.4.2. Multiplication of 16S RNA riboxom gene 4.4.3. Solving the gene sequence to identify the name of the actinomycetes 8 Identified the actinomycetes strains G246, G261, G248 all belong to genus Streptomyces sp. (See details at PLIII.1.4) 4.5. The results of high biomass of strains have good biological activity. Successful fermentation of 50 liters for strains G246, G261, G248 to continue the next study. 4.6. Chemical structure of secondary compounds from Streptomyces sp. G246 From the culture fluid of the microorganism strain Streptomyces sp. G246, we isolated and determined the chemical structure of 10 compounds, including 2 new compounds G246-1 and G246-2. The structure of the compounds was determined by NMR, MS spectroscopy methods and compared with reference materials, the compounds were identified as (2S, 2 ″ S) - 6-lavandulyl-7-methoxy-5 , 2 ′, 4′-trihydroxylflavanone (G246-1), (2 ″ S) -5′-lavandulyl-4′- methoxy-2,4,2 ′, 6′-tetrahydroxylchalcone (G246-2), cyclo- ( Pro-Gly (G246-3), cyclo- (L-Pro- L-Tyr) (G246-4), cyclo- (D-Pro-L-Tyr) (G246-5), cyclo- (Pro-Ala) ) (G246-6), norharman (G246-7), tryptophan (G246-8), 3-indol carboxylic acid (G246-9), phenyl alanine (G246-10), including 2 new substances G246-1 and G246-2. The absolute configuration of the two new compounds G246-1 and G246-2 is determined based on the method of calculating quantum circular electron chemistry (ECD) based on Gaussian 09 software. Figure 4.28. Chemical structure of compound G246-1 to G246-10 4.6.1. Compound G246-1: (2S,2″S) -6-lavandulyl-7-methoxy-5,2′,4′-trihydroxylflavanone (new compound) Compound 1 was isolated as an amorphous solid, and optically active [a] 25 D -28(c, 0.8, MeOH). Its positive HR-ESI mass spectrum showed the proton adduct ion [M+H] + at m/z 439.2115 (calcd. for C26H31O6, 439.2121) which, together with 13 C-NMR data, are consistent 9 with the molecular formula of C26H30O6. The IR spectrum showed the presence of hydroxyl (3299 cm -1 ) and carbonyl (1670 cm -1 ) functionalities. In the 1 H-NMR spectrum of 1, the presence of an ABX system at δH 6,35 (1H, d, J = 2.0 Hz, H-3′), 6,37 (1H, dd, J = 2.0, 8.5 Hz, H-5′), 7.31 (1H, d, J = 8.5 Hz, H-6′), and a singlet proton at δH 6.13 was observed in the aromatic region. Additionally, the resonances of protons at dH 5.56, 4.98, 4.54 and 4.59, a methoxy group at dH 3.84, three singlet methyls at δH 1.49, 1.58 and 1.65, and a number of aliphatic protons were noted. Analysis of the 13 C-NMR data with the aid of HSQC experiment revealed 26 carbon resonances for G246-1, including one ketone group (δC 193.9), ten sp 2 quaternary carbons, five sp 2 methines, one sp 2 methylene, two sp 3 methines, three sp 2 methylenes, three methyls and one methoxy group. Beside the aromatic ABX system, two other spin-spin coupling systems were revealed from the COSY spectrum: H-2/CH2-3 (I) and CH2-1”/H-2”/CH2-3”/H-4” (II)). The chemical shifts of carbons at δC 75.5 (C-2), 156.6 (C-20), 159.5 (C-400), 164.9 (C-5), 