Science and Technology Development Journal - Natural Sciences 2022-08-15T03:37:09+00:00 Phuc Van Pham Open Journal Systems Aristolactame and aporphine alkaloid from the ethyl acetate extract of stems Melodorum fruticosum L. 2022-07-20T13:41:40+00:00 Hương Thị Mỹ Nguyễn Liên Thị Mỹ Đỗ <p>Melodorum fruticosum (Annonaceae), a shrub with fragrant yellow flowers, distributed in South East Asia, more specifically indigenous to Thailand, Laos, Cambodia, and Vietnam. In Vietnam, M. fruticosum has been used as folk medicine remedies for the treatment of digestive diseases, abdominal dyspepsia in women after giving birth. This plant has been used as a tonic, a mild cardiac stimulant, antipyretics and as a hematinic to resolve dizziness by Thai people. The essential oil of M. fruticosum flowers is used in aromatherapy and as traditional medicines in Thailand. Its flowers and barks have been reported to have antifungal, antioxidant, and cytotoxic activities. Phytochemical investigation on the fractions EA.3 and EA.4 from the ethyl acetate extract of stem of M. fruticosum led to the isolation of five alkaloids including aristolactame AII (1), goniopedalin (2), piperolactame C (3), 10-amino-3,6-dihydroxy-2,4-dimethoxyphenanthrene-1-carboxylic acid (4) and noraristolodione (5). Their chemical structures were elucidated by 1D and 2D–NMR, ESI-MS as well as compared with data in the literatures. All these compounds were isolated for the first time from the M. fruticosum collected at Di Linh district, Lam Dong province, Vietnam. All isolated were evaluated for their cytotoxicity against KB, Hep-G2, and MCF-7 cell lines. Among them, compound (2) showed weak cytotoxicity against the tested cell lines.</p> 2022-07-20T13:41:39+00:00 ##submission.copyrightStatement## Six flavonoids from the ethyl acetate extract of the pericarp of Garcinia schomburgkiana 2022-08-09T20:34:44+00:00 Trí Hữu Nguyễn Tuyết Thị Ánh Nguyễn Lien Thi-My Do <p>Garcinia is a genus of Clusiaceae, distributed throughout tropical Asia, Africa, New Caledonia, Polynesia, and Brazil. In traditional medicine, the fruits of Garcinia have been utilized in infusions for treating wounds, ulcers, and dysentery. Extracts of the pericarp and seeds of Garcinia have demonstrated antioxidant, anti-inflammatory, leishmanicidal, and antiprotozoal activities. Garcinia plants contained a broad range of biologically active metabolites which, in the last few decades, have received considerable attention due to the chemical compositions of their extracts, with compounds possessing beneficial effects in several diseases. These species provide a rich natural source of bioactive compounds with relevant therapeutic properties and anti-inflammatory effects, such as flavonoid, xanthone, biflavonoid, biphenyl derivaties, and benzophenone. This paper demonstrated the relevance of the genus as a rich source of compounds with valuable therapeutic properties, with potential use in the prevention and treatment of nontransmissible chronic diseases. Phytochemical investigation on the fraction EA4 from the ethyl acetate extract of the pericarp Garcinia schomburgkianna led to the isolation of six flavonoid compounds such as quercetin (1), kaempferol (2), luteolin (3), cirsiliol (4), quercetin 3-O-β-D-glucopyranoside or isoquercetin (5) and quercetin 3-O-α-L-rhamnopyranoside (6). Their chemical structures were elucidated by 1D, 2D–NMR as well as compared with the literatures. Compounds (1), (3), (4), (5), (6). were isolated for the first time from the species Garcinia schomburgkiana collected at Quang Binh province, Vietnam.</p> 2022-08-09T20:33:42+00:00 ##submission.copyrightStatement## Triterpenoids and triterpenoid saponins from leaves of Bougainvillea spectabilis 2022-08-09T20:42:55+00:00 Nga Thi Vo Lien Thi My Do Quy Bao Pham Tuyet Thi Anh Nguyen <p>The genus Bougainvillea with about 18 species belonging to the family Nyctaginaceae is a widespread group throughout the world. Bougainvillea spectabilis was traditionally used in Indian and Mexico for treatment hepatitis, cough, and diarrhea. Ethanolic and methanolic extracts from leaves and stems of this plant showed anti–inflammatory activity. Some pharmacological studies have focused on antidiabetic activity of this species. Some extracts from leaves, bark exhibited hypoglycemic, -glucosidase, and amylase inhibitor activities. Phytochemical investigations have reported the isolation of flavonoids, triterpenoid saponins, and steroids. Leaves of B. spectabilis were collected and extracted with ethanol at room temperature by maceration method to obtain the ethanolic extract. By partitioning with n–hexane, ethyl acetate successively yields n–hexane and ethyl acetate extracts. Column chromatographies on normal phase silica gel, reversed–phase RP–18, and Sephadex LH–20 were used to isolate compounds 1–6. Their chemical structures were elucidated by HRESIMS, 1D, and 2D–NMR and compared with those reported in the literature, including lupeol (1), (20S)–3β–acetoxylupan–29–oic acid (2), maslinic acid (3), 3–O––D–(6'–O–methyl)glucuronopyranosyloleanolic acid (4), 3–O––D–(6'–O–ethyl)glucuronopyranosyloleanolic acid (5), and 3–O––D–glucopyranosyl–(14)––D–(6'–O–methyl)glucuronopyranosyloleanolic acid (6). All these compounds were isolated for the first time from the genus Bougainvillea.</p> 2022-08-09T20:42:02+00:00 ##submission.copyrightStatement## Effects of nitrogen on growth and nitrate accumulation in mustard green (Brassica juncea L. ) in the hydroponic system 2022-08-15T03:37:09+00:00 Tran Thi Thanh Hien Tran Thanh Thang <p>Nitrate content (NO3-) is one of the important indicators to assess the quality of leafy vegetables. Many studies have shown that vegetables in local markets containing high levels of nitrate that induce harmful effects on human health. In Vietnam, publications on the correlation between NO3-/+NH4 ratio and the nitrate accumulation are limited. Mustard green (Brassica juncea L.) is a popular vegetable and has a high nutrient (rich in fiber and micronutrients). However, the effect of nitrogen on the nitrate accumulation by hydroponic has not been elucidated. In this study, mustard green was grown in four media with different NO3-/+NH4 ratios (2/1; 1.5/1; 3/1, and 4/0) in the hydroponic reflux system. Results showed that the nitrogen requirement of mustard green depended on growth stages. Mustard green needed a low NO3-/+NH4 ratio at the slow growth stage (seedlings) and a high NO3-/+NH4 ratio at the fast one. In addition, the increase of the nitrate content also improved the chlorophyll content in the leaves. The complete removal of +NH4 in the medium stimulated the nitrate accumulation in leaves. The study showed that the suitable hydroponic medium for mustard green was MS medium supplemented with twice KNO3. The KNO3 addition in the hydroponic medium increased the chlorophyll content, the fresh weight, and ensured the content of nitrate (417.59 ± 10.51 mg/kg) within the allowable limits (&lt; 500 mg/kg).</p> 2022-08-15T03:37:08+00:00 ##submission.copyrightStatement##