Two new prenylisoflavones, 3′,4′,5-trihydroxy-8-prenyl-dihydrofuran[2″,3″:7,6]isoflavone (1) and 4′,5-dihydroxy-8-prenyl-dihydrofuran[2″,3″:7,6]isoflavone (2), along with five known prenylisoflavones (3–7), benzylalcohol-4-O-β-d-glucoside (8) and two cinnamic acid esters (9, 10) were isolated from the leaves of Maclura cochinchinensis (Cudrania cochinchinensis). Their structures were elucidated by analysis of NMR (¹H-, ¹³C-NMR, HSQC, HMBC), MS spectra and comparison with the published data. Compounds 4–10 were the first time isolated from this species. Prenylisoflavones 1–4 and 6–7 were evaluated for their in vitro cytotoxic activity on KB and HepG2 cancer cell lines. Compound 4 showed cytotoxic activity against both cancer cell lines with IC₅₀ values of 26.99 and 19.95 μM, respectively. The other compounds were considered as inactive.

Synthesis of tubulysin analogues, containing an N-methyl substituent on tubuvaline-amide together with the replacement of either the hydrophobic N-terminal N-methyl pipecolic acid (Mep) or at both N- and C- terminal peptides with available heteroaromatic acids and an unsaturated tubuphenylalanine moiety, respectively, were described. The in vitro cytotoxic activity by SRB assay on five cancer cell lines for sixteen tubulysins was evaluated. Among them, five analogues exhibited strong cytotoxic activities against five human cancer cell lines, including human breast carcinoma (MCF7), human colorectal adenocarcinoma (HT-29), HL-60, SW-480, human lung adenocarcinoma (A459). Interestingly, one analogue showed the strongest cytotoxicity on all five tested cell lines even much higher toxicity than the reference compound ellipticine. Received: 05 October 2021 Accepted after revision: 02 November 2021 Publication Date: 19 November 2021 (online) © 2021. Thieme. All rights reserved Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

The synthesis of valsartan (1), one of the most currently used pharmaceutical agent in antihypertensive therapy, was described through five steps in an overall yield of 54 % starting from 4’‐methyl‐2‐cyanobiphenyl (2). The key step involved tetrazole ring formation catalyzed by Lewis acid. The structures of synthesized compounds were confirmed by means of NMR and MS spectroscopíe.

Centella asiatica is a herb commonly grown across south and southeast Asia for nutritional and traditional medicinal value. Recent studies have shown that triterpenoids and their glycosides produced by C. asiatica may have applications in modern medicines. It is therefore important to determine how best to culture the herb to maximise the production of bioactive compounds while minimising any negative impact upon the environment or the health of the farmers. We have compared Vietnam Good Agricultural Practice (VIETGAP) with an organic (ORGANIC) production technique in Thua Thien-Hue province, Vietnam. This paper reports the results of the collection and analysis of the fresh mass, the dry mass, the raw ethanol/water extracts, and the levels of the main bioactive triterpenoids: madecassic, asiatic and terminolic acids over the course of two years. We found that the ratios of the dry mass to fresh mass, and extracts to dry mass were similar in both cases, with maximum raw extracts/dry mass ratios of 37% (VIETGAP) and 33% (organic). We have monitored these changes with respect to the seasons and found that the best time to harvest for bioactive compounds in this location is June-September, when the weather is warmer and drier. These results show that switching to an organic production method is not detrimental to the accumulation of valuable bioactive compounds, and we anticipate that application of these results will contribute to increasing the economic and social value of Centella asiatica while reducing the use of agrochemicals which can be deleterious to the environment and the health of farmers.

Tuberculosis is one of the most common infectious diseases in the world, caused by Mycobacterium tuberculosis. The outbreak of multiple drug-resistant tuberculosis has become a major challenge to prevent this disease worldwide. ClpC1 is a Clp ATPase protein of Mycobacterium tuberculosis, functioning as a chaperon when combined with the Clp complex. ClpC1 has emerged as a new target to discover anti-tuberculosis drugs. This study aimed to explore the ClpC1 inhibitors from actinomycetes, which have been known to provide abundant sources of antibiotics. Two cyclic peptides, including nocardamin (1), halolitoralin A (3), and a lactone pleurone (2), were isolated from the culture of Streptomyces aureus (VTCC43181). The structures of these compounds were determined based on the detailed analysis of their spectral data and comparison with references. This is the first time these compounds have been isolated from S. aureus. Compounds 1–3 were evaluated for their affection of ATPase activity of the recombinant ClpC1 protein. Of these compounds, halolitoralin A (1), a macrocyclic peptide, was effective for the ATPase hydrolysis of the ClpC1 protein.