161.9 (C-7) and 164.9 (C-9) suggested their linkage to oxygen (Table 4.1). In the HMBC spectrum, cross-peaks of C-200 (δC 48.2) with CH3-10” (δH 1.65) and CH2-9” (δH 4.54), and those of C-8” (δC 149.8) with protons of CH2-1” (δH 2.64) indicated the linkage of C-2” of the coupling system II with the isopropenyl group. Furthermore, the HMBC correlations of H-4” (δH 4.98) with C-6” (δC 17.8) and C-7” (δC 25.9), and CH2-3” (δH 2.02) with C-5” (δC 132.0) indicated the lavandulyl group in the structure of G246-1. The presence of the B-ring was confirmed by cross-peaks of H-3’ (δH 6.35) with C-1’ (δC 118.5), C-2’ (δC 156.6), C-4’ (δC 159.5) and C-5’(δC 107.6). Similarly, the A-ring was established by HMBC correlations of H-8 (δH 6.13) with C-6 (δC 109.6), C-7 (δC 161.9), C-9 (δC 164.9) and C-10 (δC 105.7) (Figure 4.1). Figure 4.1. Chemical structure and interactions HMBC (H → C), COSY (H─H) of compound G246-1 and chemical structure of reference compounds. The spectral features of coupling systems I and the carbonyl group deduced from HMBC signals indicated structural similarity of G246-1 to flavanone compounds. The connection of 10 the lavandulyl group to the A-ring at C-6 via C-6/C-1” linkage was revealed by HMBC cross- peaks of the protons of CH2-1” with C-5, C-6 and C-7. Table 4. 1. NMR spectral data of compound G246-1 and reference compound a) measured in CD3OD; b) measured in CD3COCD3; δC # data of sophoraflavanone G compound [89] C C #,b C a H (multi, J, Hz) 2 75,3 75,5 5,56 (dd, 2,5; 13,0) 3 42,8 48,2 2,89 (dd, 13,0; 16,5) 2,71 (dd, 2,5; 16,5) 4 198,2 193,9 5 163,0 164,9 6 96,2 109,6 7 165,3 161,9 8 107,8 93,4 6,13 (s) 9 162,1 164,9 10 103,2 105,7 1′ 117,9 118,5 2′ 156,1 156,6 3′ 103,4 103,4 6,35 (d, 2,0) 4′ 159,4 159,5 5′ 107,8 107,6 6,37 (dd, 2,0; 8,5) 6′ 128,6 128,5 7,31 (d, 8,5) 1′′ 27,7 28,2 2,64 (m) 2′′ 47,8 48,2 2,52 (m) 3′′ 31,9 32,4 2,02 (m) 4′′ 124,5 124,8 4,98 (t, 6,5) 5′′ 131,6 132,0 6′′ 17,9 17,8 1,97 (s) 7′′ 25,8 25,9 1,98 (s) 8′′ 149,1 149,8 9′′ 111,2 111,2 4,54 (s) 4,59 (s) 10′′ 19,1 19,2 1,65 (s) OMe 55,9 3,84 (s) 11 Finally, the methoxy group at δH 3.85 was attached to C-7 as indicated by their correlation in the HMBC spectrum. Complete analyses of 2D-NMR spectra established the structure of G246-1 as 6-lavandulyl-7-methoxy-5,2’,4’-trihydroxylflavanone. Despite extensive effort, attempts to produce suitable crystals of 1 and 2 for X-ray diffraction analysis were unsuccessful. Alternatively, the absolute configurations of G246-1 were resolved by comparison of their experimental and calculated electronic circular dichroism (ECD) spectra. The ECD quantum chemical calculations were performed using the Gaussian 09 software. To obtain minimum energy conformers, geometry optimization of each possible isomer of these compounds was conducted. The calculated ECD spectra of compound G246-1 were generated using the time-dependent density functional method at the B3LYP/6-31++G(d,p) level. Since, the CD spectrum of compound G246-1 displayed a positive Cotton effect at 336nm (Δ +2.98 mdeg) and a negative Cotton effect at 292nm (Δ -9.08 mdeg), the S configuration was thus assigned for carbon C-2 of G246-1 [89]. To determine the absolute configuration of C-2” of G246-1, the ECD spectra of the two isomers, 2S,2”S-1 and 2S,2”R-G246-1, were performed in gas phase. The experimental CD spectrum of G246-1 showed excellent agreement with the calculated ECD of 2S,2”S-G246-1 (Figure 4.1). Thus, the S-configuration was suggested for both C-2 and C-2” of compound G246-1. 4.6.2. Compound G246-2: (2″S)-5′-lavandulyl-4′-methoxy-2,4,2′,6′-tetrahydroxylchalcone (new compound) Figure 4.2. Chemical structure and interactions HMBC (H → C), COSY (H─H) of compound G246-2 and chemical structure of reference compounds. Compound G246-2 was isolated as an optically active [a] 25 D -8.6 (c, 0.25, CH2Cl2). Its HR-ESI-MS showed the proton adduct ion [M+H] + at m/z 439.2115 (calcd. For C26H31O6, 439.2121). A long with the 13 C-NMR data, a molecular formula of C9H8O4 was suggested for G246-2. Comparison of the 1D-NMR spectra with those of G246-1 revealed the same substructures, lavandulyl group, A- and B-ring systems for compound G246-2. The differences were noted for the signals of the CH=CH system [characterized from protons at H 7.82 (d, J = 12 16.0 Hz, H-a) and 7.96 (d, J = 16.0 Hz, H-b)] of G246-2 instead of the resonances of the coupling system CH-2/CH2-3 in the structure of G246-1. Table 4. 1. NMR spectral data of compound G246-2 and reference compound a) measured in CDCl3; b) measured in CD3OD; δC # data of G246-1 compound C# C #,b C C a H (multi, J, Hz) 1′ 118,5 1 116,5 2′ 156,6 2 156,9 3′ 103,4 3 106,2 6,37 (br,s) 4′ 159.5 4 159,1 5′ 107,6 5 109,1 6,43 (br d, 8,0) 6′ 128,5 6 131,0 7,39 (d, 8,0) 10 105,7 1′ 106,2 9 164,9 2′ 161,0 8 93,4 3′ 90,9 5,92 (s) 7 161,9 4′ 161,0 6 109,6 5′ 107,4 5 164,9 6′ 165,8 1′′ 28,2 1′′ 29,7 2,70 (dd, 6,0; 14,0) 2,71 (dd, 8,0; 14,0) 2′′ 48,2 2′′ 46,5 2,39 (m) 3′′ 32,4 3′′ 31,9 2,14 (m) 4′′ 124,8 4′′ 122,8 5,11 (t, 6,5) 5′′ 132,0 5′′ 132,9 6′′ 17,8 6′′ 18,0 1,60 (s) 7′′ 25,9 7′′ 25,8 1,69 (s) 8′′ 149,8 8′′ 150,5 9′′ 111,2 9′′ 110,7 4,76 (s)/ 4,79 (s) 10′′ 19,2 10′′ 20,7 1,72 (s) OH-6′ 14,46 (s) OMe 55,9 OMe 55,7 3,85 (s) 3 48,2 α 126,0 7,82 (d, 16,0) 2 75,5 β 137,5 7,96 (d, 16,0) 4 193,9 γ 193,2 13 This observation suggested a chalcone skeleton for G246-2 which was confirmed by cross-peaks of H-b with C-2 (C 156.9), C-6 (dC 131.0) and C- γ (C 193.2) in the HMBC spectrum of G246-2. The location of the lavandulyl at C-5’ was indicated by the HMBC correlations of CH2-1” (H 2.70 and 2.71) with C-5’ (C 164.9) and C-6’ (C 109.6), and H-2” (H 2.39) with C-6’ (C 109.6) (Figure 4.2). Similarly, HMBC cross-peaks of C-4’ (C 161.0) with the protons of the methoxy at H 3.85 assigned the connection of C-4’ with the methoxy group. Since, a strong coupling constant (J = 16.0 Hz) was noted for H-a and H-b, a trans- configuration was thus assigned for CH-a/CH-b double bond. Complete analyses of the 2D- NMR spectra identified the structure of H246-2 as 5’-lavandulyl-4’-methoxy-2,4,2’,6’- tetrahydroxylchalcone. Despite extensive effort, attempts to produce suitable crystals of G246-2 for X-ray diffraction analysis were unsuccessful. Alternatively, the absolute configurations of G246-2 were resolved by comparison of their experimental and calculated electronic circular dichroism (ECD) spectra. The ECD quantum chemical calculations were performed using the Gaussian 09 software. To obtain minimum energy conformers, geometry optimization of each possible isomer of these compounds was conducted. The calculated ECD spectra of compound G246-2 were generated using the time-dependent density functional method at the B3LYP/6- 31++G(d,p) level. Similarly, the S-configuration was also assigned for compound G246-2 by comparison of its experimental CD spectrum with the calculated ECD spectra (in gas phase) of S- and R-configuration of G246-2. 4.7. Chemical structure of secondary compounds from Streptomyces sp. G261 From the culture fluid of the microorganism strain Streptomyces sp. G261 isolated and determined the chemical structure of 13 compounds: norharman (G261-1), 2,3-butanediol (G261-2), 1H-pyrrole-2-carboxylic acid (G261-3), 2- oxo-2,3-dihydrobenzo [d] oxazole-4- carboxylic acid (G261-4), 3-hydroxy-4-methoxybenzoic acid (G261-5), 2-acetamidobenzamide (G261-6), phenyl alanine (G261-7), cyclo-(Pro-Gly) (G261-8), cyclo- (Pro-Ala) (G261-9), cylo-(Pro-Leu) (G261-10), cyclo-(Pro-Tyr) (G261-11), cyclo-trans-4-OH-(Pro-Phe) (G261- 12), cyclo-(Leu-Tyr) (G261-13), in which 1 substance was first isolated from nature are 2-oxo- 2,3-dihydrobenzo [d] oxazole-4-carboxylic acid (G261-4). Below is a detailed description of the method of determining the structure of compounds G261-4 which is the first compound isolated from nature. 14 Figure 4. 2. Chemical structure of compound G261-1 to G261-13 4.7.1. Compound G261-4: 2-oxo-2,3-dihydrobenzo [d] oxazole-4-carboxylic acid Figure 4.32. Chemical structure and interactions on HMBC spectrum of G261-4 ESI-HRMS mass spectra of G261-4 for the molecular mimic ion peak at m/z 178,0152 [M-H] - (theoretical calculation for molecular formula C8H4NO4 m/z 178,0140). 1 H-NMR spectra show signal appearance of aromatic ring protons in δH 7.24 (1H, d, J = 8.0 Hz, H-7); 7.23 (1H, dd, J = 8.0; 8.0 Hz, H-6); 7.49 (1H, dd, J = 2.0; 7.0 Hz, H-5). 13 C-NMR spectrum in combination with HSQC showed 3 aromatic methine groups at δC 118.1 (C-5); 123.6 (C-7); 126.4 (C-6); and 3 carbon quaternary sp 2 at δC 116.7 (C-4); 144,2 (C-3); 146.5 (C-8); In addition, the presence of a cabonyl group in the low-field region associated with nitrogen allergens at δC 149,2 and a carbonyl group at δC 163.4 was also observed. In HMBC spectrum, there is a long-term interaction of proton H-5 (δH 7.49) with C-4 (δC 116.7); C-3 (δC 144.2) and C = O (δC 163.4) interaction of protons H-7 (δH 7.24) with C-8 ((C 146,5), C-6 (δC 123, 6). Combining spectral data and comparing references [102] allowed the determination of G261-4 as 2-oxo-2,3-dihydrobenzo [d] oxazole-4-carboxylic acid. This is the first compound isolated from nature [103]. 15 4.8. Chemical structure of secondary compounds from Streptomyces sp. G248 From the cultured extract of the Streptomyces sp. G248, by chromatography and spectroscopic methods MS, 1D-NMR, 2D-NMR, isolated and determined the chemical structure of 13 symbol compounds from G248-1 to G248-13 including cyclo-(Pro-Leu) (G248- 1), cyclo-(Pro-Phe) (G248-2), norharman (G248-3), cyclo-(Pro-Tyr) (G248-4), cyclo-(Pro-Gly) (G248-5), cyclo-(Pro-Trp) (G248-6), Adenine (G248-7), 2-(4-hydroxyphenyl) acetic acid (G248-8), (2S,2″S)-6-lavandulyl-7,4′-dimethoxy-5,2′-dihydroxylflavanone (G248-9), (2S) -6- prenyl-4′-methoxy-5,7-dihydroxylflavanone G248-10, (2S,2″S)-6-lavandulyl-5,7,2′,4′- tetrahydroxylflavanone(G248-11), (2″S) -5′-lavandulyl-2′-methoxy-2,4,4′,6′- tetrahydroxylchalcone (G248-12), (2S,2″S)-6-lavandulyl-7-methoxy-5,2′,4′- trihydroxylflavanone (G248-13). Including 3 new compounds are G248-9, G248-11, G248-12 of flavonoids compound. Figure 4.81. Chemical structure of compound G248-1 to G248-13 4.8.1. Compound G248-9: (2S,2″S)-6-lavandulyl-7,4′-dimethoxy-5,2′-dihydroxylflavanone Figure 4. 3. Chemical structure and interactions HMBC (H → C), COSY (H─H) of G248-9 compound and chemical reference structure. 16 Compound G248-9 was isolated as an amorphous solid, and optically active [α]25D = - 5 (c 0.176, MeOH). Its positive HR-ESI mass spectrum showed the proton adduct ion [M+H] + at m/z 453.2270 (calcd for C27H33O6, 453.2277) which, together with 13 C NMR data, is consistent with the molecular formula of C27H31O6. The IR spectrum indicated the presence of hydroxyl groups at 3366 cm -1 , and a carbonyl functionality at 1696 cm -1 . In the 1 H-NMR spectrum, the presence of an ABX system at δH 6.47 (d, J = 2.5 Hz, H-3’), 6.47 (dd, J = 2.0, 8.5 Hz, H-5’) and 7.38 (d, J = 8.5 Hz, H-6’), and a singlet proton at δH 6.12 (s, H-8) was observed at the aromatic region. Additionally, the resonances of protons at H 5.55, 4.96, 4.52 and 4.59, two methoxy groups at H 3.82 and 3.83, three singlet methyls at H 1.48, 1.57 and 1.64, and a number of aliphatic protons were noted. Analysis of 13 C-NMR spectrum with the aid of HSQC experiment revealed 27 carbon resonances for G248-9, including one ketone group (C 193.6), three methyls, one sp 2 methylene, three sp 2 methylenes, five sp 2 methines, two sp 3 methines, two methoxy groups and ten sp 2 quaternary carbons (Table 1). Beside the aromatic ABX system, two other spin-spin coupling systems were revealed from the COSY spectrum: H- 2/CH2-3 (I), and CH2-1’’/H-2’’/CH2-3’’/H-4’’ (II). The chemical shifts of carbons at C 75.0 (C-2), 160.1 (C-2’), 159.0 (C-4’’), 164.7 (C-5), 161.9 (C-7) and 165.4 (C-9) suggested their linkage to oxygen. In the HMBC spectrum, cross-peaks of C-2’’ with CH3-10’’ and CH2-9’’, and those of C-8’’ with protons of CH2-1’’ indicated the linkage of C-2’’ of the coupling system II with the isopropenyl group. Additionally, HMBC correlations of H-4’’ with C-6’’ and C-7’’, and CH2-3’’ with C-5’’ indicated the lavandulyl group in the structure of G248-9. The presence of the A-ring was confirmed by cross-peaks of H-8 with C-6, C-7, C-9 and C-10. Similarly, the B-ring was established by HMBC correlations of H-3’ with C-1’, C-2’, C-4’ and C-5’. The spectral features of coupling systems I and the carbonyl group deduced from HMBC signals indicated structural similarity of G248-9 to flavanone compounds. Furthermore, the connection of the lavandulyl group to the A-ring at C-6 via C-6/C-1’’ linkage was revealed by HMBC cross-peaks of the protons of CH2-1’’ with C-5, C-6 and C-7. Finally, two methoxy group at H 3.82 and 3.83 was attached to C-7 and C-4’ as indicated by their correlation in the HMBC spectrum (Figure 2). Complete analyses of 2D-NMR spectra established the planar structure of G248-9 as 6-lavandulyl-7,4’-dimethoxy-5,2’-dihydroxylflavanone. The G248-9 CD spectrum gives a positive Cotton effect at 336 nm (Δ +2.7) and a negative Cotton effect at 292 nm (Δ - 8.5), allowing for absolute configuration at C- 2 is 2S [89]. The absolute configuration at the C-2 ″ position of G248-9 is determined based on the method of calculating the quantum electron quantum chemistry (ECD - Electronic Circular Dichroism) based on the Gaussian 09 software. The theory for 2S,2″S- and 2S,2″R- allows the 17 determination of 2S, 2″S configurations of G248-9 compound in accordance with the calculation model (Figure 4. 66). Table 4.3. NMR spectral data of compounds G248-9 and compounds refer to G246-1 a) measured in CD3OD; δC # data of G246-1 compound C C #,a C a H (multi, J, Hz) 2 75,5 75,0 5,55 (dd, 2,5; 13,0) 3 48,2 45,4 2,82 (dd, 6,0; 17,0) 2,90 (dd, 13,0; 17,0) 4 193,9 198,8 5 164,9 164,7 6 109,6 109,6 7 161,9 161,9 8 93,4 93,6 6,13 (s) 9 164,9 165,2 10 105,7 105,6 1′ 118,5 119,7 2′ 156,6 160,0 3′ 103,4 99,8 6,49 (d, 2,0) 4′ 159,5 159,0 5′ 107,6 108,1 6,47 (dd, 2,0; 8,0) 6′ 128,5 128,5 7,39 (d, 8,5) 1′′ 28,2 28,2 2,61 (m) 2′′ 48,2 48,2 2,50 (m) 3′′ 32,4 32,4 2,03 m 4′′ 124,8 124,8 4,97 (t, 6,5) 5′′ 132,0 132,0 6′′ 17,8 17,8 1,48 (s) 7′′ 25,9 25,8 1,58 (s) 8′′ 149,8 149,8 9′′ 111,2 111,2 4,53 (m)/ 4,58 (m) 10′′ 19,2 19,1 1,65 (s) OMe 55,9 55,9 3,83 (s) OMe 55,9 3,82 (s) 18 From the analysis on HR-ESI-MS, IR, 1D and 2D NMR spectra, CD and ECD spectrum has been established, the structure of G248-9 is (2S,2″S)-6-lavandulyl-7,4′ -dimethoxy-5.2′- dihydroxylflavanone. Finding on the Scifinder database allows to conclude that this is a new compound. 4.8.2. Compound G248-12: (2″S)-5′-lavandulyl-2′-methoxy-2,4,4′,6′-tetrahydroxylchalcone Figure 4. 4. Chemical structure and interactions HMBC (H → C), COSY (H─H) of G248-12 compound and chemical reference structure. Compound G248-12 was isolated as an amorphous solid, with negative optical rotation [α]25D -1.8 (c 0.54, CH2Cl2) . It’s positive HR-ESI-MS showed the proton adduct ion [M+H] + at m/z 439.2117 (calcd for C26H31O6, 439.2121). Considering the 13 C-NMR data, a molecular formula of C26H30O6 was suggested for G248-11. Comparison of the 1D NMR spectra with those of G248-9 revealed the same substructures, l A- and B-ring systems, avandulyl group for compound G248-12. The differences were noted for the signals of the CH=CH system instead of the resonances of the coupling system CH-2/CH2-3. This observation suggested a chalcone skeleton for G248-12 which was confirmed by cross-peaks of H- with C-2, C-6 and C-γ in the HMBC spectrum of G248-12. The location of the lavandulyl at C-5’ was indicated by the HMBC correlations of H-1’’ with C-5’ (δC 108.9) and C-6’ (δC 166.6), and H-2″ with C-6’ (δC 166.6) (Figure 2). Similarly, HMBC cross-peaks of C-2′ (δC 162.3) with the protons of the methoxy at H 3.91 assigned the connection of C-2’ with the methoxy group. Complete analyses of 2D-NMR spectra established the structure of G248-12 as 5’-lavandulyl-2′- methoxy-2,4,2’,6’-tetrahydroxylchalcone. This compound has the same planar structure of kuraridin, which was previously isolated from Albizzia julibrissin [6]. However, the two compounds have different rotational degrees, so in terms of stereoscopic structure of the compound G248-12 is different from kuraridin (with polarity [α]25D −25.5 (c 0.1, MeOH). Absolutely at position C-2″ of G248-12 is determined based on the method of calculating quantum electron quantum chemistry (ECD - Electronic Circular Dichroism) based on software Gaussian 09. Theoretical calculation for 2 isomers 2″S- and 2″R- allow to determine the configuration 2″S of the compound G248-12 in accordance with the calculation model (Figure 19 4. 76). 1D, 2D-NMR spectrum CD and ECD we identified G248-12 as (2″S)-5′-lavandulyl-2′- methoxy-2,4,4′,6′-tetrahydroxylchalcone. Whether Scifinder allows to conclude this is a new compound. Table 4.4. NMR spectral data of compound G248-12 and reference compound a) measured in CD3OD; # δC, * δC data of reference compound G246-2 and kuraridin [115] C #C a (G246-2) *C a (Kuraridin) C a H (multi, J, Hz) 1 116,5 125,0 124,4 2 156,9 160,3 160,3 3 106,2 103,7 103,7 6,37 (d, 2) 4 159,1 162,4 162,4 5 109,1 108,9 109,0 6,36 (m) 6 131,0 131,6 131,6 7,42 (d, 8,0) 1′ 106,2 108,9 108,8 2′ 161,0 164,0 164,0 3′ 90,9 91,6 91,6 6,02 (s) 4′ 161,0 162,4 162,3 5′ 107,4 116,3 116,2 6′ 165,8 166,6 166,6 1′′ 29,7 28,2 28,2 2,64 (m) 2′′ 46,5 48,0 48,0 2,57 (m) 3′′ 31,9 32,4 32,4 2,10 (m) 4′′ 122,8 125,0 125,0 5,06 (m) 5′′ 132,9 131,8 131,8 6′′ 18,0 17,9 17,9 1,58 (s) 7′′ 25,8 25,9 25,9 1,65 (s) 8′′ 150,5 149,9 149,9 9′′ 110,7 111,1 111,1 4,55 (d, 2,5) 4,61 (dd, 2,5; 1) 10′′ 20,7 19,0 19,0 1,72 (s) OMe 55,7 56,1 56,0 3,91 (s) α 126,0 125,5 125,4 7,96 (d, 16,0) β 137,5 139,8 139,8 8,02 (d, 16,0) γ 193,2 194,8 194,7 20 General remarks on secondary compounds extracted from 3 studied bacteriop